Saturday, December 12, 2009

What Audiophiles Don’t Know About Polarized Water

Even though the mechanism behind how it improves the sound quality of audio gear is still open to debate, is the audiophile world at large ignoring at their on peril by ignoring polarized water as an audio tweak?

By: Ringo Bones

As a really “out there” audio tweak often attributed to Peter W. Belt, the viability of polarized water as a viable way to improve the sound quality of your audio gear did manage to generate a significant cult following in the audiophile community. Even though serious discussion of the “science” behind how it works won’t be a perennial topic in the annual meetings of the Audio Engineering Society anytime soon. But are audiophiles – even the scientific community – ignoring at their own peril on what we can learn about the phenomena behind now polarized water works as a hi-fi tweak?

The polarized water referred to by hi-fi enthusiasts is a north-polarized water that is produced as a result of exposing a bottle or glass of water – usually around 250 to 500 ml – to the north magnetic pole of a magnet (the one marked “N”) for around 2 to 5 minutes. The stronger the magnet, the better. Most recommend drinking the water to make your audio gear sound better. But if we do it this way, does it mean that polarized water is a tweak for the listener, as opposed to the audio component being listened to?

The science behind how polarized water works – and it does work to some degree – has yet to be determined. But there have been recent studies conducted on water that woefully revealed that there is still a ton of stuff that the layman and the scientific community doesn’t know about water – let alone polarized water. Professor Eshel Ben Jacob, a physicist from Tel Aviv University, whose research on water memory after it is exposed to electromagnetic radiation when he noted that the bacteria in the water manifested the memory properties of water that is being exposed to such electromagnetic radiation.

Prof. Jacob recently uncovered during the course of his research that water is capable of carrying complex information despite of its “apparently” simple molecular structure. The preliminary findings of the professor’s research suggest not only a scientifically verifiable explanation behind the phenomena of homeopathy, but also on a new paradigm of water purification.

Something that is less stressful after Prof. Jacob had found out that stressful water purification can cause unnecessary stress in humans and other organic systems. Does this suggest that Prof. Eshel Ben Jacob’s findings suggest that water is capable of carrying information / properties that humans – maybe some who are perceptive enough – can perceive even though our most sophisticated mass spectrometers cannot?

Back in 1994, I was fortunate enough to hike into a remote watershed in my neck of the woods – a 12-hour “ordeal” from the nearest roadside – and managed to witness something that water supposedly can’t do. Bamboo harvesters accidentally left some bamboo in the pool that formed at the base of a pristine spring often used by them as a convenient “watering hole”. Bamboo cuttings aren’t supposed to sprout into a new plant right? But here, an obviously machete-cut section of bamboo managed to sprout roots and stems after being immersed for more than a week in the pristine pool of a remote mountainside spring – another thing water doesn’t supposed to do. Though I kept away from that place because where I came from, if there’s a near-inexhaustible supply of really clean and free drinking water, there are bound to be well-armed insurgents. But I still remember the inextricably invigorating properties of the water from that particular spring.

Another proof that the human senses are more sensitive than the most advanced mass spectrometer was shown in an episode of Mythbusters. On this particular episode, the Mythbusters team tries to prove that through using charcoal filters used to purify water a cheap low-end vodka can be used to taste like top shelf or high-end vodka. The charcoal filter made the cheap vodka taste much closer to top shelf vodka via charcoal filtration. Inextricably though, the mass spectrometer – which was used during the episode to analyze the various grades of vodka - can’t tell the difference between the cheap vodka, the charcoal-filtered cheap vodka and the high-end / top shelf vodka. The mass spectrometer only show water-diluted ethyl alcohol while a professional vodka tester and even novice bar hoppers can tell – make that taste and smell - the difference between cheap vodka and high-end vodka. So the lesson here is trust your senses, they are better than a 20,000 US dollar Fast Fourier Transform signal analyzer or a 50,000 US dollar nanogram-level mass spectrometer.

As Professor Eshel Ben Jacob pointed out the science behind a newly-discovered mechanism still under investigation that stressful purification of water does make most humans who consume them stressed out. Maybe exposing stressfully purified water to the North Pole of the magnet for 2 to 5 minutes de-stresses it. Making one drinking the water more musically receptive thus enabling polarized water to work as a hi-fi tweak in improving the sound of your audio system.

Tuesday, November 24, 2009

Much Ado About Slew Rate

Given that most audio equipment manufacturers seldom – if ever – publish the slew rate ratings of their audio amplifiers, how important does an amplifier’s slew rate rating affect its performance?

By: Ringo Bones

After having the good fortune of visiting a good number of hi-fi shows in the past, I do find it odd that an overwhelming number of audio amplifier manufacturers seldom – if ever – publish the slew rate ratings of their preamplifiers and power amplifiers that they are trying to sell. Of probably thousands of brands and manufacturers out there, I only discovered six audio amplifier products so far that published their slew rate ratings. They are: 1.) Creek 4330R Integrated Amplifier at >40 volts per microsecond, 2.) Audio Research VTM200 Monoblock Power Amplifier (vacuum tube-based) at 40 volts per microsecond, 3.) Audio Research VT200 Power Amplifier (also vacuum tube-based) at 25 volts per microsecond, 4.) Simaudio Moon Rock Monoblock Power Amplifier (solid-state) at 160 volts per microsecond, 5.) Headroom Reference Amplifier Module – a power amplifier for headphones – at 1,300 volts per microsecond, and the 6.) Cinepro 3k6SE Six-Channel Amp with a slew rate rating of 65 volts per microsecond. Given that an amplifier’s slew rate rating is probably the last thing on a typical hi-fi audio amplifier buyers’ mind, what is slew rate anyway and how much of a factor does it play in a typical audio amplifier’s performance?

Slew rate is defined as the rate of change of the output voltage of an amplification circuit. Typically it is expressed as the maximum rate at which the output voltage of an amplification circuit can change in volts per microseconds. If an amplifier, for example, has a slew rate of 1 volt per microsecond it would take 10 microseconds for the output voltage to change from 0 to 10 volts, regardless of the rate at which the input voltage changes. Slew rate ratings also define the bandwidth capability of a typical amplifier design. An amplifier can only amplify a sine wave without distorting it up to a certain frequency as dictated by its slew rate rating. If a sine wave is of too high in frequency for an amplifier to process without distorting it given the amplifiers’ slew rate rating, that amplifier would output a triangular wave signal of higher amplitude instead of a sine wave. Triangular waves contain mostly odd-ordered harmonics by the way.

Audio engineers who would rather “listen” to their amplifier with 10,000-U.S. dollar Fast Fourier Transform analyzers instead of their very own ears tend to disdain in measuring the slew rate of vacuum tube-based amplifiers – especially single-ended triode amplifiers with vanishingly low to zero negative feedback. Because the squashing transfer function typical in these amplifier designs can decrease the odd-order harmonics in the signal they are trying to amplify. A triangular wave being fed into a tube amp’s input may end up looking like a sine wave with a higher magnitude at the output. A good thing about this typical idiosyncrasy of vacuum tube-based amplifiers is that it is not frequency dependent, unlike an audio filter with fixed frequency response. This is probably the primary reason why tube amps – especially ones that don’t use any negative feedback – sound musical and might – with the emphasis on might – give a misleadingly high slew rate rating in comparison to solid-state designs. Despite of all this, how does slew rate play a factor when it comes to the everyday use of our audio pre and power amplifiers?

If you’re fortunate enough to have peeked into a typical high slew rate hi-fi power amplifier, you might have noticed that the “apparent” complexity of its circuit layout and design just to achieve a high slew rate rating may seem a touch of glorious excess, but it is eminently practical. Today’s audio formats – if you’ve already managed to outgrow the typically compressed dynamic range of on-line digital music downloads – demands instantaneous power in order to amplify them realistically as Mother Nature or God in Her infinite wisdom intended.

Since the mid-1990s, the SMPTE movie-soundtrack specifications now permit special effects to peak 20 decibels above the average dialogue level, thus requiring 100 times more amplification power than is needed for dialogue. Using the watt-meter setting of my multi-meter, the average dialogue levels of the DVD of the movie Independence Day in my listening room with my audio system required only 1 to 3 watts of power. But during one of the loudest part of the movie – when the alien saucer blew up the White House – my main amplifiers generated a peak of 250 watts for probably half a second.

This performance – paradoxically - was produced by my 70-watt rated power amplifier equipped with a 300-watt power supply sporting high-speed Schottky Diode / Schottky Barrier Diode rectifiers with Rubicon Black Gate capacitors. This is at a sound pressure level in my listening room that doesn’t preclude casual conversation given that my main speakers has a sensitivity of 93 watts at 1 watt (2.87 volts) at 1 meter. What I’ve learned so far is that not only do you need clean power, you also need it fast in order to produce current music or other audio formats realistically. Though in my case, I tend to gravitate towards the sensitive loudspeaker route. Nonetheless, slew rate ratings is a very important factor indeed when it comes to the realistic sounding playback of recorded music - and movies - in a domestic setting.

Wednesday, October 28, 2009

Memory Distortion: The Bane of Solid-State Amplifiers?

Some audio purist still claim that solid-state amplification is not truly hi-fi in comparison to it’s thermionic / vacuum tube counterpart, is there a reason behind this?

By: Ringo Bones

During the start of the 1970s, the solid-state transistor-based audio power amplifier started to make the price of high-powered hi-fi amplifiers – i.e. over 50-watts – much more affordable. But many hardcore audiophiles complained that transistor-based audio power amplifier didn’t sound as musical as their thermionic / vacuum tube-based counterparts. Even newer MOSFET devices – whose characteristic curves resembles that of a pentode tube – still didn’t sound quite as musical in comparison to their thermionic brethren during their rollout near the end of the 1970s. But is there a reason – hopefully a scientifically verifiable one – that explains why solid-state amplification (transistors and MOSFETS) don’t sound as good as their vacuum tube counterparts?

Back in the summer of 1997, a French amplifier manufacturer – Lavardin Technologies – announced that they have discovered why solid-state amplification didn’t sound as musical as their vacuum tube-based competition. They called the phenomena “Memory Distortion” which Laverdin Technologies describes it during 1997 as “the greatest discovery in analogue audio design in the previous twenty years”. Memory distortion, Lavardin Technologies says, is responsible for the shrillness and mechanical-sounding artifacts identified in solid-state amplifiers. Unfortunately in the intervening years, my “richer” audio-buddies can only listen to Lavardin Technologies’ amplifiers in hi-fi shows because they are so prohibitively expensive when compared to vacuum tube-based amplifiers of similar power output and features. But they swear that Lavardin Technologies' low-powered integrated amps do sound like they use vacuum tubes as power output devices.

Fast-forward in 2009 when one of my audio-buddies managed to purchase one used – although still very costly – one of those Lavardin Technologies integrated amplifier. It is the 30-watt Lavardin IS Reference which sells for almost 4,000 US dollars when brand new. He got one for a shade under 2,000 US dollars, and say’s its all worth it because the single-pair of transistors used in this integrated amp will last for thousands of years when properly used. And they do sound like vacuum tube amps – vacuum tube amps that could drive speakers with tricky impedance curves. Albeit only within their “meager” 30-watt rating. But despite of the obvious overpricing in electronics engineering terms, why do these amps sound so good?

Given our sample no longer has the company’s warranty and my audio-buddy was generous enough – albeit up to a point – to allow our local hi-fi association a peak inside the innards of Lavardin’s famed integrated amps. A look inside might make every “mainstream” electronic engineers accuse of Lavardin Technologies of recto-cranial inversion. Those mainstream folks usually accuse everyone of encasing the circuits of their designs in some kind of black goop in the name of copyright protection, as suffering from recto-cranial inversion. But these has been proven – probably since the 1980s – that it could improve the sound quality by controlling spurious vibrations from affecting the sensitive circuit layout.

Lavardin did divulge the reason why tubes sound better than transistors, which they used to their advantage in making their solid-state amplifiers sound as good as tubes. It was probably the consensus view of quantum physicists who looked into the differences in operation of vacuum tubes and solid-state devices during the 1990s. According to their findings – though it has been noted in every post World War II vacuum tube-based electronic textbook in existence – which start at the basic fundamental differences between vacuum tubes and solid-state devices.

In a vacuum tube any particular electron – i.e. strictly speaking the electron’s wave function – travels through free space, influenced only by the electric fields caused by the various electrodes in the electron’s wave function’s path within the confines of the tube. The control grid’s field hold’s back a proportional number of electrons from the total number of electrons emitted by the cathode, in which a change in grid voltage change’s it’s field and thereby varies the total number of electrons reaching the anode and hence the resulting anode current.

The velocity of an electron by the time it reaches the anode after being accelerated by the anode’s field is truly mind-boggling. As an example, a tube with a typical anode voltage of 450-volts, the electrons will hit the anode at approximately 28 million miles per hour or about 4% the speed of light – which is around 670 million miles per hour in vacuum. Thus the reason for the vacuum tube’s somewhat high-temperature operation. The electrons which make it past grid are the same ones which – a tiny fraction of a second later – appear at the anode and becomes the signal that drives the load.

In a solid-state device – transistors, MOSFETS, and specially including wire – the electrons have a very hard time traversing the entire length of their intended path. In the solid-state domain, electrons have to fight their way through millions of random fields caused by the atoms in the substrate material – usually at 0.001 meters per second. In which calling it a snail’s pace would be an understatement in comparison to an electron’s speed traveled though a typical vacuum tube. Furthermore, it is not the actual electrons which carry the signal, but the influence one electron on it’s neighbors. The message or signal gets carried akin to a “Chinese Whisper” albeit only with less degradation of the signal – hopefully.

This quantum-mechanical explanation of the radical difference between vacuum tubes and solid-state devices is the claim used by Lavardin in explaining how they minimized memory distortion in their solid-state amplifier designs. According to them, memory distortion has to do with the way musical signals have to slog their way through silicon – akin to being stuck in the mud. Transistors hold previous signals in memory – as in the electron’s wave function. And these “residual memories” or remnants of an electron’s previous state - maybe a few tiny fractions of a second before distort the new incoming signals. The musical signals can’t flee the silicon fast enough. But is this explanation sufficient from a scientific standpoint? After all, if “memory distortion” is about timing errors – assuming that the phenomenon is real in the first place – then why is it that there are several, albeit almost unrelated, ways of eliminating the symptoms caused by memory distortion.

James Henriot of Whest Audio also managed to do the same feat of making solid-state amplifiers more musical by eliminating “analog-domain jitter” via his Whest dap.10 processor. Which most users testify that the Whest dap.10 processor improves their already well-sorted CD playback system’s sound quality by making it sound like a big analog open-reel tape, the one often used in better recording studios. I’ve heard this only in hi-fi shows, but my impression of this product seems like it makes your typical solid-state integrated amp sound like a good vacuum tube amp.

While a Frenchman named Yves-Bernard André of YBA also manages to do the same with his solid-state integrated designs by using various techniques holistically to eliminate the symptoms that make solid-state amplifiers sound “inferior” to their vacuum tube counterparts. From using synthetic diamond powder to damp the circuit boards to the resonance control of every component used. Not to mention minimizing to the absolute minimum the inherent hystersis distortion caused by a transistor’s ferromagnetic enclosure. Even though YBA products – as with most French integrated amps - are typically priced way above a typical hi-fi enthusiast is willing to pay, Yves-Bernard André’s holistic approach to designing his solid-state based audio components seems to have removed the symptoms of what we know of as memory distortion.

LFD Mistral MOSFET-based integrated amplifiers also managed to eliminate the symptoms of memory distortion through attention in circuit layout. By orienting the resistors of their LFD Mistral integrated amps in phase on the master board. The resistors on both channels are identically oriented which they believe – and some owners of LFD Mistral integrated amps – is important to stereo imaging. So does the orientation of the wiring and the fuses. Unfortunately, this attention to detail in parts layout doesn’t lend itself well to mass production machinery used in making mobile / cellular phones and i-Pods. But the resulting product is nonetheless spectacular. LFD Mistral integrated amplifiers are often compared to single-ended triode amplifiers in terms of sound quality.

So what does this all mean? Well, it seems like the holistic tweaking techniques utilized by Yves-Bernard André and the LFD Mistral does seem to improve the sound quality of your typical solid-state audio gear – even ones using integrated circuit IC amplifiers. While the Lavardin Technologies may be on to something in explaining the phenomenon of memory distortion, James Henriot’s forays into analog-domain jitter will probably need the collaboration of other scientist with access to the very state of the art testing gear to explore further the phenomena of analog-domain jitter. Who knows that it might result in better and cheaper laptops and mobile phones ten years from now? Maybe memory distortion is just a symptom of bad circuit layout in the production of solid-state gear. Often easily solved via enclosing critical parts in a faraday cage - or by the use of exotic and boutique capacitors like Rubycon Black Gates or Philips-sourced French Blue capacitors.

Tuesday, September 22, 2009

Is the BBE Sonic Maximizer Hi-Fi?

Manufactured during the mid 1980s supposedly as a means to “transcend” the limitations of hi-fi speakers at that time, does the BBE Sonic Maximizer qualifies back then – and now – as hi-fi?

By: Ringo Bones

Now (as in 2009) derided by hardcore audiophiles and “soulful” electric guitar players, I did remember during my high-school days – i.e. the mid 1980s – that a black box with the letters BBE was both revered and coveted in domestic hi-fi circles in my neck of the woods. To the uninitiated – and those who have already forgotten – here’s a refresher of that used to be wonderful black-box known as the BBE Sonic Maximizer.

The letters BBE stands for Barcus-Berry Entertainment Incorporated – later called BBE Sound Inc. when they’re “iconic” black-box / audio processor that became widely used and endorsed by Heavy Metal musicians during the “Hair Metal” era of the late 1980s and early 1990s. The company is located at Huntington Beach, California. Around the middle of the 1980s, BBE Sonic Maximizers began to be widely used for audio recording, motion picture sound tracks, TV and radio broadcasting, and motion picture theatre sound systems. According to the audio processor’s creators, BBE Sonic Maximizers were primarily designed to improve the sonic clarity of virtually any reproduced sound by correcting / compensating for phase and amplitude distortions produced as your typical power amplifier drives a typical loudspeaker system.

My first hand experience of this device was back in 1987 when a rich high-school classmate with similar musical tastes as me got one from his dad while working in the US. It was the Barcus-Berry BBE Model 2002 signal processor, which sold around 500 US dollars at the time. The BBE signal processor was meant to be installed between the signal source(s) – we only had a cassette tape deck and a Technics Quartz Synth tuner at the time – and the power amplifier.

Though my memories of that particular BBE Sonic Maximizer was now somewhat hazy, I can still vividly remember that we often played a track called Digital Bitch by W.A.S.P. (We Are Sexual Perverts?) at the time - Unforgettable because Chris Holmes, Blackie Lawless and the rest of the band probably foresaw the rise of Paris Hilton and her famous antics on the Internet. And as one of the few Heavy Metal bands who gained a strong following in the Punk community – my high-school classmate was actually into Punk / New Wave at the time – W.A.S.P. gained fame (or is it notoriety?) in both camps. Rumor has it that W.A.S.P. were “discovered” by Ed McMahon during the first season of Star Search.

From my present perspective – being my present hi-fi set-up is composed mainly of Electro-Harmonix vacuum tube-equipped and high-speed wide-band solid state exotica. All I can say is that the BBE Sonic Maximizer is nothing more than a “lazy-EQ”. I mean it is just an adjustable Loudness controller on steroids – though I am not denying that it is not useful. Given that at the time, we can rarely crank up our hi-fi sets to “unamplified / no PA system” garage band sound levels. Those rare occations when we can play as loud as possible during my high-school days is usually reserved for band practice.

When you can only play your hi-fi below the actual sound pressure level the music was originally recorded, Loudness and other EQ / tone controls to compensate the Fletcher-Munson Equal Loudness Contour Curves inherent to how our ears perceive airborne sound. To my ears – back then as it is now (2009) – BBE Sonic Maximizers boosts the bass and treble frequencies of the audio signal, depending on how much it’s “process” knob is being cranked.

First impressions on using the BBE Sonic Maximizer usually results in “clarity” – i.e. the boosting of the high-frequency signals usually around 2-KHz to 3-KHz upwards. And this is why many novice hi-fi enthusiasts during the early 1990s who can only afford mass market mini component boom boxes to listen to their copies of Smells Like Teen Spirit by Nirvana became concerned over “tweeter failure”. Especially when the tweeters of their BBE-equipped boom boxes (which became commonly widespread around 1992) heats up when playing the iconic “Seattle Grunge” album that features very distorted electric guitar sound with boosted high-frequencies.

Due to its endorsement and use by top musicians, like Megadeth and Skid Row – guitarists Dave “The Snake” Sabo and Scotti Hill were known to use one - during the early 1990s. The folks at BBE Sound Inc. created a BBE Sonic Maximizer plug-in for PC-based recording, which started to gain popularity during the late 1990s. For domestic hi-fi use, the BBE Sonic Maximizer works very well with budget cassette tape decks that don’t carry the Nakamichi badge to make them sound more “natural”. BBE Sonic Maximizers also works very well to "improve" (...or is that to flatter?) the “sound quality” of FM stations that are seriously addicted to those OPTIMOD compressors. And data reduced digital music downloads like MP3s. But if it is up to me, I would rather use the vacuum tube-based Pultec Model EQP-1R studio equalizer. This vintage studio equalizer - probably dating back to The Beatles era Abbey Road Studios - has 12RX7 and 12RU7 preamplifier vacuum tubes that can put to shame the BBE in sound quality terms.

Unfortunately, BBE Sonic Maximizers are an anathema to vacuum tube hi-fi aficionados and “soulful” electric guitar players because they tend to make their gear sound like cheap solid state. Like a brand new 10,000-watt audio power amplifier with a manufacturer’s suggested retail price of 200 US dollars. Surprisingly, BBE Sonic Maximizers can often be found in pawnshops or other establishments that sell pre-owned music gear somewhere between 50 to 100 US dollars. So it is somewhat a cost-effective way for the curious and uninitiated to experiment – or experience first-hand - what this BBE audio processing brouhaha is all about.

Monday, September 14, 2009

An Op-Amp IC For Your Hi-Fi Needs?

Given that they’ve been used successfully in a number of excellent sounding hi-fi applications, is there really a right op-amp for your audiophile needs out there?

By: Ringo Bones

Yes it’s true, there really is such a thing as an audiophile grade integrated circuit operational amplifier or IC op-amp. And most of them are not necessary manufactured by Analog Devices like the AD845 and AD843. Or those by Burr-Brown which their dual op-amps that are specified to be fast enough to handle the RF energy present in Red Book CD digital to analog conversion are often used in bridge configuration in left / right analog outputs.

The quest for finding the best off the shelf IC op-amp probably started during the early 1990s. When major CD player manufacturers discovered – either by theoretical introspection or trial and error – that those high-speed op-amps made their 500 US dollar or so CD players sound closer to entry-level audiophile grade vinyl LP replay.

From the electronic engineer’s design standpoint, high-speed op-amps are a necessity in Red Book specification CD players. Sufficient slew rate ratings are a necessity to handle the quite large amounts of ultrasonic requantization noise - which is an unfortunate by-product of converting your 16-bit 44.1-KHz digital data into a reasonably smooth analog waveform that could sufficiently past muster as music. In my experience with the most widely used up-market “hi-fi” op-amps – namely the LM318 and the LF356 – which have very different personalities when used in an audiophile context. Although I used audiophile grade ceramic IC sockets with silver connectors to allow me to easily replace both op-amps for comparison.

Over the years, my countless experiences with the high-slew rate (50 volts per microsecond) LM318 suggests that this IC op-amp is well suited to audiophiles who like to listen to Classical Music - Or wants to reproduce the recorded hall acoustic of an opera recording accurately played back in his or her listening room. It even enhances – or exaggerates – the Classical Music-like hall acoustics of some tracks of The Gathering’s “How To Measure A Planet?” album.

One drawback of the LM318 op-amp though is that it doesn’t like very much the “relatively” high-capacitance interconnects often used in entry-level solid-state audio gear. Like Monster Cable’s mellow sounding M850i interconnect often used to tame the harshness of cheap solid-state audio systems. Resulted in a high-pitched squealing sound on rare occasions (guaranteed more than once) during turn on. Although easily remedied by turning off and turning on again your entry-level solid-state amp.

Even though from a technical standpoint, the LF356 has a much lower slew rate rating (12 volts per microsecond) in comparison to the LM318, it does audiophile-oriented things that the LM318 can only aspire to. The very high input impedance – about 1 trillion ohms - of the JFET input stage of the LF356 allows it to have a bass response that Rock Music aficionados since the time of Elvis strive for. The LF356 is also capable of driving large capacitive loads – up to 10,000 picofarad or 0.01 microfarad – with ease. Which makes it more suitable for driving high-capacitance mellow sounding interconnects used in entry-level solid state gear.

Sound quality wise, it is as if the designer of the LF356 op-amp want it to sound like what recording engineer Andy Johns wants the first four album of Led Zeppelin to sound like – i.e. the “John Bonham snare sound”. The LF356 also sound as if it is the first op-amp with a very musically ideal loudness control. It defeats the Fletcher-Munson contour curve characteristic of the human ear that makes us less sensitive to the bass and treble frequencies when listening at reduced sound volume levels. With the LF356, you’ll get the full works whether you’re playing at 65dB or 95dB sound pressure levels - not unlike the sound of Electro-Harmonix versions of 12AX7 preamplifier tubes.

Surprisingly, the LF356 does room sound too - Although not like the Classical Music concert hall portrayed by the LM318. The room sound produced by the LF356 is the “normal” unadorned type – typical recording studio or just a spacious venue. The LF356 also has better low-level sound retrieval in comparison to the LM318 because the LM318 tends to exaggerate the dynamic range of CDs that are recorded without Tom Lord-Alge levels of compression. Like Lunachick’s Binge and Purge album which the LF356 still manages to retrieve low-level details that are played back even softer by its higher slew rate counterpart.

Both can still benefit from a well-regulated plus and minus 15 volt split supplies though, given the inherent RF corruption of our contemporary power lines. Despite both IC op-amps often rated with a power supply rejection ratio of over 100dB at 50 to 60-Hz AC. Boutique capacitors like Rubicon Black Gate capacitors or Philips sourced French Blue capacitors also help improve sound quality to no end.

So there you have it, two op-amps that I have extensive experience with that could past muster as being audiophile certifiable. Although it is somewhat over simplistic to conclude that one prefers Rock, while the other op-amp prefers Classical. The sound quality of one is sufficiently different from the other that it is worth noting. Although the LF356 also has a gorgeous presentation with Orchestral Classical Music recorded during the Golden Age of Stereo.

Monday, September 7, 2009

Are Integrated Circuit Operational Amplifiers Hi-fi?

In the current fashion “revival” of vacuum tube and discrete transistor usage in the hi-fi scene, are audio designs that use integrated circuit op-amps still considered hi-fi?

By: Ringo Bones

Integrated circuit – or IC – op-amps have a myriad of advantages over their discrete component-based counterparts other than space. Like extremely high input impedance, high common mode rejection ratio and high power supply noise rejection ratio just to name a few all in a very compact package. But in terms of ultimate sound quality, many top designers in the hi-fi world find the sound quality of most IC op-amps wanting.

Richard Fryer, founder and owner of Spectral Audio – one of the top manufacturers of cutting edge solid-state audio gear, who as recently as 1998 still insist on using discrete circuitry. As opposed to integrated circuit chips much of the time. Fryer and his design team at Spectral Audio had found out over the years that for critical signal applications, integrated circuits – or IC chips to you and me – simply don’t meet their quality standards. Although he and his design team had been constantly evaluating new integrated circuits and, to everyone’s credit, the IC chips are getting better and better through the years. Still in the rigorous evaluations that the design team at Spectral Audio does these “improved” IC chips simply can’t pass the microphone feed accurately. There’s so much musical information and life that is lost – according to Fryer. Even with the most premium integrated-circuit amplifiers, these integrated circuit packages are just not up to Spectral Audio’s needs in critical signal applications.

Even though most audio designers in the hi-fi world still insist on using discrete components, there are those who are adventurous enough to use IC op-amps in their cutting edge audio designs. Ron Sutherland is one of those high-end audio gear designers who isn’t afraid to use IC op-amps in his almost 7,000 US dollar Sutherland PH-1 phono preamplifier. Maybe it is because Sutherland has a degree in both electrical engineering and physics that made him courageous enough to use a number of Analog Devices instrumentation integrated circuit op-amps on his somewhat “pricey” but very good sounding phono preamplifier.

Another upmarket high-end audio gear that uses IC op-amps is Reflection Audio Design’s 4,700 US dollar (550 US dollar extra for a phono stage) OM1 preamplifier. The OM1 preamplifier is a high-speed, super wide-bandwidth design based on very high slew rate IC op-amps rated at 2,000 volts per microsecond slew rate. It is purported to be flat to 2 megahertz and able to maintain an absolute phase of plus and minus 0.5 degrees across the audio bandwidth (20 Hz to 20,000 Hz). The OM1 preamp by Reflection Audio Design is a very pretty two-chassis affair – if you include the matching 1,550 US dollar battery unit – with a high level of attention to detail. Like the use of curved circuit traces to avoid high-frequency signal reflection.

There are also budget high-end audio designs that used IC op-amps. Like the Super Pas 4 i preamp kit which famed Dynaco tube amp tweaker Frank Van Alstine sold in the early 1990s. Though this preamplifier is somewhat unique because it is a tube and op-amp IC hybrid. Comprising of two 12AX7 tubes and two AD845 (AD843) FET input op-amps in the output stage. And it is surprisingly affordable – in high-end audio terms – at 595 US dollars back in 1993.

In my personal experience, op-amp IC chips – when used properly – can achieve excellent results sound quality wise. Sometimes I wonder why all brand-name boom boxes being flogged in the “high-street” can’t achieve excellent sound quality that matches even cheap DIY hi-fi that uses op-amp chips. Even DIY-ers had achieved excellent results with these lowly audio devices. Most of these serving as a gateway to the wild blue yonder of high-end audio. Next time, I’ll be discussing my experiences with the most touted op-amps for audio use, the LF356 and the high slew rate LM318 in a DIY hi-fi context – replete with unapologetic tweaks.

Sunday, August 9, 2009

Does Cranking the Bias Current Make a Better Tube Amp?

Many swear that it improves high frequency performance, but does cranking up the bias current a sensible way to improve high frequency performance of your tube / valve amplifier?

By: Ringo Bones

This thorny issue started in my neck of the woods during the tube / valve amp revival of the mid-1990s. Where everyone with a still-working 6L6-equipped 1965 Fender twin of a EL34-equipped Marshall amplifier found out that these rock guitar workhorses can be made into very righteous hi-fi amps by jacking up the output tubes’ bias currents and connecting them to domestic hi-fi loudspeakers. And after the news arrived that a fresh batch of tubes / valves are only a plane ride away in neighboring Hong Kong, thus turning every tube-based guitar amp toting guitar hero wannabe curious about hi-fi into ad hoc tube / valve electronic experts almost overnight. The frenzy of everyone in my place born way after astronauts Armstrong and Aldrin first walked on the surface of the Moon scrambling in a Manhattan Project-like zeal to make their tube-based guitar amps do double duty as audiophile quality hi-fi amp-on-the-cheap. Is probably the most surreal manifestation of anachronism I will ever see in my entire life, but does the price of their blissful ignorance worth more than they bargained for?

11 years ago (in 1998), I was in the process of fulfilling my personal tour-de-force of constructing a Black Face Fender Champ on steroids. It was a single-ended guitar amp based on the Russian GM70 transmitter tube / valve that I found for sale rather cheaply – 2 for 15 US dollars – in a garage sale. This rather “gigantic tube” has an anode dissipation of 250 watts and requires a power supply of 1,500 volts DC. The only “substantially expensive” parts of my Black Face Fender Champ on steroids was an output transformer by Audio Note that can handle the GM70’s 1,500 volt DC power supply brought used from an “disenfranchised” hobbyist for about 50 US dollars. And a Japanese-sourced OEM Leslie-type organ speaker cab from the 1970s being heavily discounted by our local flea market because no one ever bought it since it went on display back in 1979. The flea market’s storekeeper very gladly sold it to me for about 20 US dollars. Luckily the other components required for my project amp had been lying around in my spare equipment trunk. It wasn’t long before someone in my neighborhood haggled me to part with it for about 1,000 US dollars.

At the time this was a very good deal because I’ve only probably spent about 250 to 300 US dollars creating my ultimate guitar amp, plus I desperately needed the money to bribe into a lucrative government job to pad my résumé. Sadly the new owner began cranking up the output tube’s bias current to accentuate the Black Face Fender Champ on steroids’ very beautiful high-frequency timbre. Allowing the big tube to fail 7 months later. Coming to his senses, he backed up the bias to normal and the “spare” GM70 tube still played to this day (2009).

By their very nature, tube-based electric guitar amplifiers don’t work particularly well as uncompromising audiophile-grade domestic hi-fi amplifiers. Especially if the musically-inclined user discovers the “virtues” of reducing the negative feedback levels of his or her electric guitar tube amp as a hi-fi amp set-up. Though zero-feedback tube / valve amplifiers are well known for retrieving the subtle nuances of the acoustic environment of recorded music, redesigning your guitar amp’s negative feedback to zero could destroy the tweeters of your domestic hi-fi loudspeakers. Especially since an overwhelming majority of guitar amplifiers output transformers are not purposefully wound to work in a zero negative feedback tube-based amplification circuitry. Let alone designed using a Fast Fourier Transform.

EL34 equipped Marshall amps are the most often tweaked by this method to adopt them for domestic hi-fi use. Most of these types have an H.T. of about 440 volts DC when measured between the plate (pin 3) and the cathode (pin 8) of the EL84 tube / valve. Most EL34 push-pull power amplifiers are fitted with access pins / ports where you can insert the + and – test terminals of your voltmeter / multi-tester / multi-meter to allow you to adjust the bias current of each tube. Usually this is composed of a high-wattage 10-ohm resistor – usually designated as Rs and is connected from the pin 8 of a particular EL34 to the circuit ground. When you attach your voltmeter at this test point, it is effectively in parallel to an internal 10-ohm resistor or the Rs resistor.

Setting your voltmeter / multi-tester to the 1-volt range, if the voltage reading across this point is 500-millivolts or ½ volt, you can use ohms law to compute for the bias current of the particular tube you are measuring – i.e. current = voltage / resistance. Which at 500-millivolts / 10-ohms = 50mA or 50-milliamperes of standing current or bias current. Using this data, you can now compute the EL34 tube’s power dissipation in the amp you are testing. Using Ohm’s law formula to obtain power P=IV or P = 50mA multiplied by 440 volts = 23 watts, which will be the power dissipation of the EL34 tube as used in the particular amplifier design you are measuring. Though the voltage of the H.T. and the resistance value of the Rs resistor could deviate by as much as 10% during normal use.

From a design standpoint, the EL34 tube / valve and its derivatives – like the 6L6, KT77, KT88, 5881, 6550, 6CA7 tubes – were rated by their original manufacturers during the “Golden Age of Stereo” for a maximum anode dissipation of 25 watts and exceeding this rating will drastically shorten tube / valve life. This is so because the excess heat generated by exceeding the tube’s anode dissipation will cause the anode to release what is known as occluded gas, which damages the delicate cathode coating reducing electron emission. Some types of EL34 tubes / valves – especially ones manufactured in Eastern Block countries and China during the 1980s – may also have a low emission to start with and cranking up the quiescent bias current / standing current could cause the tube / valve to saturate on peaks / high-level signals, causing distortion.

Many veteran tube / valve amplifier designers suggest that if you are after extended output tube life, you shouldn’t run EL34-type tubes at over 20 watts of total anode dissipation to lessen the heat generated inside the tube / valve. Unfortunately, cranking up the bias current on these types of tubes usually results in an “improvement” of their high frequency response – i.e. a subjectively much louder high-frequency sound output. Which can be addictive when it comes to tube amps because of their really sweet and grain-free presentation of high-frequency audio information. Some are even known to crank up the quiescent bias currents of the tubes of their EL34s up to 85mA, making the tubes less likely to last more than eight months when use at an average of eight hours a week.

If you want to make the high-frequency response of your tube-based electric guitar amp “seem” louder, do what Queensrÿche does during the late 1980s. Replace the 12-inch Celestion speakers of your Marshall cabs with JBLs. Or if you can afford them 15-inch Leslie-derived organ speakers equipped with a whizzer cone similar to the one used by Jimi Hendrix when he recorded Little Wing in the studio back in 1967.

For those with a more thorough knowledge in tube / valve-based electronics, another method of increasing the high-frequency output of your tube-based electric guitar amplifier is to modify the preamplifier section. The majority of tube-based guitar amps being sold today still use the “conventional” 12AX7-based double-triode phase splitters in their preamplifier sections. The problem with the conventional double-triode phase-splitter is it’s high input capacitance caused by the Miller Effect. This causes high-frequency loading on the input (12AX7-based?) tube and reduces bandwidth, making it very difficult to use appreciable amounts of negative feedback - especially with 6L6 Beam Power Tetrode and EL34 Pentode output tube designs – without instability due to the phase shifts incurred. By the way, negative feedback is a necessity when extracting the maximum output power obtainable of relatively “modern” output power tubes like the 6L6 and the EL34.

Low noise R.F. pentode preamplifier tubes can be used as a better phase splitter in the preamplifier section of tube-based electric guitar amps because a pentode has a very low input capacitance and high gain due to the shielding effect of the screen grid. This means that the capacitance loading on the input tube (12AX7) is greatly reduced, increasing bandwidth and decreasing troublesome phase shifts.

Or if you want the ability to experiment lowering the negative feedback of your electric guitar amp or operating the output power section in triode mode without your amplifier breaking into spurious oscillation. Which could destroy tweeters when you used your tube-based guitar amp as an ad hoc hi-fi tube amp, then use beefier preamplifier tubes like the 5687 tube. The 5687 tube can dissipate 4 watts, it’s dead linear, needs less drive current, and has a low output impedance. Making it able to be used as a driver stage of an inter-stage transformer (Does this remind you of the AN214 driving the inter-stage transformer of an MJ2955-based transformer-coupled booster amp?). If you go with this redesign route, the output tubes of your guitar amp could be configured in self-biased or auto bias mode due to the secondary winding of the driver / inter-stage transformer as opposed to their de rigueur fixed bias configuration.

Auto bias has the advantage of providing automatic compensation of tube variability characteristics, so tube matching and individual bias adjustment will no longer be necessary. Though matched pairs of tubes are still desirable. Auto bias gives that sweet, easy sound tubes possess. Fixed bias gives more power, but a harder sound. In my experience, output tubes of auto-bias configured tube amplifiers tend to last forever. My neighbor’s 300B-based auto-bias amp still uses tubes that he purchased back in 1996 without any degradation in sound quality.

Another way of retaining the de rigueur double-triode preamplifier – i.e. 12AX7 tube-based preamplifier – of your guitar amp is by selecting an output tube designed with a higher mu or a high mu version. I have tried this in the past and it does work but it needs power supply / H.T. circuit modification of your guitar amp. The advantage of this route is that high-mu version of your typical output power tube – like the EL34 and 6L6 – are easier to drive, thus retaining the 12AX7 pre-amp tubes. The caveats include complete redesign of the power supply since high-mu tubes require higher supply voltages than the 450 volts DC needed by your typical output power tube / valve. Some of them needs the power supply / H.T. voltage to be raised to 1,500 volts DC in order to enjoy the maximum benefits of high-mu power tubes. Which can be a problem since power supply capacitors capable of handling 1,500 volts DC are somewhat rare, plus the output transformer needs to be changed to a type that can handle such voltage or your loudspeaker will be turned into a dazzling pyrotechnics display.

Though if you change the choke / inductor filtering the 12AX7 pre-amp tubes to one with a higher inductance – therefore higher DC resistance to lower the incoming voltage supplying the pre-amp tubes, the 12AX7 tubes will be fed with a highly-filtered H.T. DC voltage whose hum is now vanishingly low. Another caveat of this design route is that the output impedance of your guitar amp will now be higher than before – i.e. reduced damping factor – which your amplifiers tonality will be readily be affected by a loudspeaker with a widely-varying impedance curve across the audio band. Although guitar amplifiers that uses minimal amounts of negative feedback and high output impedance are known for their excellent musical performance, so you could probably design an electric guitar amplifier that could double as an excellent sounding domestic hi-fi audio amplifier using this route.

Tuesday, July 21, 2009

The Flat Earth Ideology

Superseded during the 1990s owing to the increasing popularity of vintage low-powered tube amps and very sensitive loudspeakers, is the Flat Earth ideology a vital part of audiophile history?

By: Ringo Bones

Back in the middle of the 1980s, a prominent audiophile sect staunchly believes that the only boxes – i.e. loudspeakers – to have at the end of a righteous audio system should have the word "Linn" written at the back. This somewhat “extremist” hi-fi ideology was aided by enthusiastic hi-fi dealers of the period who are also audiophiles. Not to mention a certain since-defunct periodical / hi-fi magazine called The Flat Response. Thus allowing the hi-fi maker Linn to harbor the ideology that the first priority of a loudspeaker should be the way it played rhythms and the current long-standing global audiophile community’s perception of what is the British Sound was born. Though a Thomas Dolby song from the period titled “Flat Earth” is often played through these systems, reinforcing the need of spot-on rhythm and timing when playing eighties-era synthesizer-based music, but countless others probably use theirs to unravel the rhythmic complexity of Iron Maiden’s The Number of the Beast album.

The most uncompromising embodiment of this hi-fi ideology was the Kan, a tiny box manufactured by Linn. Equipped with treble and mid drivers similar to that used in Linn’s flagship brand the behemoth-sized Isobarik loudspeakers. Back around the middle of the 1980s, the Linn Kans was capable very captivating performance. These loudspeakers sounded extremely fast and extremely tight, with an “uncanny” ability to disappear into their own soundstage. Linn’s bigger – and more efficient – loudspeaker models never convincingly displayed the ability of the smaller Kan’s hi-fi slight-of-hand.

The Kan also has a profoundly fussy approach to matching ancillary components, ironically the little speaker’s “soul-mate” is an equally fussy solid-state power amplifier made by Naim called the NAIT that produced only 30 watts into an eight-ohm load. But during that era in the 1980s, the little Kan – if you wanted more than a squeak from these relatively inefficient speakers - was often paired up to a large muscular solid-state full complementary direct coupled amplifier with a power output of around 80 to 100 watts into an eight-ohm load. The hi-fi community’s renewed obsession with flea-powered tube / valve amps and Maytag washing machine-sized horn loudspeakers were still a decade away.

On the front-end side of things, Flat Earth systems didn’t like inferior source components. CD players circa 1983 was excruciatingly painful-sounding when played through the Kans, plus the early CD’s still suboptimally designed output filters produced so much rhythmic and timing anomalies that it negates the idea of having a Flat Earth system in the first place. Meaning in those days, it was Linn’s pre-braced plinth Valhalla LP12 with LVX+ and Basik cartridge, a Roksan Xerxes, or nothing.

The “dark side” of the Flat Earth ideology is that it made every audiophile – especially in merry old England – harbor the belief that tube / valve amps (especially low-powered ones) from the Golden Age of Stereo were deemed obsolete during the go-go eighties. The Flat Response hi-fi magazine didn’t helped matters either because reviewers of the Flat Earth disposition showed scant knowledge and interest when it comes to the science – and art – of loudspeaker matching. Using quintessentially 1980s era hard to drive loudspeakers with which most tube amplifiers played through them had to struggle. Maybe it was the sound of Leak Stereo 20s wheezing and groaning under the load of a pair of Linn Saras that many Flat Earth-leaning audiophiles conclude that tube amplifiers are now – in the mid 1980s – obsolete. Thus benefiting hordes of East Asian vintage audio enthusiasts.

Thursday, July 9, 2009

Vintage Audio Gear: More Hype Than Hi-Fi?

Given that the laws of progress dictates that the latest technology is surely better than yesterday’s, are some audiophile’s obsession with old / vintage audio gear beyond common sense?

By: Ringo Bones

Since the 1970s, people who buy aggressively marketed 500 dollar audio gear then listen to them with 10,000 dollar audio analyzers had been ridiculing us audiophiles who buy reasonably-priced audio gear of several years vintage then listen to it with our own two ears. Sadly, this vulgar act of “bullying” resulted in a minor – albeit tragic – disaster of vintage audio gear being diverted into the Far Eastern markets. This “disaster” affected mostly American and West European audiophiles and it took twenty years – more or less – to mitigate.

It is safe to point the blame at mainstream consumer electronic manufacturers who probably discovered during the 1970s that audio gear that measures perfectly on the test bench is far cheaper to manufacture than a really good sounding one that measures slightly worse. Thus, the mainstream consumer electronic manufacturers began aggressively marketing their latest audio gear – especially audio amplifiers – based on specs like total harmonic distortion, power output, etc. instead of ultimate sound quality and / or musicality.

During the 1980s vintage audio gear – especially vacuum tube-based audio amplifiers – began to skyrocket in price, especially in America where vintage audio gear manufactured during the Golden Age of Stereo began to appear in garage sales and weekend swap meets. It is not just trusty tube-based receivers, like the venerable Fisher 500-C that gained sacred cow status. Not to mention McIntosh tube-based audio gear. Even vacuum tubes, especially new old stock (NOS) versions of 12AX7 pre-amp tubes, Western Electric 300B tubes, KT-66, KT-88, EL-34 output tubes. And even the 7591A output tubes used in the Fisher 500-C receiver began to skyrocket in price soon after because American electronic manufacturers find that it is not economically viable - during the Reagan Administration - to manufacture vacuum tubes in quantities that would only cater audiophiles and electric guitar players. Exotic capacitors, like Sprague Vitamin Q paper-in-oil capacitors, also followed suit into cult status. Add to that the inherent unreliability of tubes manufactured in t People's Republic of China during the 1980s when compared to NOS American types - thus producing the Perfect Storm of "criminal pricing" of vintage audio gear from the Golden Age of Stereo.

Sadly, your typical Far Eastern vintage audio enthusiast had been busy swallowing up these under-appreciated aspects of Americana – if you’re willing to believe the hype in the hi-fi press anyway. Not just American-made vintage audio gear, even tube-based ham radios and electronic test equipment had already become hot collector items in Japan and other affluent parts of the Orient. Maybe there are plans in Japan for a musical based on the movie Frequency. You know, that move where James Caviezel’s character managed to contact his father played by Dennis Quaid using a tube-based ham radio 30 years in the past due to a freak solar storm.

But in reality, not everyone in Japan is a vintage audio enthusiast. Only those who have the time, money, and living space to indulge – and enjoy – choose vintage audio gear as their hobby. Because a typical pre-global credit crunch salaried employee in Japan who earns a middling income usually lives in a cramped 425 square-foot apartment. Thus very unlikely to invest – and indulge – in a vintage stereo system that costs more that a third of his annual salary and takes up most – if not all – of the space in his living quarters. So PX25 tube amps and 1950s-era Tannoy horn loaded speakers are out of the question.

The good news is that from a financial perspective, indulgence in vintage audio gear is no longer comparable in cost to a two-week working vacation in the International Space Station like it did during the 1980s – it is much, much cheaper now. Not to mention the availability of solid-state amps that sound just as good as tube-based amps since the mid 1990s – well, good enough if you consider the retail price anyway. But the primary reason why vintage audio gear had become a way less expensive hobby during the 21st Century is that some well-meaning folks and manufacturing firms have restarted making vintage audio gear and their associated parts – not to mention better-sounding audiophile-grade compatible replacement equivalent parts – at very reasonable prices. Like the Electro-Harmonix version of the 7591A output tubes by Sovtek of Russia so that everyone can restore their Fisher 500-C receiver without having to spend family car prices.

Looks like 2009 is going to be a very good time for the vintage audio enthusiasts. Unless some speculative swine starts to create hype over discontinued and rare solid-state components, like the AN214 IC amplifier, or the XR2206 Monolithic Function Generator IC and its related kit. And the bad news is that it has already begun because since 2001, the AN214 IC – if you can still manage to find one – was being sold at prices above what a Telefunken 12AX7 pre-amp tube used to sell. Maybe you should hold on to that Sansui AU-a707DR integrated amplifier before selling it to this Sunday’s garage sale.

Sunday, June 28, 2009

Do Musicians Make Better Audio Gear?

Given that they are familiar with music on a regular basis, do musicians – with the requisite electronic engineering skills - make better sounding audio / hi-fi gear than their non-musician counterparts?

By: Ringo Bones

Academic researchers have shown that the great mathematicians – or mathematically literate scientists and engineers - of the past are also accomplished musicians, or at least playing a musical instrument on a recreational basis. A good example would be Albert Einstein relaxing while playing the fiddle. But given that designing really great audio gear requires electronic engineering skills that are derived from mathematics, would “musically literate” audio engineers have an edge over their non-musical counterparts when it comes to designing great-sounding audio gear?

Before he became famous as a recording engineer and creator of probably the best-sounding solid state amplifiers in the world, Mark Levinson once played upright acoustic bass with Paul Bley back in the mid-1960s. Mark Levinson amplifiers are not only praised for their excellent bass performance, but also for their excellent portrayal of the soundstage of the recorded music being played back. Every Mark Levinson audio gear was often cited to be able to create surround-sound playback from just two speakers. Really someone whose audio engineering skills deserve a Nobel Prize if there was a category for one.

Musical Fidelity’s managing director Antony Michaelson not only designs great sounding audio equipment that is sold across the hi-fi price range, from the US$500 Musical Fidelity X-A1 amplifier to the US$6,500 Musical Fidelity kW DM25 two-box CD player (though I don’t think this is Musical Fidelity’s priciest product). But he also plays clarinet. He’s even on the Mozart Clarinet Concerto K622 in A Major CD as the clarinet soloist. Even though Antony Michaelson is a Classical Music-based musician, his audio gear is “eclectic” enough to handle every genre of music known to mankind, from Central Asian acoustic folk music to extremely high-decibel stadium Heavy Metal.

Interestingly, manufacturers of electric guitar amplifiers have entered into the hi-fi business too. Randall Smith of Mesa Engineering - more famous for their vacuum tube-based electric guitar amplifiers with vacuum tube-based rectifying diodes in the power supply – has introduced the Mesa Engineering Baron and the Tigris as “domestic” hi-fi amps. His designs may not make “decent” engineering sense in the 21st Century when high speed solid-state devices that can be used to construct a RADAR system that can “see” stealth aircraft is now commonly available (and surprisingly cheap), but for us music-loving audiophiles, there’s just no substitute. If Randall Smith can design audio gear of such beauty sound quality wise while probably wailing away with his preferred electric guitar and amp combo, then maybe the executives at Sony or any major / mainstream consumer electronic manufacturers should start giving their audio engineering staff music lessons.

If you’re into music that’s been recorded during the Golden Age of Stereo – i.e. late 1950s to early 1960s – there’s just no substitute for tube amps with tube rectifiers. Like the recordings of such soulful artists like Nina Simone. Whose voice can range from crystal clarity to a throaty roar even in the same phrase; In order to appreciate this kind of music you need an audio amplifier that “sweats with the music”. Check out “Break Down and Let it All Out” or Nina Simone’s Francophone opus “Ne Me Quitte Pas” being played on a tube amp with a tube rectifier section, and you’ll swear that she’s alive and in your listening room.

As with all math-driven endeavors, engineering audio equipment – like engineering a weapons system that can throw a 4-gram projectile 938 meters per second with a guaranteed head shot accuracy at 800 meters – is still for all intents and purposes more of an art than a science. Given that we listen with our own ears – as opposed to a US$9,000 audio analyzer – how a piece of audio gear sounds is more important than how it measures on the lab bench. Maybe audio designers who think that it’s all about engineering should try working as an apprentice at Alexander Arms or Knight's Armory.

Tuesday, March 31, 2009

Unseemly Audiophile Demo Discs

Given the lack of Heavy Metal of Seattle Grunge audiophile recordings, can adventurous audiophiles still enjoy “unseemly music software” being played on their systems?

By: Vanessa Uy

When the high-end hi-fi market became established during the 1970s, believe it or not, stadium rock from the same era used to hold audiophile demo disc status. Not-so-old-timers (or is that anoraks?) used to remember the time when both rock bands Boston and Heart as the preferred audiophile demo disc. Unlike today where the de rigeur audiophile demo discs are The Ultimate Demonstration Disc: Chesky Records’ Guide to Critical Listening (UD95) or the Stereo Review Chesky Records Gold Stereo and Surround Sound Set-Up Disc (CHE151). But as we enter into the second decade of the 21st Century – hopefully not kicking and screaming – how many of us hardened audiophiles still get enjoyment from playing “mainstream” recordings in our well-sorted audiophile approved audio set-ups?

Believe it or not, veteran audiophiles could easily get bored with their de rigeur audiophile demonstration and test discs. Despite of using them to impress their non-audiophile (civilian?) neighbors and audiobuddies to show how their latest hi-fi tweaks managed to make the recorded sound of the snare and cymbals played on their system sound more real. But how often does he takes out yet again that Mobile Fidelity Sound Lab pressing of Nirvana’s Unplugged in New York when the mood strikes? So hang on to your audiophile demonstration and test discs cause here’s a list of my personal favorite Top 5 Unseemly Audiophile Demo Discs:

1. Gov’t. Mule – Dose; If David Chesky ever wants to release an audiophile quality American Classic Rock album, he should collaborate with these guys and their recording engineer. A very good example of how electric guitar recordings recorded in a recording studio should sound.
2. The Gathering – How To Measure a Planet?; Quite a contrast to the Gov’t Mule’s guitar-based rock because this particular The Gathering album shows how a Gibson Les Paul and Marshall amplifier sounds when played in a Classical Music concert hall as opposed to an acoustically-treated recording studio. Check out the song Travel to know what I’m talking about. Postscript, the band’s recording engineer could have used an excellent sounding digital reverb but his or her efforts should be commended for producing an inexplicably good result.
3. Veruca Salt – Eight Arms to Hold You; An excellent album – especially the American pressing of the CD - for testing your audio system’s slew rate and transient intermodulation distortion capabilities. In short, your audio systems capabilities of differentiating between Nina Gordon and Louise Post (transient intermodulation distortion) and if you can play this album without giving you a headache at garage-band sound pressure levels (slew rate capabilities). Probably the best album to show off the capabilities of a Michell Argo HR pre-amp to those Veruca Salt fans fortunate enough to afford one.
4. Just Say Noël - Christmas Album; a collaborative effort of Christmas tunes from Sonic Youth and company for the benefit of Peter Gabriel’s Witness. The CD sounds as if it is HDCD encoded even though it is not (it is that good sounding!). A good balance between songcraft and audio production values makes this CD unfatiguing over long listening sessions. Probably the most eclectic – in terms of musical genre – Christmas album ever. Not to mention the “least tacky” – aesthetic wise - contemporary Christmas album ever.
5. Lunachicks – Pretty Ugly; Even though their Jerk of All Trades is the better album in terms of sound quality. As an audiophile demo disc, Lunachicks’ Pretty Ugly is a good CD to check your system’s subwoofer’s bass capabilities. Believe it or not, the song What’s Left managed to misalign / destroy a Velodyne subwoofers accelerometer when one of my older audiobuddies used this particular track in testing subs back in 1998.

So there you have it, there probably is no accounting for taste but these five CD’s represent my current often used unseemly demo discs in evaluating hi-fi systems. I could go into detail about my current often used unseemly vinyl audiophile demo discs. Like the Japanese 45-RPM vinyl pressing of Avril Lavigne’s Basketcase – which is by the way a remake of Greenday’s - sadly only available in neon / day-glow fuchsia pink-colored vinyl. Or my Minty Fresh vinyl pressing of Veruca Salt’s American Thighs, but that’s for another day.

Tuesday, February 24, 2009

Was the Cassette Tape Good Enough?

Is the current popularity of on-line downloadable music a sure sign that most of us are content with the “good enough” sound quality when it comes to hi-fi, like the cassette tape did 40 or so years before?

By: Vanessa Uy

Had Philips got it right back in 1963 when they decided to promote the cassette tape – a somewhat lo-fi speech-only recording medium – as a domestic prerecorded music format? Well, given everyone and their dog’s fascination and the indisputable popularity (commercial success?) of on-line digital music downloads on the Internet, it is now safe to say that the music industry probably achieved musical playback perfection – sound quality notwithstanding – back in 1963. Way before the introduction of Philips’ and Sony’s digital compact disc into the global commercial music market back in 1983 – a full 20-year head start.

Haying experienced first-hand comparison tests of a state-of-the-art (in sound quality terms?) a late 1980’s Sony Walkman to that of a 2007-vintage i-Pod. It is quite safe to say that when it comes to the musicality of the analog medium, our wiper-snapper digital sound engineers – who happen to be way older than me – are utterly clueless when it comes to ultimate sound quality. The only redeeming factor of an i-Pod music player is the sheer ease – if you are a trigger-happy private security contractor – to listen to Tori Amos’ Precious Things or Little Earthquakes while you mow down innocent Iraqi civilians with your 5.56mm squad automatic weapon.

Given that my hi-fi / audiophile acquaintances – who’s hearing I can personally trust – have lately admired the World-Music savvy of cerebrally-hip on-line music download sites like We7. I – more often than not – fall back to listening to “physical media” – like compact discs in order to find out how much of the sound quality has been decimated as it travels down through the Internet’s infrastructure. As one of my audio-buddies have the good fortune of acquiring Susana Baca’s Travestías album – in CD format, it has lately become our audiophile community’s version of an audio objet d’ art. As a standard to compare the degree of sound quality degradation that can occur with its We7 downloaded counterpart. The CD – for all intents and purposes had become our de facto version of the Six-Eye pressing of Miles Davis’ Kind of Blue LP.

While the small physical size and slow tape speed will always serve to limit the ultimate performance of the “lowly” cassette tape despite of improvements over the years. Like the use of exotic magnetic media – i.e. super Avilyn, high coercivity metal particle tape, ferrichrome etc. – or the employment of various Dolby noise reduction schemes like the B, C, and S variants. Not to mention the Dolby HX Pro or headroom extension to enable the “lowly” cassette tape record signals with a little more decibels that it supposed to achieve.

Though a handful of audiophile purist view the cassette tape as musically superior midrange wise when compared to downloaded digital music media, the consistency of cassette’s sound quality is another thing. While the sound quality of cassette tape will slowly – really slowly – degrade over time the more often it is played, we can always rely on the consistent sonic mediocrity of downloaded digital music. Looks like my 78-RPM shellac of Billie Holiday’s Strange Fruit could be sold on E-Bay at Harrier Jump Jet prices before I die.

Saturday, January 31, 2009

Is the BBC Sound the British Sound?

Praised by audiophiles and hi-fi enthusiasts around the world for it’s “upbeat” – i.e. pace, rhythm and timing oriented - sound, is the British Sound ultimately defined by the “dead” BBC sound?

By: Vanessa Uy

Maybe it’s because the UK has been making and marketing hi-fi kit for a longer period of time and in greater variety when compared to other nations. Or is it more likely that the UK had a “certain size and construction of there average living rooms” – i.e. medium-sized in global terms, wooden floored with a plaster on brick wall construction. Either way is the concept of the “British Sound” – which is characterized by an emphasis on pace, rhythm and timing – in other words a more upbeat sound in comparison to nations outside Europe, ultimately defined in the end by the “tonally dead” BBC Sound? Given that the concept of the British Sound can be defined by a single sentence containing the words: pace, rhythm, and timing while the concept behind the “Dead BBC Sound” has a somewhat “epic history”, the discussion on what is the BBC Sound warrants further discussion.

Even though the BBC – or the Beeb as it is affectionately called - was recently embroiled in a controversy when it’s principle of “journalistic neutrality” was challenged by its decision in refusing to air that politically charged Gaza Aid advert. The concept of tonal neutrality behind their famed BBC Sound is world renown by audiophiles and hi-fi enthusiasts. Sometimes commonly referred to as the “Tonally Dead BBC Sound” - which is meant as a term of endearment of course – can trace it’s origins in post-World War II Britain.

Beginning in the late 1940’s, the BBC’s Loudspeaker Research Department conducted serious studies of what was wrong with most commercially available speakers at that time. As it turned out, there was plenty. The concept of high-fidelity or hi-fi was nonexistent. Off-the-shelf commercially available speakers were not high-fidelity because an overwhelming majority of people played records through their radios. The luck few that had more serious sound systems typically made their own, good sound – back in the “good-old-days” - was rather a do-it-yourself affair. Open-baffle loudspeakers – those with drivers that were drilled into a plank of wood larger than the drive-units themselves - reigned supreme.

High-fidelity as a marketing concept – rather than the genuine article – came along at about the same time when Rock & Roll was born. Or when Elvis became a worldwide phenomenon as remembered by most people back then during the early to mid-1950’s, spurred in part by the introduction and latter popularity of the long-playing record after it was introduced in 1948. So did the practice of putting speaker drivers in closed cabinets.

The BBC started to gain interest in sound quality when the need arises to monitor the sound quality of their broadcast – especially their live concert broadcasts – using high-fidelity equipment that’s portable, thus making the BBC famous for their in-house designed minimonitors like the LS3/5A minimonitor and its licensed commercially manufactured variants. Even though it was the Quad ESL electrostatic loudspeakers and its related variants that was became “inexplicably” linked to the current definition of the BBC Sound. And the rest of the BBC Sound saga – as the saying goes – became a major part of the hi-fi history.

So what is the “Tonally Dead BBC Sound” and why do an overwhelmingly large number of audiophiles and hi-fi enthusiasts the world over liked it? Well, the BBC Sound is characterized by a sound quality that is accurate, pure, clear, and free of overt tonal coloration. Chances are that if you happen to be a professional musician who more-or-less uses a world-class recording studio as his or her 9 to 5 “office”, the audio equipment that is used so that you can hear yourself sing probably has this sound quality. Or just listen to the drums on Iron Maiden’s “The Number of the Beast Album” – assuming of course you have a “sufficiently neutral” domestic audio system.

What I like about commercially sold audio equipment designed around the British Sound / BBC Sound is that they have a very good price-performance ratio – i.e. very good bang for the buck, which is a very good example of that good old British sense of post-World War II frugality in practice, which is not bad by the way. My only reservations is that if you are lucky enough to own very-expensive – and very likely esoteric – audio equipment that can realistically play a very hardly struck ride cymbal. Then you might find those kinds of entry-level audio equipment – especially solid-state / transistorized ones - designed around the concept of the British / BBC Sound a bit dull and neutered.

A case in point is my own magical experience of listening to Veruca Salt’s “Loneliness is Worse” using a preamp whose brand-name starts with “Michell” – prized for displaying a “sense of the artist’s urgency” when playing tracks like these. You’ll probably start to notice in your side-by-side comparison that there’s this “lack of urgency” characteristic in entry-level solid-state equipment designed with the British Sound / BBC Sound in mind. But as it is of all things as it is in hi-fi, you can always get something better by spending a little bit more. Given that the BBC never fails to apologize to their worldwide audiences whenever their broadcasts are technically plagued – temporarily at least - by poor sound quality, then the BBC Sound is for all intents and purposes is the “literal” definition of the British Sound.