Friday, February 29, 2008

Romancing Black Gate Capacitors

What is it about Black Gate capacitors that installing them in your audio amplifier’s power supply always result in a dramatic improvement in sound quality, or is the perceived improvement just in our heads (and ears) as the current wisdom of meter reading audio engineers attest?

By: Vanessa Uy

Anyone who practices DIY (Do it Yourself) hi-fi surely have come across with one of the audioworld’s most revered electrical components – Black Gate capacitors. Often used as power - supply filtering capacitors in many high – end power audio power amplifiers. Black Gate capacitors especially the “lower cost” Japanese versions manufactured by Rubicon had since become available - as replacement parts sold in electronic parts retail supply stores - to the DIY hi-fi hobbyist. And since their use have sparked the debate between subjective and objective ways of assessing the sound quality of an audio power amplifier. But as hi-fi enthusiasts later knew, other “sections” of the audio chain like the preamplifier / signal controller’s power supply section of a typical audio system. And even the power supply of the CD / DVD or other front - end player will benefit in improved sound quality when their "stock" power supply capacitors are replaced / augmented with Black Gates. But before we proceed further, here’s a brief primer on what are Black Gate capacitors.

Black Gate capacitors are a premium grade of electrolytic polarized capacitors specially constructed as to have a much lower effective series resistance (ESR) or impedance than cheaper electrolytic capacitors. Probably designed and marketed during the latter half of the 1970’s, Black Gate capacitors were probably built by their creators for use in high frequency switching mode power supplies due to their low ESR. But this didn’t deter audiophiles, DIY hi-fi enthusiasts and tweakers from using them on the linear power supplies that convert the ordinary 60 Hz AC household current into the DC used to power audio equipment because it made them sound good. During the late 1970’s and throughout the 1980’s, almost all Black Gate capacitors were manufactured by a Japanese electrical and electronic manufacturing concern called Rubicon. Rubicon became explicitly linked with these capacitors because at the time – especially in the 1970’s – Japan was still a “low wage” country which was a bit later replaced by Hong Kong and later Taiwan as the low cost production capital of the world. Because Rubicon Black Gate capacitors were relatively cheap, hi-fi enthusiasts freely experimented with them without the feel of burning their wallet if they accidentally “cooked” one. Thus Rubicon Black Gates became the raison d’ĂȘtre of DIY hi-fi.

But by June 1995, Rubicon – the Japanese manufacturer of Black Gate capacitors, has ceased production of the famed premium grade electrolytic capacitors. The move was perceived by hi-fi enthusiasts as being similar to Porsche quitting the manufacture of the 911 because it can’t make them as expensive as Ferrari’s megabuck sports cars. Keith Parker of Rubicon, London, said: “the Black Gates were a 20 - year - old design (in 1995) unsuitable for mass production, so they had to be hand assembled. Many of our newer electrolytics such as PS2, YXB, and YXF perform every bit as well when used properly”. In my experience so far, Rubicon’s PS2, YXB, and YXF electrolytic capacitors are often used in mid-priced (US$500 – US$1,000) DACs (Digital to Analogue Converters) manufactured in 1995 and beyond. Despite of Rubicon ceasing production of Black Gate capacitors, Jelmax, who own the Black Gate design, still manufactures the capacitors albeit at prices much steeper than the Japanese Rubicon versions. These pricier version of Black Gates were often used by Audionote one of the most respected names in tube based audio amplifiers.

In practice, hooking – up Black Gates to your system really does wonders no matter what kind of music you like. I mostly listen to guitar based heavy metal music at unamplified drum kit sound levels, and believe me, they do tend to sound as if the musicians are in front of you. Poorer recordings are redeemed by making them “listenable” over prolonged periods and can even make you conclude that this particular sound is what probably the record engineer / producer (or the artist) intends it to sound. Black Gate capacitors are probably the only tweak you need that makes listening to music more pleasurable without taking psychotropic drugs or anything similar. The bad news is if you bought hundreds of dollars of audio analyzing equipment like the latest ones by Hewlett Packard which can be connected to your Windows Compatible home Personal Computer, the output waveform of your amp remains the same before or after tweaks despite what your ears tell you. Believe me, existing audio analyzing equipment like the one I just described can be “stone deaf” when it comes to sound quality – unless you’re looking for “rogue submarines”. So better spend that money on other stuff like CDs, or give it to charity if it is really burning a hole in your pocket.