Can Radioactivity Affect Your Hi - Fi?

When high-end audio manufacturers publicly profess the practice of aging the lead and silver components used in their products, is this a sign that there is truth about radioactivity – especially alpha particles – can affect sound quality?


By: Vanessa Uy


Ever since Audio Note publicly announced during the 1990’s that they practice aging the silver used in their most expensive tube-based power amplifier for 20 years, almost everyone keeping up with the trends in the hi-fi world instantly showed their skepticism. Especially when all of the silver that was mined during the previous 5,000 years or so was formed countless millions of years before – probably in the nuclear processes of the interior of our present Sun’s predecessor. But a “fortunate few” hi-fi enthusiasts who have a working knowledge of nuclear physics have also voiced their concerns whether the Weinberg - Salam Theory of Weak Interactions has an audible effect on an audio component’s sound quality in a negative way.

Given that the main purpose of aging silver and other metals is to wait out for the unstable radioisotopes present in this metals to decay into something more stable. And since these unstable radioisotopes emit alpha particles when they decay, thus causing interference with the electron flow that makes electronic devices function. Sometimes I wonder though if precious metal mining firms ever used nuclear devices to mine silver inadvertently contaminating the silver with strontium 90, which has a half-life of 29 years.

A case in point is Audio Note’s Ongaku Amplifier – famed for being one of the most expensive tube-based audio power amplifier in the world – is also famous for using silver that has been aged for 20 or more years in the critical components (audio signal processing paths) in it’s construction. Given that this particular amplifier’s price (manufacturer’s suggested retail price) has managed to stay within 250,000 US dollars for the past 13 years can be considered a “sensible” purchase compared to items of it’s ilk.

Pertaining to the silver used in the Audio Note Ongaku Amplifier, it is made up of medically pure silver. Using silver prices back in October 20, 2008 – the last time I checked – at US$ 9.50 an ounce (Troy ounce) or 9.50 dollars per 31.1035 grams in metric. The 9.3 kilograms of silver used in the amplifier costs US$ 2,850. Given that Audio Note aged the silver used in construction of the amp – probably to reduce stray alpha particles since our planet’s interior is naturally radioactive. And given this particular amplifier’s very, very excellent sound quality, the amp’s quarter of a million price tag seems that more reasonable – if you can afford it. Maybe alpha particles and other ionizing radiation can really affect the sound quality of your audio components.

But basing on what is currently known – in reality based on studies done in the 1990’s – vacuum tubes are not easily affected by ionizing radiation. This is the reason why during the Cold War that the Soviet Union seems cavalier when it comes to concerns about the electromagnetic pulse – or EMP – produced by a nuclear explosion “frying” transistorized / solid-state electronic equipment many miles away from the point of detonation. This is so since the Soviets still used vacuum tube-based technology until their collapse in 1991. Vacuum tubes are resistant to EMP onslaught and can be reset if they manage to shut down when an H – Bomb explodes near its vicinity.

So is the use of “aged” silver in vacuum tube-based amplifiers merely just “gilding the lily”? Well, it depends. Given the Audio Note Ongaku’s 250,000 dollar price tag, using 3 grand’s worth of 20 year old (or older) silver – probably sourced from the Hunt Brother’s silver hoard back in 1980 – can serve as a unique selling point for such a luxury item. But since vacuum tubes – especially ones designed during the 1920’s like the 300B – handle very robust signals compared to their transistor / solid-state counterparts, the engineering merits of such design considerations can become controversial. Since good engineering is based on the principle of doing something for a dollar when another person is doing the same thing for five.

Currently, the largest users of silver in the manufacture of “modern” electronic components are digital camera manufacturers. In practice though, audio components using silver tend to have a bright sound – i.e. boosted toward the high frequencies. Since vacuum tube-based amplifiers tend to sound warm in nature, then the use of silver – especially aged ones for consistency and just to be sure – tend to make tube amps sound more natural or balanced.