HRS

July 1, 2008

Gilbert Yeung is a sort of audio iconoclast whose products challenge conventional wisdom, and seem to create markets where there were none before. For instance, his Pinkie Project preamplifier uses massive capacitor banks much like batteries -- it can run on a single charge for over 50 hours. As if that weren’t surprising enough, how Yeung then charges the Pinkie is even more original: anything that can output 12-16V DC can be used. He uses a solar panel, but a car battery, a windmill -- even a car dashboard’s 12V cigarette-lighter socket -- will work. In Yeung’s words, he’s "off the grid." And maybe off his rocker.

As I wrote this, Yeung was readying the launch of a series of all-solid-state preamplifiers based on the Pinkie Project, and a new line of power amps based on that circuit design. The new preamp line begins with a base model; the buyer can then upgrade that base unit with plug-in Capacitor Packs. As capacitance is added, sound quality and length of operating time increase. The base preamp model is the BC109 ($3695 USD), which can be upgraded with the Capacitor Pack 1, or CP1 ($2995), and then the CP2 ($4995). The BC109 can also be purchased with the CP1 or both upgrades already installed, as the BC109 CP1 ($6690) or BC109 CP2 ($11,685). The new power-amp line begins with the BC108 ($19,995), to be followed later by three slightly scaled-down models: the BC106, BC104, and BC102 (prices to be announced). These will be higher-powered amplifiers than have typically been seen from Blue Circle Audio.

With the announcement of these new lines, I thought it would be a good time to ask Yeung a few questions about his unique design strategy. One of the most obvious things to be noted from a perusal of the product descriptions at www.bluecircle.com is that a great deal of importance is placed on the components’ power supplies. Amplifiers, preamplifiers, D/A converters -- all have supplies that look as if they could run a small nuclear reactor. I asked Yeung to explain why the power supply is so critical, specifically for power amplifiers:

"The power supply, as far as I’m concerned, is the most important part of the entire amp. The speaker sees the output impedance of an amp, and that output impedance is directly related to the output impedance of the power supply. Without the low output impedance of a power supply to back it up it doesn’t matter how low the theoretical output impedance of an amp’s output devices is -- it will not support the musical demands placed on it. Every time there’s a demanding musical passage, it draws current from the amp. If the power supply can’t hold up all the way through that demanding passage, it will collapse. That’s one of the main reasons I pay so much attention to power-supply design, and pack in as much capacitance as cost and other factors will allow."

I asked Yeung to explain more about how generous amounts of power-supply capacitance benefit an amplifier, both technically and sonically.

"It all starts at the wall. AC power coming from the wall outlet is good enough for most purposes. We have 120V/60Hz in North America and 240V/50Hz in other places in the world. It is an alternating waveform, supposedly. These days, it is very difficult to get clean power. Some audiophiles use external power-line filters and conditioners. Internal AC line filters can also be incorporated....(read more)

Opinion | Equipment | Features | TWBAS | Music | Letters | SoundStage! Network

All contents copyright © Schneider Publishing Inc., all rights reserved.
Any reproduction, without permission, is prohibited.

Ultra Audio is part of the SoundStage! Network.
A world of websites and publications for audio, video, music and movie enthusiasts.