I have an Infinity DSP Switching Amplifier, this was the first Hi-Fi digital amp, they were high end and few were built in the late 70’s iirc less than 200. Schematics were never public, neither any service manual. It was working OK until few weeks ago, well almost perfect, it produced a low humming sound when no input was fed but it was hard to hear, but one day I could not get any more power. Knowing the age, design and no schematics I was very skeptical that I could ever have it running again. I live not too far from Tucson so I searched for places that repair High End Audio and after visiting few places one of them told me to go to the Hi-Fi store.
John (owner), took his time to find out the initial problem (no power) and also told me that he found another area that he could repair to get the amp back to “normal”.
Today I took the amplifier home, price was more than reasonable, I just hooked it into the system and not only works but also the humming that I noticed before the no-power event (btw I never told John about it, he found it) is gone.
You can not believe how happy I am, not only this great and unique amp working again (kind of a collector’s piece) but the cost was so minimal.
John works in any piece of Hi-Fi.
If you ever read this comment John, honestly THANK YOU.