Into the world of Audio Amplifiers

What if I told you that my current employment has everything to do with my love of multimedia systems and most specifically my deep interest in audio amplifiers.

I remember as a kid looking in awe of my Dad’s home stereo, a JVC JR-S600, it was beautiful with its blue glow and heavy tuner shuttle.

When I was growing up I visited a hi-fi store in the Seattle area and was drawn to a room with a movie theater in it, I sat down and listened to the demo and I never forgot it.

It set off a quest to attempt to recreate what I had heard that one day, and that sound eluded me until I discovered the magic of high power audio amplifiers.

When I built my CRT movie theater in my basement I did a ton of research into amplifiers and ended up buying a fantastic amplifier and subwoofer and properly calibrated my audio to the room.

I could have never prepared myself to what I heard after I was done, not only had I met what I heard in that hi-fi store, but I  exceeded it.

I could hear things in music I had never heard before buried inside the music and soundtracks that was buried in the mud.

I listened to every CD I owned and watched every movie as well, it was absolutely incredible.

 

Since I had fixed my CRT projector after failing to fix a DWIN CRT projector, I found a very nice audio receiver and attempted to fix that, and I failed to do that.

I would take a several year break between that failed amp fix and when I began to really dig into the world of audio amplifier design. When I was at Xbox, I decided to dig into audio amplifiers properly.

So I did like I seemly always tend to do, I went out and found every book on audio amplifier design that I could find current and past. I learned so much that I started to ask around the company to see if anyone around did any sort of audio amp design of any kind.

Sadly there wasn’t anyone. Since I knew enough about audio amps to be dangerous I was given the task of being the audio test lead for a project at work and I gathered all the material to begin testing and then I got hit by a really huge layoff at the company and had to leave.

At that time just before this I started buying some guitar amplifiers and actually began to fix them! I think it was a natural progression into amplifiers from learning as much as I could about them into fixing guitar pedals and then general audio equipment.. it was only a matter of time.

 

I moved on to fixing just about any amplifier I could get my hands on. If it was around 40 dollars on ebay and broken during this time I was probably just about guaranteed that I ended up buying it. I am not sure how many amplifiers I fixed during this first part of studying amplifiers. When I started slowing down on fixing amplifiers I started building them, mostly chip amps to test my ability to properly ground and layout audio boards. It was during this time I got hired on at a really great professional audio company and got the reputation of fixing amplifiers there too. I enjoyed fixing and restoring old amps and helping others I work with fix their own cool vintage audio equipment. I still really enjoy both restoring and fixing amps and building them too.

 

Here are some examples of amplifiers I have fixed:

Here is an Cambridge Audio A3i amplifier I fixed and modified, I am actually currently listening to it while I am writing this. Its not in the most cosmetically beautiful shape but it sounds amazing!

Here is a Marshall Valvetronix Amplifier that I got from Ebay and Fixed (new capacitors and new chip amps for the solid state section), and the guitar I got traded for it. I love that guitar so it was a great trade.

 

Here is a fender LTB PA amplifier that I fixed and sold, it was a pretty fast fix and sounded good.

Here is the my Onkyo receiver that used to run my home theater, I actually stopped getting audio. It ended up needing a new relay so I replaced the broken one and replaced the other channels relays as a preventive measure and rebiased. It is currently hooked up to my TV at home providing entertainment again.

Here is a Crest Audio CKV100 professional PA amplifier. When I got it is was locking up with those beautiful red protect LEDs. I tracked down the problem to a module that is use to detect system state. I fixed that part, and rebiased, sounds great!!

Here was an Onkyo receiver I bought broken on Ebay that wouldn’t even turn on. It turned out to be a few bad output driver FETs. I replaced them and the current resistors, rebiased and was back in business.

This B&O Beomaster captured my imagination when I found it in a local salvage, I probably did the most to get this working of any amplifier.  I replaced all the old electrolytic capacitors, hunted down proper indicator lightbulbs, a new balance slider potentiometer and fully serviced it. I ended up selling this unit on ebay and the person that got it absolutely loves it. It was a lot of fun to bring this one back to life and it sounds really great.

 

There are more that I fixed that I didn’t take photos of and of course I get to work with audio amps all day in my current position 🙂

 

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