Posted by Pat [ 209.148.142.114 ] on April 11, 2004 at 00:18:19:
In Reply to: Re: ZUS and Seal Electronics DIY amplifier posted by Wayne Parham on April 10, 2004 at 04:27:55:
Building Randy Slone’s OPTI-MOS/ZUS 03/9/04 Amplifier’s
Let me start by telling you a little about my self, I am an automotive technician by trade, and just started with electronics as a hobby. I have only built one PCB project and got hooked (IR 12 relay control board I use for my theater lighting). It was time for me to look for anther project to build, when my brother in-law said why don’t you build an audio amplifier, I laughed at him and thought he was crazy! But then I got curios and started my research on the web. When I realized that it was possible to build my own audio amplifier,I furthered my research and found many different amplifier kits, from very simple ones, to more complicated ones. By this time I had my goals set, not just to build any ordinary audio amplifier, but to build ultimate amplifier, something I can use for my home theater system,that is better then I already have! In my year long research, I heard a lot of good things about Randy Slone and his OPTI-MOS amplifiers. I purchased one of his books (High Power Audio Construction manual) and decided to build one of his amplifiers, even thought it looked more complicated. People were comparing it to some major high end power amplifiers, and I had to hear it for my self. I finally ordered my two OTI-MOS amplifier modules and his auxiliary control board. When I received the parts I was blown away the quality of the parts, BIG heat sinks weighing in at one pound each, that’s were I new these were some serious amplifiers, so the construction began. I started with the auxiliary control board, which was a little hard at first because component placements are not marked on the PCB,but once you get started it’s not too bad. I completed and tested the auxiliary control board with no problems, and was ready to start on the amplifier modules. I found that the best way to start is to do your inventory and separate all the components into groups at the same time, this saves a lot of time. Assembling the amplifier modules were time consuming but pretty straight forward, I had no problems at all. By this time I had to start thinking about the power supply,and the enclosure, I had a five disk CD player that never worked well from brand new,so I gutted it out and modified the face plate and using it as the case for now,because my plan is two build a 4 or 5 channel amplifier. These amplifier modules are easy to incorporate into any enclosure,which is a good thing because I’m not too good with working with metal. Now it came down to the power supply, by this time Randy Slone had come out with his new low impedance power supply board that I seen on the ZUS audio web site, when I saw that board I had to have it, because it was a nice clean set up. So I finally got my power supply (800VA 50+50 transformer) and low impedance board with 80,000uf of capacitor reserve, now all I had to do was wire it up. The wiring didn’t take two long; by this time I was getting a little nervous, but that’s what it’s all about, getting that adrenalin flowing. Once the wiring was done all I had to do was to set the bias which consisted of measuring DC voltage between to clearly marked points on the PCB, and it was ready to rock!!!!!!! When I heard it for the first time it blow me away! This has to be the best sounding amp I ever heard!! It has excellent bass control and a wicked top end I am very pleased!!! I will post pictures as soon as I can figure it out! I am a newbie at this whole thing. One more thing did I mention it has power to spare!! It’s running two pairs of speakers (15” Cerwin Vega D9’s and energy C7’s) and it barley gets hot!
Pat Ciardullo
[ SolidState Forum ] [ Help ]