Hello!

Below I have included three jpeg's and pdf pictures of the Zen Amp.I built these units about 2 years ago, and they are still working every day.

The first picture is four Zen amps using the constant current source. The amplifier and constant current source MOSFET are on the same heat sink. Each heat sink is about 8 inches wide, 7.5 inches tall, and 2.5 inches deep. I am running a dual mono configuration shown here. I took a scope and a 5 ohm, 50 watt power resistor and connected it to the output.

I got about 12.5 volts peak-to-peak output before slight clipping. So the power output is: ((12.5)*(12.5))*(.707)/5 = 22 watts.

The power supply is in the picture on left. This is interesting. I had a diffcult time finding this transformer but I'm glad I did. It is rated at 900 VA.

The filter cap is a Sprague unit I found at a flee market. It is rated at 40WDC 120,000 ufd. Luckly the guy had three. I bought them all! :-)

I put a thermister and a fuse on the AC side of the transformer. The bridge rectifier needs to be heat sinked as shown here.

The last jpeg  is a close up of each "plate" I decided to do point-to-point wiring since this is a simply circuit. I used mica insullators under each MOSFET. I used 4-40 machine screws to fasten the transistors and the little solder points or lugs.

All wiring is done with teflon insulated silver wiring I found at a surplus electronics outlet. So far I have built eight of these plates. I now run a bi-amp setup. I also built two Zen preamps not shown here.

Now for the sound. I have tested and listened to many commercial grade amplifiers. Nothing comes close to the detail you get from this amplifier. I can't put my finger on it but it is by far the best sound amplifier I have ever heard.

Several of my friends in the audio hobby have heard my setup and are just amazed at the sound. So much so that they are now building their own Zen amplifiers. Even friends of mine that are not into the hobby are impressed.

I spent a lot of time and effort building these and think it was worth it. I can never go back to listening to anything else. Single ended class A is the only way to go. I want to thank Nelson Pass for his time and effort to lay this all out on a web page. My understanding of amplifiers and circuit design have been improved. I look forward to any new designs Nelson Pass comes out with. It makes this hobby very enjoyable to me. Please write me if you have any questions.

Regards,

Fred