Awesome

Shall we try again!!!

The Pass Son of the Zen SingleEnded Mosfet amplifier... Succesor of the Pass Zen. Words to describe this amplifier are hard to come by. I built it as my High School Senior Project. It cost me in the neigborhood of $600-$700. This may sound like a lot, however if you have ever heard one of their production amps, you will understand. (The production amps start at $3000)

As I said I am not too gifted at coming up with words to describe it, I will quote my mentor who works at a local stereo shop:(the only good one in town)

'Wow it works!' Refering to craftsmanship.
'Wow it doesn't sound bad either'
They then began to dissasemble it when I said, "Why don't you plug it into some speakers that are placed correctly (instead of just sitting at the side of the room)"
It was then plugged into a pair of Paradigm Studio 100's with a Marantz cd 67se cd player.

'Wow! That thing sounds incredible'

And at later dates, when I spoke of my amp, they would pipe in 'And it sounds awesome too'

So there are the words that sum it up. The sound is awesome.

Now for the bad part...

Building the SOZ was a bit of a chore, requiring much time and a bit of money. I got a bit of help from Nelson Pass himself (through e-mail). The overall weight of the amplifier exceeds 100lbs. All this for a 30x2 amplifier. It generates enough heat to heat some houses (in alaska) for the winter. On my amplifier I have about 35 square feet of heat sink surface area, and the air coming off the heatsinks is still 110 degrees (F). I also melted several parts
(inductors, binding posts, 1 speaker...(binding post short...40v DC across speaker...unlimited current...no fuse blow in powersupply))

But in the end it is worth it. It sounds incredible.

If you plan to build one, here is a summary of my amplifier:

Power output: 30x2 rms
Input: Balanced XLR
Output: 5 way binding Post
Heatsinking: 35 SQ ft. AL

Powersupply:
Wall->2000VA Variac->1500VA Torroidal Transformer->40A Rectifier Diodes->2x 100v 36,000mf Caps->14g Inductors->2x 100v 36,000mf Caps->Amp

If you plan to build one, it is much cheaper to find your caps at a surplus electronics supplier. In mine I have 24, 50v 12,000mf caps wired in series pairs and parralled for a 36,000mf 100v bank.

System Info:
Tested on At home
Speaker Pardgm Std 100 Dynaudio Aries
Spkr Cbl Pheonix Bi-wire Audioquest
Inter DH-Labs
CDP Marantz CD-67se

If you plan to build one, someday I will get around to putting pictures and stuff up on my website at: 'chris.erickson.homepage.com'

Good luck and happy amp building.

Since audio review cut out the center of my review, here i post the missing part:

'Wow it works!' 2000VA Variac->1500VA Torroidal Transformer->40A Rectifier Diodes->2x 100v 36,000mf Caps->14g Inductors->2x 100v 36,000mf Caps->Amp

Incredible sound

Incredible Heat
Incredible Weight

The Pass Son of the Zen SingleEnded Mosfet amplifier... Succesor of the Pass Zen. Words to describe this amplifier are hard to come by. I built it as my High School Senior Project. It cost me in the neigborhood of $600-$700. This may sound like a lot, however if you have ever heard one of their production amps, you will understand. (The production amps start at $3000)

As I said I am not too gifted at coming up with words to describe it, I will quote my mentor who works at a local stereo shop:(the only good one in town)

'Wow it works!' 2000VA Variac->1500VA Torroidal Transformer->40A Rectifier Diodes->2x 100v 36,000mf Caps->14g Inductors->2x 100v 36,000mf Caps->Amp

If you plan to build one, it is much cheaper to find your caps at a surplus electronics supplier. In mine I have 24, 50v 12,000mf caps wired in series pairs and parralled for a 36,000mf 100v bank.

System Info:
Tested on At home
Speaker Pardgm Std 100 Dynaudio Aries
Spkr Cbl Pheonix Bi-wire Audioquest
Inter DH-Labs
CDP Marantz CD-67se

If you plan to build one, someday I will get around to putting pictures and stuff up on my website at: 'chris.erickson.homepage.com'

Good luck and happy amp building.

Similar Products Used:

Listned to Aleph 5