The Peter Daniel tribute amp

[tiroth]

Peter,

I've been very impressed with your elegant, austere designs. This is my rendition of your acrylic GC; I took what I felt to be the general feel from this amp, rather attempting a carbon copy. I am still struggling to accomplish in weeks what you can in a few days. 😉

 

[tiroth]

Back

 

[tiroth]

insides

 

[tiroth]

Here is something slightly more original. I am still deciding between black and natural for the vents. These are good for a full 40-45W, although I intend to use them as tweeter amps and use no more than 8-10W.

 

[tiroth]

I need a better camera. 😉 The monoblocks are transformer-coupled. There is no input coupling cap, although there is a zobel network on the transformer secondary.

 

[tiroth]

Here is an ugly little amp that I built as a center channel monoblock. It sits out of sight and gets the job done; I did use good parts for the internals. Most of these amps use Panasonic FC supply caps, Holco (NOS) resistors, and Alps pots. I did some experimenting with Dales. The blue coupling caps are ERO MKP1845...very nice.

 

[tiroth]

And finally, this was my first GC, built to test the chip amp waters. It uses junkbox parts and does not sound as good as the others. 🙁 I was impressed enough though to try to improve the design.

This makes a nice computer amp at 15W/channel.

 

[Da5id4Vz]

Coincidence or Bizarro world.

Interesting,
Your first amp has a wooden case.
Peter’s latest amp, also wood. Hmmmm.....

What kind of input transformer did you use in the MB-GC? Is that a motorized pot next to it?

Nice work. Interesting progression.

-Dave

 

[Steve Eddy]

I need a better camera. 😉 The monoblocks are transformer-coupled. There is no input coupling cap, although there is a zobel network on the transformer secondary.

What is that, a power transformer with the dual primaries wired up as primary and secondary windings?

By the way, nice work!

se

 

[moe29]

i like Natural for your vents choice... looks very clean.

superb work 🙂

 

[Nuuk]

Nice work Tiroth. Would you like your efforts included in the Decibel Dungeon Gainclone Gallery?

BTW - I prefer the black vents 😉

 

[tiroth]

Thanks for the compliments! To answer some questions, yes, I used leftover motorized pots because I have a number on hand.

I did use a Talema power transformer (115:44 nominal) in the monoblocks which is almost exactly 2:1 in the turns ratio. Although this may cause great dismay among some people 😉 this transformer is really quite nice for the application. It is flat from 20Hz-30,000+Hz, although there is some distortion at low frequencies...roughly four times that of a Jensen transformer I believe. By 1kHz though distortion is below -100dB, making it perfect here. (There was some ringing in the 100-150kHz band but that was easy enough to damp)

As a bonus, the monoblocks maintain absolute phase thanks to the transformers.

Nuuk, please feel free to include whatever you want. I think the idea of a gallery is really nice. Thanks!

 

[Peter Daniel]

Nice implementation😉

Have you thought about shielding the amp: top and bottom covers? Originally I wanted to make it open, but the interferences (even signs of oscillating) were so strong, that I had to remove coupling caps (as they picked quite a lot) and install metal mesh on top with a ground attached. Since most of my amp is done from acrylic, I had to also run another wire to ground the pot. I also noticed that best sound is achieved with a single cone in front and acrylic-rubber footing at the back.

 

[tiroth]

Thanks Peter! I have been considering putting some type of cover on this amp....I have had no problems with oscillation but the noise floor is definitely higher than the fully-enclosed amps. There is a metal subchassis in my amp and the inputs/caps themselves rest partially under the grounded body of the pot, so I think I avoid some noise that way.

Thanks for the suggestion.