Mullard 20W Amp

[KLS]

Just wondering if anybody had tried to build the 20 watt amp in the "Mullard, Tube Circuits for Audio Amplifiers" book. I am thinking about building this but would like some insight as to the sound form someone who has built it.

Thanks
KLS

 

[Family_Dog]

Hi KLS,

There are 11 pages referring to this amplifier starting here:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=12023

And yes, some of us have built this, and enjoying it too! I'm listening to two of them as I type this.

-Eric

 

[shermanr]

The 5-20 amp is a very good design that sounds excellent.
My only advice would be to pay close attention to the mains transformer. There are not too many out there that will work well without some tweaking of the original PSU circuit topology.

The P782S Dynaco replacement transformer is probably as close as one can get to the best 5-20 Mains transformer. You can see this at the triode electronics web site. The PSU Choke is also not easy to find with 200 Ohms resistance at 10 H, 180 ma.

I am presently looking at ordering a technically exact Hammond custom transformer and choke for my 5-20's. If I do decide to order several you may just be in luck to buy them from me.

You can check out my 5-20 story at www.shermanaudio.com

Good luck...