[macm75]

This is certainly in phase 1 (yeah a messy phase 1 as you can see) but I thought I'd share a pic. For more info on the design go to...
http://www.audiodesignguide.com/my/stax_amp2.html

Like I said, this is a start and a lot more playing will be made. My plate chokes cause crazy hum problems so I have 100K resistors as the 6SL7 load. Notice what I had to do to remove magnetic interference on the coupling caps? Wrapped that caps (Jensen PIO) and extending wires 6x around with aluminum foil and grounded. I’ll try the same thing with the plate chokes. Mu metal will be a sure fire way to remove the hum but it’s costly. Anyway, with the resistors it's dead quiet and the gain is still more than adequate.

The upcoming phases I’ve be trying nice interstage transformers. As far as tubes, I'll be trying lots of DHT's I have laying around. I know this 6BX7 is very far from the end all and be all. Much to experiment with in the months ahead and I'll build a nice box for it when I'm ready.

My problem now is all I want to do is listen. This amp certainly does not sound like it looks I am new to Stax (I bought the SR-303's) and they are wonderful to say the least. I'm very amazed at the nuances, delicacy, and dynamics they possess. The music is so "there" that I can taste it. The soundstage is practically psychedelic the way the music images in my head.

Anyway, it's only been running for a few days now and hopefully I'll have even more positive news in the months ahead.

A few more pics if interested...
http://s143.photobucket.com/albums/r...Stax_Amp_1.jpg
http://s143.photobucket.com/albums/r...Stax_Amp_2.jpg
http://s143.photobucket.com/albums/r...Stax_Amp_4.jpg

 

[[AK]Zip]

Good job! I was thinking about building it for fun. I might still go through with it.

-Alex-

 

[picklgreen]

Wow! Very nice!

 

[tyre]

Just curious, how close is the bias supply to 580V?

 

[macm75]

I'm at 570V. I got it close and just left it there. I'll try to nail 580V later and see if it makes a diff - my guess is no. My voltage divider is different because I used a 700CT mains transformer.

 

[krmathis]

Good job! I envy anyone with the knowledge to put together an amplifier from scratch, and make it work as expected.