[pftrvlr]

I had the Wooaudio 3 before, and did not like the flat sounding.

I sold the amp, but still have quite a few 6dj8 and 6as7 tubes left. Being wanting to put the tubes to good use, I built this DIY headphone amp. After two weeks tweak and listening, I'm glad that it sounds better than the Woo 3 that I can remember.

 

[pftrvlr]

The schematic is based on this one with slight change of component values

http://headwize.com/projects/showfil...aarde1_prj.htm

The output capacitors are Panasonic TSHA 470uf bypassed by Russian oil cap.

The PSU filter capacitor are 8 10uf MKP in parallel.

AC heater supply. Tried the DC, it is quieter than the AC at max volume. But the heat shut the 1084 regulator down pretty soon. I'm happy with the AC heater so far.

Currently I am using a Chinese 6N13P in place of 6as7. It is a good sounding tube. I am not missing the 5998 tube.

 

[Zigis]

I made this amp on test board few years before, then I have only cheap 32 ohm phones, don't like them, Morgan-Jones sound better. R5 and R6 go awfully hot.
Maybe today, with HD580 I thinking different.
Zigis.

 

[pftrvlr]

Yeah, it does not drive low z phone. And I like 6SN7 tube much better than 6AS7 regardless the topologies.

I use three larger resistors in parallel in place of R5/R6. Still they run hot.

 

[JadeEast]

pftrvlr

Could you answer a couple of questions about your build.

Did you make any other changes to the amp to use the 6sn7
and did you keep the 6dj8 half as the driver?

 

[pftrvlr]

Quote:

Originally Posted by JadeEast /img/forum/go_quote.gif pftrvlr Could you answer a couple of questions about your build. Did you make any other changes to the amp to use the 6sn7 and did you keep the 6dj8 half as the driver?

This amp is 6dj8-6as7. Except for some minor resistor/cap changes, it is pretty much the same as the one in Headwize. I did try putting a CCS plate load on the 6dj8, but the operating point drifted too far way. I might not have done it correctly.

When comparing with my 6sn7-6sn7 cathoed follower amp, the 6dj8-6as7 is still flat sounding, and lacking the snap and details.