Add gain before or after the phase splitter?

[qq]

Aside from fixes/adjustments to this, maybe the next thing to try is FET source followers to drive the output grids. I'm sure the neigbors will appreciate the increased volume.

 

[ray_moth]

Hi qq,

Glad you've been making progress. How does it sound?

I expect you'll be able to improve it no end with those sf drivers. If you need any advice on which MOSFETs to choose or how to set them up, there are several knowledgable members here (but not me, I'm a beginner with those).

 

[qq]

It sounds pretty good to me. I've been using it pretty much exclusively since getting it sorted out and it regularly impresses me. I did some side-by-side taste tests with my old consumer stereo and I certainly don't notice any deficiencies in the tube amp by comparison. Whether I like mine better because I built it or because it's just "better" could be debated endlessly, but I like it. I'll definitely say it's more than good enough to hear the deficiencies of mp3 compared to CD or vinyl.

I just did a PC board layout of the input and driver portion today, so that (hopefully) I'll have a known working setup of the current state for reference during further experiments. If it passes the smoke test and anyone's interested, I can put up the cad files and stuff.

I believe SY might be the resident authority on FET source follower drivers? There were already a few good links posted on the subject earlier in this thread...

 

[nigelwright7557]

I do wonder about power supply interaction with all the different dropping resistors... starting with 400v, down to 210 for the screen, 300 for the 6sn7, somewhat less for the 12ax7, etc... None of it is exactly well regulated

http://mexico.limpoc.com/~eric/test.jpg

eric

I have just finished a pre amp mixer using the 12AX7 and found I needed more like 100uF on the anodes to get rid of hum.

 

[ray_moth]

I believe SY might be the resident authority on FET source follower drivers? There were already a few good links posted on the subject earlier in this thread...

I'm sure SY knows all about it but there are others, too, who know this sort of stuff. At the risk of omitting to mention some worthy members, the others who come immediately to mind are Tubelab, Eli, Wavebourn, Yves and Miles.