Tested both regs, are OK, finally at PS used only 10R at positive rail between the two 15.000uF caps.
4P1L is notoriously sensitive to vibration.
Sometimes double damping necessary:
socket with vibration damping
to high/er/ mass subplate 
and occasionally this subplate also isolated from plate/base board.
Not sure these rubber dampers help much with microphonics. I guess much of the noise pickup is via sound/air. Also the small and stiff rubber pieces will not dissipate a lot of the mechanical noise.
Do you have any specs on the rubber dampers you used?
You could test the effectiveness like so: https://www.diyaudio.com/community/...stat-headphone-amp-osdeha.407679/post-7588550
You could test the effectiveness like so: https://www.diyaudio.com/community/...stat-headphone-amp-osdeha.407679/post-7588550
You wrote, that PT is 60VA 18VAC. This is more than enough for filament biased 4P1L (0.65A current).
With this parameters the raw output (C-CMC-C-L-C in my practice) about 20-21V.
Please sketch the LT PSU.
With this parameters the raw output (C-CMC-C-L-C in my practice) about 20-21V.
Please sketch the LT PSU.
If the PT is 18VAC it's working.
5.88V headroom is just enough for R.C.
If you want more headroom, decrease 10R to 8R.
Are you sure, that R.C. all component is OK?
Rset is 3R3//3R3.
If you tested the raw supply without R.C, the dummy load resistor value must be 27R.
17.7V/27R= 0.655A
5.88V headroom is just enough for R.C.
If you want more headroom, decrease 10R to 8R.
Are you sure, that R.C. all component is OK?
Rset is 3R3//3R3.
If you tested the raw supply without R.C, the dummy load resistor value must be 27R.
17.7V/27R= 0.655A
Since the raw DC supply is symmetric (not grounded), you might want to consider adding a second resistor between C1 and C2 on your "Null" side.
