6J5 Single stage UTC A-25 Output
Very Simple 6J5 single stage!
6J5 is half 6SN7. Sure different pin-out and 6J5 is a Single Triode.
It sound very different with my older Marantz 7. Sound warm but detail and thick! Strong music taste and tube taste. Very confortable. Finally, I found A-25 do not sound good on high current. Then I reduce it from 7.5mA down to 3.5mA. It sound more details and clean. But, that is not linear as in higher current. So, finally, I modify this AMP to a PSU of my newer EC88 AMP.
That is a simple AMP and excellent sound. I will re-build it some day.