@zipost
Do you have the schematics of your Blue Circle 21 preamp? and what is the B+ voltage?
BTW, I also found a BC21.1 with outboard power supply on usaudiomart.
http://www.usaudiomart.com/details/649027319-blue_circle_211_tube_preamp_with_bcg31_power_supply_fre...
Do you have the schematics of your Blue Circle 21 preamp? and what is the B+ voltage?
BTW, I also found a BC21.1 with outboard power supply on usaudiomart.
http://www.usaudiomart.com/details/649027319-blue_circle_211_tube_preamp_with_bcg31_power_supply_fre...