GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Melquiades Amplifier
In the Thread: Bias help

Post Subject: Melquiades debuggingPosted by DA on: 8/19/2013

Well two power supply's ready and one full range amp hooked up.Nothing blew up so that's good!

1) output stage 200mA /187V

2) driver stage 205v (test point A) and -4.3v bais

3)setting 0.000v on input is ok but not stable,some DC drift

4) bais lines are low at around 175v (point L ) and 146v - 147v ( point C and D ). The power transformer for bais line puts out only 420 v for some reason and not 440v. at this setting gas tubes draw only 5.5 mA current .

5) Filament voltage is also low at 5.9v . Transformer rated for 6.3 v / 10 A .driver and output connected in parallel ( 6C33C in parallel heater connection )

Any ideas are well come especially with bais lines...I need at least 20v more....

Rerurn to Romy the Cat's Site