cleverdick
Active Member
In my quest to cure a noisy RIAA stage, I did discover a fractured joint at D401 on the so-called EQ Sheet. (PITA to get to, mind!) Now, in this case, somebody before me had fitted a 330R, 5W resistor in the supply line - non-original and not shown on the schematic. Off-load the supply does measure 51V, as it should. (Haven't measured on-load, nor do I know what current the phono stage draws.) Now, assuming a perfect voltage source and a token 0.6V drop across D401, this leaves C421 sitting at a theoretical 50.4V. Given that it's a 50V rated cap, this makes me a little uneasy. I'm tempted to up to 63V - but I'd like to know if anyone else has had problems in this area. No sign of bulging or distress.