snowman_al
pfm Member
Does anybody know the real-world operating voltages for C3 and C5 please? From the circuit diagram it seems C3 would be 160V max, but nothing is there for C5. I have 0.1uF 400V sets and 200V sets of the K40Y-9 Russian paper in oil types, and would prefer to use the 200V ones if possible as they’re less bulky, but wasn’t sure if the voltage rating was a tad too low. Cheers.
Real world, Leak used 350 volt types originally, so use the 400 volt ones you have. There is room.
C3 'sees' more than 260 volts before the EL84s start to conduct fully and pull the HT down. Then it depends on the ECC83 you have in V1. Expect more than the diagram voltage with modern digital meters - you could well measure 200+ volts.
C5 max will be somewhere near 30 volts (V2 cathode voltages at 37 off diagram) so actually could be lower voltage.
Just measured mine, C3 202 volts (Mullard ECC83), 218 volts (Sovtek 12AX7LPS) with ref to chassis. So 200 volt caps would be just good enough once all the valves are conducting...
C3 measures about 28 volts the instant you put the meter on it and falls to 20 due to the load of my meter.
Cross posts, I was busy with my meter...