Fizzy,crackly distortion from speakers on 36watt lite
Posted: Tue 03/27/12 10:36 am
I built a 36 watt lite and it has some nasty trailing distortion when cranked up a bit.It's not a cold solder joint or biasing issue and all the usual suspects like tubes and such have been eliminated.
The plate dissipation is 13 watts.
It sounds like an oscillation and it does lessen considerably when I upped the grid stopper resistors from 8.2k to 220k but it's still there.I could go larger on the grid stoppers but the highs are suffering from the increased stopper values.
Is this the dreaded EL84 fizz problem?
I'm using a separate pair of cathode resistors and caps for each pair of tubes so I'm wondering about the Paul Ruby fix and how one would implement it with separate R/C's ?
Any insight would be appreciated.I have built quite a few 36 watters and this is the first one with this issue.
The plate dissipation is 13 watts.
It sounds like an oscillation and it does lessen considerably when I upped the grid stopper resistors from 8.2k to 220k but it's still there.I could go larger on the grid stoppers but the highs are suffering from the increased stopper values.
Is this the dreaded EL84 fizz problem?
I'm using a separate pair of cathode resistors and caps for each pair of tubes so I'm wondering about the Paul Ruby fix and how one would implement it with separate R/C's ?
Any insight would be appreciated.I have built quite a few 36 watters and this is the first one with this issue.