Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: brutzel on February 05, 2022, 08:46:26 am

Title: Snubber plate to screen, c46
Post by: brutzel on February 05, 2022, 08:46:26 am
Hello all,

there's a 22p cap from plate to screen on one EL34 of a 100W DSL2000 I have for inspection. What should this thing do?

The cap's solder joins looked corroded but not burnt, replaced it at the tube socket.

One of the EL34 was broken, a 1W 1Ohm bias resistor was burnt, soot al around. May this have anything to do with eachother?

Back to the 22pF ceramic snubber labelled C46
- it is only on one side of a symmetrically built machine
- I cannot find it on th 50W and 100W schematics
- it's broken

I suppose it might blend the pentode to a triode at radio frequencies, for less gain because of more Miller capacitance. But that's rather esoteric.

Can anybody shed light on this?
Why is it on one side only?
Title: Re: Snubber plate to screen, c46
Post by: pdf64 on February 05, 2022, 09:08:07 am
The cap may be fitted to endure unconditional stability, worst case circumstances and tolerance limits. Your amp may be fine without it, mostly  :icon_biggrin: