Adding pentode/triode/half power switch to tweed tremolux

[wcrankshaw]

I'm not sure what the proper name is for what I'm looking for, but most people seem to call them pentode/triode switches. It seems like nearly every new amp being made has a half power switch...15W to 7W for example. I've seen some loose descriptions of how to do this in a 5E3, but is this also possible in my 5G9? It's a little loud and I would love for it to have a more manageable top end for the house. Would it even sound good if this is possible?

[Chuck H]

Rather than go over it here... Google triode pentode switch. lot's of info.

[wcrankshaw]

Chuck, thanks. I'll do that (and have), but just wanted to come here to see if I could get some direct advice about my case. Seems to be lots of info regarding 5e3s...didn't know if there was anything I should watch out for or if it's a direct copy for the 5G9.

[JoeM]

Before you make a permanent modification, you might want to try wiring the output tubes in triode mode and see if you like the sound. I've tried this on some of my Fenders, and really didn't care for the sound. Seems to lack something, but of course everyone's preferences are different.

[Chuck H]

It does sound more muted. Probably due to triode mode, ideally, requiring a lower primary impedance. Switching OT's is a bit far to go. If you crank the amp I think triode operation in a pentode amp is fine. The peaky, pesky spikes seem to be subdued. Good thing. When wired on a switch I found myself using triode mode quite a lot. Getting used to it and liking it.

To address the OP's request:

[Regis]

I wired a P/T switch in a 5F1 I built from an old Voice of Music amp from the fifties. It was seriously underwhelming.