2203 with extra gain stage - still have a spare triode, what to do?

[HTH]

ok, so some of you may remember my recent thread about installing a Mercury Magnetics OT in this 2203, adding an extra gain stage into the front end and getting instability probelms.

Well, I've come a long way in the project now and the amp is stable and is sounding 95% 'there'.

I've got a spare triode doing nothing, what do you suggest I use it for?

I've got all the gain I'll ever need, but I suppose it could be used to refine that extra gain stage. What about this...

extra gain stage >> CF >> existing 2203 preamp

anyone??? (or better ideas).

[Satamax]

Active tone control?

[dai h.]

rent it out to a metalhead

[HTH]

active tone control - nah, not my thing
metalhead - I am one, so no dice there

any views of setting it up as a CF running into the existing 2203 preamp?

I know that when I built a stripped down SLO100 I only used one CF and the tone was more aggressive than if I'd used the two CFs. I'm thinking that this could work out for me now too.

OR, just parallel the two triodes and be done with it (though that seems a bit of a waste).

[Don Moose]

just parallel the two triodes and be done with it (though that seems a bit of a waste).

I seem to remember something about that reducing noise. And then, don't you need to halve the Rp and Rk and double the Ck to keep it all matched?

[dai h.]

Matchless seems to like doing that (looking at their schematics). Also the Mojave Peacemaker (basically a Marshall) paralleled the input stage tube IIRC.

[Tobacco Soup]

active tone control - nah, not my thing
metalhead - I am one, so no dice there

any views of setting it up as a CF running into the existing 2203 preamp?

I know that when I built a stripped down SLO100 I only used one CF and the tone was more aggressive than if I'd used the two CFs. I'm thinking that this could work out for me now too.

OR, just parallel the two triodes and be done with it (though that seems a bit of a waste).

You could parallel the very first stage and get a little more gain, and a little 'thicker' sound (I did this to a pair of stages in a Plexi-ish clone and the clean sound was just fantastic). YMMV.

[Ben N]

(a) Turn one of your stages (1st?) into a cascode?
(b)Rewire the socket for a 9-pin pentode-voila, no leftover triode!

I know that you have more than enough gain already, but either of the above might be useful for a semiclean/vintage-crunchy option (you know, for ballads ;]) with a reduced number of stages.

[HTH]

(a) Turn one of your stages (1st?) into a cascode?
(b)Rewire the socket for a 9-pin pentode-voila, no leftover triode!

I know that you have more than enough gain already, but either of the above might be useful for a semiclean/vintage-crunchy option (you know, for ballads ;]) with a reduced number of stages.

what's a ballad? - you can see the devil horns on my avator right?

thanks for the input everyone, think I'll just parallel the triodes in lieu of any better ideas. I did this on my AC20 and it sounds great.

[Satamax]

(a) Turn one of your stages (1st?) into a cascode?
(b)Rewire the socket for a 9-pin pentode-voila, no leftover triode!

I know that you have more than enough gain already, but either of the above might be useful for a semiclean/vintage-crunchy option (you know, for ballads ;]) with a reduced number of stages.

Cascode, that's a good idea

[dai h.]

IIRC quite a while back Bruce had an idea of having paralleled triodes but setting them up differently (diff. cathode bypass?--which I guess makes for a more interesting outcome?). Might be in the archives.

[tubeswell]

I vote for CF in front of the tone stack cos it will make the tone controls work better, cos of the minimal impedance/buffer thing that goes on in CF stage.

[HTH]

I vote for CF in front of the tone stack cos it will make the tone controls work better, cos of the minimal impedance/buffer thing that goes on in CF stage.

thanks, but there's already a CF driving the tonestack - what I have is the basic Marshall cascade circuit (2203 model) with an extra triode gain stage into the front end but I have a spare triode.

I've been wondering if a CF after the 1st gain stage then into the existing 2203 preamp would be of any benefit.

[tubeswell]

triode driven FX send?

single triode tremolo?

[HTH]

triode driven FX send?

single triode tremolo?

nice idea, but I've got no need for a FX loop or tremolo - some kind of refinement/enhancement to the overdriven tone is more up my street.