Double power amp sections - Champ Mod

[pistolplc]

Amateur here. 

Looking to build a tweed champ kit.  Earlier suggestions in this forum said to build (or buy) an attenuator to get smaller volumes. 

Another thought I had was that it would be cool to have a second switchable power amp section - like a 1 watt power section.  I know it wouldn't give me the same tone, but it would be a quieter output, and would just be kind of a cool mod. 

Has anyone tried something like this?  If so, do you have any schematics or component recommendations?  Would I be able to fit this in a tweed chassis?  Thanks!

[kagliostro]

Assuming you have a 6V6 power tube and you want to add a small power section I think to a tube like a 12AU7  - 6SN7 - ECC99 (all this with paralleled triodes)

but this tubes requires a different primary impedance on the OT so I think this implies the use of a second OT suited for one of this tubes

is this convenient to be done .... I don't know 

EDIT: I remembered the Traynor Dark Horse DH15H that uses two different tubes (12au7 & 6V6) to have two different output power levels and it uses only one OT, so I think that what you want is feasible, but you can't copy the Darkhorse schematic as is, because it is a PP, not an SE


Save the schematic to see it in full resolution


Franco

[PRR]

Give the 6V6 its own B+ node. Switch maybe 10K 10W in series with the 6V6 stage. Its voltage and power will drop into the 1W zone.

Yes, this is using a Labrador to do a Corgi's work. Yes, not getting full "value for your 6V6 dollar". But a darn sight easier than un-leashing the Lab, finding the Corgi, getting him leashed-up, stocking up on Corgi treats, etc etc. Building a whole 'nother power amp, even small, is more work, plus more work for switching the several nodes. (And the 1-W tube is likely to want a much lower B+ anyway.) Strangling the 6V6's supply gets you there simpler.

[kagliostro]

That is a nice idea, a sort of VVR set for fix voltage drop value without the regoulator


Franco