I have been gone for a while but do have a question on a SF none trem Champ build

[catnine]

Is there anyway to get my SF champ build to sound like my 6G2/5E3 build meaning the 6G2 front end coupled to a 5E3 power section , no NFB and a 12AY7 preamp tube and adjustable fixed bias . Thing is the SF champ has the BF tone stack and it's fine and I did add a NFB control pot but rarely use it. It just seems the BF tone stack sucks out the open tone in a SF champ but I don;t want grind like lifting the tone stack I am not into that. Seems like if I remove the SF BF tone stack and use the one like the 5F2-A or 6G2 has I will then have basically a 5F2-A is that correct?

[tubeswell]

Yeah the BF/SF tone stack is a lot lossier than the 5F2A tone stack, and that was the goal - to produce a cleanish amp.

One way of decreasing the AC load on V1 in the BF amp would be to increase the resistances. Depending on how much you increase them, it might get you a bit more signal preservation, but you'd need to correspondingly decrease the cap values to preserve the same freq rolloff characteristics. E.g.; you could try (say) doubling all the resistance values and halving all the cap values, or tripling or quadrupling the resistance values (and correspondingly reducing the cap values by the inverse proportion). Note that the Bf tone stack is in parallel with the V1 plate resistor and the volume control for the purpose of calculating the AC load, so even quadrupling the resistances in the tone stack might not get you much of a gain.

[catnine]

When I built the amp which is push pull 6V6's and a 12AY7 preamp and a 5Y3 rect basicallu a 6G2 front end and 5E3 power section only adj fixed bias I installed the BF tone stack and found it sucked all the open tone right out of that amp. so I put the 6G2 vol/tone stack back in and left it alone.

I get the impression there is not a lot that can be done on a SE champ by just changing the BF tone stack to a 6G2 with a vol and tone only. After all a SE champ is not like a push /pull amp . I do have a 10" speaker in my SF champ build and I usd to plug my old 73 SF champ into a cab with 2 twelve 8 ohms and got a lot of bottom end.

The SF champ build I did sounds fine I suppose I'm looking for something that I cannot get. My 73 SF champ had a weber sig 8 S speaker I put in it and it sounded pretty good compared to the cheap stock speaker . At times I do feel that a 10" alnico in my sf champ build would help a bit. I had a weber sig 10 ceramic in it but it was really icepicky so i put a RI jensen C10R and that helped a lot.

[tubeswell]

I get the impression there is not a lot that can be done on a SE champ by just changing the BF tone stack to a 6G2 with a vol and tone only.

The tilt control tone stack is another useful 1-knob stack with a good hi-to-lo range on the dial. If you have the 'spare' hole for another knob left over from your BF stack conversion, Merlin's 'Bone Ray' stack (which is a variation of the tilt control but with another knob for mid-hump/scoop control) is great for tweed amps (be they SE or PP). I did one in a PP amp I dubbed the '6H3 Deluxe'* (schematic attached). The mid-scoop/hump control adds quite a bit of versatility to the tilt control. In my version i doubled the resistances (compared to Merlin's version) to minimise the lossiness as much as possible.

* Sorta veeeerrry loosely based on the brown deluxe