help grafting a piece of one amp onto another.

[Old Tele man]

Franken-amping?

[Chuck H]

Frampenstein's monster.

[Chuck H]

Well, sometimes. But most often, the people cleared would be me.

Got the schematic mostly typed in. It might be missing a couple of grid stops. And I haven't yet figured out how to put a signal label e.g. "A" that refers to some other point labelled "A". Seeing as its Thanksgiving, and about 14 degrees outside, Im not betting that I can get the house to get some more smoke test playing in today.

Would like to fiddle with the plate voltage on the OD tube.

I see a couple of things. There may be more. I didn't look that close yet.

You're going to want a ground reference on the 1 and 6 lug connection of the OD switch or it'll probably make an audible pop. 1M to ground should be fine.

You've effectively removed the 50k trem pot that would ordinarily load the reverb/trem channel. This is going to change the impedance and gain of that channel, and therefor the tone will be altered from the stock type circuit. If it matters.

[mikepukmel]

I see a couple of things. There may be more. I didn't look that close yet.

You're going to want a ground reference on the 1 and 6 lug connection of the OD switch or it'll probably make an audible pop. 1M to ground should be fine.

You've effectively removed the 50k trem pot that would ordinarily load the reverb/trem channel. This is going to change the impedance and gain of that channel, and therefor the tone will be altered from the stock type circuit. If it matters.

Way cool, thanks Chuck!

Will add the pop killer resistors.

Re 50k pot and loading, should I put a 50k resistor to ground there and see how it sounds? Any idea what the effect on tone would be? As for tone, Ive had a few of the old Fenders way back in the day, and heard many over the years, but I do know this doesn't sound like any old Fender I've ever heard then or since. Wondered if it was mainly speaker and tubes, but things like this!

[mikepukmel]

Franken-amping?

Some people JUST can't leave well enough alone.

[nosaj]

Some people JUST can't leave well enough alone.

Call it the Al Franken model amp.

nosaj

[mikepukmel]

[Chuck H]

IMHO the 50k loading of the reverb/trem channel on old Fenders was always a detriment. In fact one the popular "SRV" mods has been to disable the trem on those old amps to lift that pot load from the channel. I'd say do it the way you're arranged now and then, if the gain on the "clean" channel is too much you can deal with it after in a better way than a blunt 50k load.

[mikepukmel]

IMHO the 50k loading of the reverb/trem channel on old Fenders was always a detriment. In fact one the popular "SRV" mods has been to disable the trem on those old amps to lift that pot load from the channel. I'd say do it the way you're arranged now and then, if the gain on the "clean" channel is too much you can deal with it after in a better way than a blunt 50k load.

Thanks Chuck, great info. So, the "thousand monkeys typing 10,000 years" thing comes up: Got here by accident. Since I don't use both channels at once, I don't have a side by side, but oh yeah, the OD channel really pushes a lot harder than the Trem-without-trem channel now. I was actually able to get feedback, which this amp could not do before. Im not sure if that made it happy or angry.

[mikepukmel]

Well, I got the grafting done, as per the schematic above, except for the switch (since I don't have a switch). After tinkering some more, the overdrive part sounds even more bright than the typical deluxe. Just way too bright. Too much high freq, not enough mids and lows. I checked the wiring and parts, they all look correct. I have the 100k trim pot set fairly low, so even with all 3 pots set fairly high, it doesn't go into hard clipping, like 'fuzz'. Reading up on what to do to get rid of some of the screech (not feedback or oscillation afaik, just really bright.

its a LOT louder than the reverb channel now. Not concerned about it, just that it is louder. Wondering if its running into a limitation like the PT doesn't have enough oompf to push the OD stage into overdrive and keep everything nice-a-nice.

Oooh. I think at least once or twice you guys had recommended this one:

https://www.ampbooks.com/mobile/ampl...or/calculator/

So, the 4.7uf bypass caps are the culprit. I have a bunch of extra 25uf 25v stock 'fender-ish' caps. Maybe will try doubling up the 4.7's first, since I have extra as well will put C up to 9.4 uf plus or minus. According to the graph thing above, taht would boost the low E string the same as the 10k band.

That covers boosting low and mid. But, if needed how do I trim the highs? is that the job of varying the coupling caP?

More ciphering . ...

http://www.aikenamps.com/index.php/d...ode-amplifiers

[eschertron]

I just revisited this discussion, yes I know, 1 1/2years later.

Mike, how does the amp feel after this time? Are you still wanting more gain (distortion) out of the extra stage? Have you tweaked the circuit any since your last posted schem?

Inquiring (and house-bound) minds want to know.