Overdrive Reverb/Steel String Singer Hybrid

[ViperDoc]

Do you see anything suspicious around the effects loop jacks, their chassis ground, or how the cable shield grounds are connected? You've lasso'd the shielded wires with what looks like a conductive wire on the preamp ground buss. Is there something there? Ground loop, perhaps?

[beasleybodyshop]

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[beasleybodyshop]

Solved!

Long story short, between performing the PI balance procedure and moving around the PI grid input wire the noise is entirely gone!

Amp sounds absolutely bonkers. I need to get the FET preamp working, so will report back when i get there.

Filters do indeed load the circuit down quite a bit. But amp sounds great with or without them in. Very useable.

Will report back!

[rootz]

Great to hear! I saw the cathode and grid wire of the PI were very close. You might want to rewire the cathode wire to the right side of the PI tube socket. Dumble does that consistently, at least in the pictures his amps I have.

Also, I don’t see grid stoppers on the output tubes? Are they there?

[WhopperPlate]

Curious how the filters work in tandem with the overdrive circuit. Must be bonkers

[beasleybodyshop]

Spent some more time dialing it in, and then stuck it back in the headshell I built for it several years ago. Need to make some final adjustments to the cab but i'm very pleased with how it turned out.

Tone is amazing, will post some decent recorded clips when i get back in a few weeks. Stay tuned!

[beasleybodyshop]

Attached final Layout and Schematic.

Note - Layout does not include Clean Channel Master volume - but that is easy enough to add between the OD drive and Reverb Dwell pots on the back of the amp. Layout is 95 percent correct. Always reference schematic.

[txbluesboy]

Very nice work! This is basically what my El Patron amp is. Are the grid leaks on the output tubes really 47K? I normally see 470K resistors there.

[beasleybodyshop]

Very nice work! This is basically what my El Patron amp is. Are the grid leaks on the output tubes really 47K? I normally see 470K resistors there.

Yes I believe so.

You're out of Grand Prairie right? I'm over in East Dallas/Garland. Not too far away.

[beasleybodyshop]

Also,

You all should try subbing Echoplex EP3 preamp values in lieu of the normal FET. It's so wonderful! Normal impedance too.

[txbluesboy]

I am in Grand Prairie. We should get together sometime.

[WhopperPlate]

Very nice work! This is basically what my El Patron amp is.

Another ODs sss hybrid , very cool , did you keep the filters too ?

[txbluesboy]

I didn't really like the filters on a couple of other amps I built. Too lossy and really I only used 1 setting on the high filter.
I hard wire this low pass filter setting in most of my amps.

[txbluesboy]

https://youtu.be/IZxiDoiJHhY?si=zlENKXn1Yhq1Evmr
Here is a demo a user posted of his El Patron.

[WhopperPlate]

https://youtu.be/IZxiDoiJHhY?si=zlENKXn1Yhq1Evmr
Here is a demo a user posted of his El Patron.

That’s the forward and present sustain I have come to recognize from these hybrids . You know what’s fun ? Listening to your favorite music . Plug a phone into the active effects return and you have a sweet hifi tube sound lol doing it as we speak , ev12l sounds great for playback