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41

Misc Schematics and Layouts / Re: Groove Tubes Soul-O Single Schematic

« Last post by tdlunsfo on June 06, 2026, 06:32:45 pm »

Maybe.. it certainly wouldn't make sense for the screen voltage to be higher than the plate but I do seem to remember some strangeness here. Unfortunately, I dont have it in front of me anymore, but the next time I get in for repair, I'll double check to be sure.

42

Tube Amp Building - Tweaks - Repairs / Re: Tube Preamp SMPS

« Last post by Jonas on June 06, 2026, 11:48:05 am »

Pete, what was your approach to eliminate the switching noise? Do you have any recommendations of things to try?

thanks!!!

43

Other Topics / Re: Meme of the day

« Last post by shooter on June 06, 2026, 11:30:13 am »

....

44

Tube Amp Building - Tweaks - Repairs / Re: Ch. Mixing resistors of 100K, 220K, 270K or 470K?

« Last post by pdf64 on June 06, 2026, 02:23:41 am »

The mixing resistors are in the grid circuit, do as their value increases, the Miller capacitance LPF corner frequency decreases.

Are you maybe thinking about the two 68Ks for the HIGH and LOW input jacks?

As for mixing the two channels together... There are no mixing resistors in a stock 5E3. The two volume pots act as mixers.

     https://el34world.com/charts/Schematics/files/Fender/Fender_deluxe_5e3.pdf

I was thinking about the first section of the first post, the Traynor / Marshall scenario, as I couldn't make sense of it in the 5F2/5E3 context.

I tried to put that forward as a general consideration, so yes it also applies to the input mixers, though the 68k value there is pretty much ubiquitous.

The Miller capacitance will interact with the effective source resistance of the signal at the grid.
With the 5E3 type arrangement, that will vary depending on the settings of the volume controls, I suppose it's part of the control interactivity thing they're known for.

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Tube Amp Building - Tweaks - Repairs / Re: Ch. Mixing resistors of 100K, 220K, 270K or 470K?

« Last post by shooter on June 05, 2026, 07:40:42 pm »

my 8th grade English-comp understanding of the OP;


"Can anyone reveal the ways the various values of mixing resistors behave in the circuit? This early Traynor had 100K ones


"That amp is finished and now I'm doing up my 5f2/5f3 Frankenbeastie with a stacked tone pot. What should I choose for those mixing resistors? Maybe I'll use 220K like on a Fender AB763




maybe OP's schematic might clear up the english??

46

Tube Amp Building - Tweaks - Repairs / Re: Ch. Mixing resistors of 100K, 220K, 270K or 470K?

« Last post by sluckey on June 05, 2026, 05:55:30 pm »

The mixing resistors are in the grid circuit, do as their value increases, the Miller capacitance LPF corner frequency decreases.

Are you maybe thinking about the two 68Ks for the HIGH and LOW input jacks?

As for mixing the two channels together... There are no mixing resistors in a stock 5E3. The two volume pots act as mixers.

     https://el34world.com/charts/Schematics/files/Fender/Fender_deluxe_5e3.pdf

47

Tube Amp Building - Tweaks - Repairs / Re: Ch. Mixing resistors of 100K, 220K, 270K or 470K?

« Last post by pdf64 on June 05, 2026, 05:38:37 pm »

The mixing resistors are in the grid circuit, so as their value increases, the Miller capacitance LPF corner frequency decreases.

48

Tube Amp Building - Tweaks - Repairs / Re: silvertone 1484

« Last post by bmccowan on June 05, 2026, 11:04:17 am »

Alternatively you could use a parallel power supply scheme similar to what most Matchless amps use. That would allow the selection of individual dropping resistors without a significant effect on voltage delivered to the preamp stages. Sorry if that just complicates the discussion.

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Tube Amp Building - Tweaks - Repairs / Re: Ch. Mixing resistors of 100K, 220K, 270K or 470K?

« Last post by sluckey on June 05, 2026, 09:45:59 am »

There are no mixing resistors in a stock 5E3. The two volume pots act as mixers.

50

Other Topics / Re: Meme of the day

« Last post by shooter on June 05, 2026, 09:16:56 am »

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