Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: burt_toast on November 05, 2023, 08:51:06 am
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hi all,
I'm thinking of starting a new build, this time maybe riffing on a 6g2 Princeton.
But instead of a tweed tone pot, or blackface tone stack between V1a/b, I'd like to only have a bass cut pot in the first stage, with a Vox-style "cut" pot further down the line. I don't like the way a treble pot takes the fangs out of the distortion when it's early in a circuit. I'm not a tech like a lot of you guys, but to my ears, I like cutting treble AFTER the preamp dirt.
My question is this:
Have you seen any examples of this "separated treble/bass" thing anywhere?
thanks,
Scott
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I built a 6G2 about a year ago - it sounds great, so I can definitely recommend it. Can't advise you on your idea of separate tone controls, but what I did was add a Framus mid control pot after the standard tone pot to give it some versatility. That basically serves as a mid cut, and I've got it switched so it can be completely out of the circuit.
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Thanks Dogburn, will have a look a the Framus circuit
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There’s 4 iterations of the Brown Bassman, all have the split tone controls you’re asking about, in their bass channel.
Here’s the first -
https://el34world.com/charts/Schematics/files/Fender/Fender_bassman_6g6_schem.pdf
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Thanks pdf64, that's interesting, never noticed that schematic til now. :). My thought here is to let that first stage be kinda snotty and wide open (only tightening low end, as needed), and trimming back highs later--almost post-production like. heh...
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... instead of a tweed tone pot ... I'd like to only have a bass cut pot in the first stage, with a Vox-style "cut" pot further down the line. ...
Check out the Bass control in Matchless amps like the Clubman 35 (https://el34world.com/charts/Schematics/files/Matchless/Matchless_clubman.pdf).
Ignore the resistors, and pretend you have only C1 (0.022µF), C2 (some other value, same or smaller), and VR2 (1MΩ, the Bass pot). You might not even include the resistors if you don't want to.
Caps in series result in a total capacitance that is smaller than the lower-value capacitor. The caps shown in the schematic would be 0.002µF total if VR2 is dialed so the wiper (lug 2) is at Lug 1.
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Cool! Thanks HotBluePlates, will dig into that one
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...yeah, I like the Matchless bass circuit - I think that's the one to try - thanks!
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The 6G6B bass channel is another one to try.