razbo
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Post by razbo on Apr 8, 2011 19:05:02 GMT -5
Hi, I hope this make sense...
If the value of a tone potentiometer is too high on a guitar (say 1meg on a HB), then the actual useable tone control will all be at one end (like 1 on the dial), correct?
If this is true, then can I apply the same principle to an amplifier that has useable tone near one on the dial. I was hoping a smaller pot would be an easy upgrade if that waas the case.
Or is this not a good idea? I have looked at some amp diagrams and it seems the pretty much the same wiring and values as a guitar.
Any input would be appreciated, thanks!
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Post by jcgss77 on Apr 8, 2011 20:11:27 GMT -5
I would say that possibly you could remove old pot, and install a newer, smaller pot with a resistor in series (to ground, I assume?) which would add up to a resistance a bit lower than what you started with.
To experiment, you could solder in a wire for each lead going to this tone control, and go crazy with different values on a breadboard. Go Nutz! ;D
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Post by sumgai on Apr 8, 2011 23:42:05 GMT -5
raz,
Don't get too jumpy just yet. What you contemplate will work fine on some amps, not on others.
What make and model of amp are dealing with here?
sumgai
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Post by JohnH on Apr 8, 2011 23:56:19 GMT -5
If your amp has one of the usual types of tone stacks, the venerable 'Duncan's Tone Stack Calculator' might be useful to check the likely effects of tweaking values. www.duncanamps.com/tsc/John |
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razbo
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Post by razbo on Apr 9, 2011 5:03:38 GMT -5
To experiment, you could solder in a wire for each lead going to this tone control, and go crazy with different values on a breadboard. Go Nutz! ;D That's a pretty good idea in general. More shopping to do... What make and model of amp are dealing with here? Ha, you got me! How may posts have I read and thought "why didn't that dummy just say what amp/guitar/whatever??" The amp is a Jet City JCA50H (50 watt). guitars.musiciansfriend.com/product/Jet-City-Amplification-JCA50H-50W-Tube-Guitar-Amp-Head?sku=430427I'm not meaning to compare this amp to the greats that have been made, but I've read about certain amps having a tone stack that creates a very high end. Some Marshalls, etc, maybe? Settings on them would be 'well below half'. I believe the term is 'cathode following' or something like that, and the description fits. JC has not been forthcoming with any info aside from advice to go to a tech  , even about plate voltages and stuff. I recently replaced all the tubes with JJ's and biased it (first time bias, yay me). This improved the sound but did not warm it up much. If your amp has one of the usual types of tone stacks, the venerable 'Duncan's Tone Stack Calculator' might be useful to check the likely effects of tweaking values. I don`t think this brand has made the big time yet, so it wasn't in the list. Overall my objective is to warm up the amp, and I thought I could get some better tone tweaking with a more useable range. My regular amp is a DeVille, but it's way too loud for rehearsals, so I'm trying out this JCA, which was purchased for more metalish purposes than I am using it for now. Both amps have potentiometer issues; I can't get the treble down on the JC, can't get the volume down on the DeVille  Thanks! |
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Post by thetragichero on Apr 9, 2011 11:51:18 GMT -5
i bet your tone stack is one of the ones on the list under a different name... there's nothing new under the sun  |
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Post by sumgai on Apr 9, 2011 15:00:58 GMT -5
raz,
Check that TSC list for Soldano...... they're the ones who designed the thing.
So far, I haven't come up with a schematic specific to the Jet City stuff, but if push comes to shove, I've got some Soldano diagrams that should be of some assistance. Let me know.
sumgai
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razbo
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Post by razbo on Apr 9, 2011 20:57:12 GMT -5
Hey, guys, thanks! No Soldano on the list, but it still lets me play with values and get the idea how I can affect the stack at different points.
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razbo
Apprentice Shielder
Posts: 36
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Post by razbo on Apr 26, 2011 14:50:33 GMT -5
An update... Still fearful of messing with the innards until I understand better. I don't want to fry anything important. I put a 10 band eq in the loop which is solving my tone problems while I keep on reading. Thanks for all the input!
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, even about plate voltages and stuff. I recently replaced all the tubes with JJ's and biased it (first time bias, yay me). This improved the sound but did not warm it up much.
