Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: punkykatt on January 12, 2011, 10:29:19 am
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Hey Guys, is there any tone control advantage to using the 350ka treble pot with the 70% tap and cap to ground in the Fender tone stack(ie 6G_ series amps) apposed to the 250ka treble pot in the other similar Fender tone stacks? Or did Leo get a real good deal on those 70% pots and altered the circuit to accomodate? Just curious. Punky :dontknow:
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All I can tell you is that I used one of those pots in the Normal channel of a Blackface Super Reverb clone. Unfortunately, there were so many other deviations from the stock BF component values in the Vibrato channel that I never had the opportunity for an A/B test.
I'm not qualified to analyze this tone control circuit, but it seemed like it provided more mids than a stock Fender TMB tone stack. A bit less very high end too. The amp's owner absolutely LOVES the Normal channel with his Stratocaster. He's owned that guitar since 1981 and says he never really liked it until he played it through this amp. Please note that he plays mostly classic jazz and likes a clean but warm tone. I did tweak the Brown VibroVerb values a fair amount - 82K slope resistor, 9K mid resistor, and a 0.033uf mid resistor after experimentation.
My guess is that the circuit was designed with the tapped pot, Leo bought a bunch of them but switched back to a (cheaper) 250K audio pot when his supply ran out.
Hats off to Doug by the way! He was nice enough to stock these tapped pots after I asked him about it. :grin:
Bottom line - try it! My experiment with it sure turned out nicely.
Cheers,
Chip
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> advantage to ...? Or did Leo get a real good deal
Both.
That re-connection allows treble-cut, which the conventional Fender stack does not do much.
But I bet the killer-deal was that Mono was going out of style, thousands of mono volume pots with loudness taps were hanging around a warehouse unwanted, and Leo got a price.
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Thanks for the replys. Punky