Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Toxophilite on May 08, 2017, 03:20:36 am
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The intensity pot (250K) for the 6G11a tremelo circuit in my AA964 vibrolux build wasn't doing it's job
It never turned the vibrato fully off, there was always a hint remaining. and I HAD to use the footswitch
It was a smaller cheaper pot so I went and picked up a bigger better quality 250K linear pot from the electronics store across town.
unfortunately, and this a happened to me before from the same %&$#&^% shop but I had forgotten, they mislabelled some sort of specialized pot wrong as a normal pot. This one only works on one side and has NO continuity at full on!. (it turns off)
I was kind of *&^&* off as the place is across town and I don't want to go there again till I can combine it with another errand.
So
Can I use a 500K linear pot temporarily and what will it do the tremelo intensity?
Would I be better off going lower?( I have some 100k)
I tried a 250K log I had and it seemed to go right into whoop whoop territory at about 3
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You could strap a 500k resistor across to two outer lugs of the 500k pot.
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Try your 100k linear pot and see where that lands. The main thing is to ensure that the LFO output isn't too heavily loaded (to the degree that it sucks the life out of the tremolo wiggle) whilst still leaving you with enough slam to get a good effect.
But even 500kN should also work good enough - remember the intensity control pot is just a humble a voltage divider. The output voltage at the wiper is a function of the resistance between the wiper and the fixed bias potential, divided by the total resistance between the pot input and the fixed bias potential.
An audio taper pot will be all happening in one part of the rotation (like you saw already).