Vibroverb Help Please

[scottyfathead]

When my vibroverb is on at any volume you can faintly hear the warble of the vibrato even that is not switched on.You can turn the intensity and speed up and it gets worse.Just like it was on but very very faint.
I dont use the vibrato at all so I figure I will do the Diaz mod that uses a switch pot to disable the vibrato circuit.This should be the easy fix to my unwanted warble as if its out of the circuit it cant make noise.
I installed the switch as in the diagram below.The original schematic has the yellow on the right lug,the brown on the middle and the third lug bent back and grounded.
But on mine the brown is going to right lug,the yellow to the middle and the third lug has a wire running from it to the middle lug of the trim pot just below the intensity and speed pots?Why would that be?And what is that trim pot for? Could the backwards yellow and brown wire be the problem in the first place?
I installed the switch pot as below but kept the yellow and brown wires reversed as they were on my old pot.And my switch does nothing when turned off.There should be a boost in volume but it stays the same.
I have a Marsh Vibroverb

This is a Super Reverb layout but this section is the same as a vibroverb.







[IMG:320:190]http://i697.photobucket.com/albums/vv333/scottyfathead/Tremolo-disconnect-mod_zps84fa9ed5.png[/img]

[martin manning]

Your amp must not be built according to the Fender schematic. The trimmer is likely just a bias adjust, but if you can hear the trem with it switched off, then I suspect that the oscillator is left on in the arrangement you have. Perhaps the driver stage is disabled in some way, but the fluctuating current draw from the oscillator might still be creating the effect. Trace out the circuit as built, or maybe take some good pictures so we can see what is in it.

I wouldn't expect any effect on volume from just disconnecting the trem signal as shown in your diagram since the trem circuit is still drawing current from the supply. There would be more effect if the oscillator and driver were both disabled, by lifting their cathodes from ground, say.

[Firestorm]

Wait a minute. You have an actual Fender Vibroverb and you want to fuck with it? Put down the soldering iron and step away from the bench! 5 or 6 guys here will just buy it from you. As is.

[martin manning]

Nope, Marsh replica.

[Firestorm]

Double. Marsh, eh? K.

[Milkmansound]

just pull the vibrato tube if you don't use it. Easiest solution I can think of

[scottyfathead]

Can I just pull the vibrato tube without harm to anything else?

[Firestorm]

Can I just pull the vibrato tube without harm to anything else?

Shouldn't matter.

[scottyfathead]

AS it turns out this is a 63 style brownface housed in a blackface cab with a 15.That explains the intensity pot wiring and why the mod didnt work.

[DonMoose]

Can I just pull the vibrato tube without harm to anything else?

Shouldn't matter.

Although it would make me wonder about the filter cap that powers than node in the string.