Vox AC 30 TOP Boost reissue Trem intensity

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Markusv
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Vox AC 30 TOP Boost reissue Trem intensity

Post by Markusv »

Hi Folks

Do any of you know what component sets the tremolo intensity in this circuit?
The pot only varies speed

I have one on the bench with overly intense tremolo and want to reduce it

http://www.voxamps.com/downloads/circuits/ac3093pr.jpg

Thanks!

Markus
.........Now where did I put it?
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alvarezh
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Re: Vox AC 30 TOP Boost reissue Trem intensity

Post by alvarezh »

Maybe this variable resistor?

Al the best.
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Horacio

Play in tune and B#!
Markusv
Posts: 393
Joined: Wed Dec 21, 2005 3:16 pm
Location: Toronto, Canada (yes it's friggin cold!)

Re: Vox AC 30 TOP Boost reissue Trem intensity

Post by Markusv »

Thanks Alvarezh

I forgot to state that the trimpot works to some extent but turning it down (even completely) is still not enough
Additionally- If I turn it down I lose my tremolo (pitch shifting)

Also to clarify:
If say Vibrato - I mean the amplitude shifting effect and if I say Tremolo I mean the pitch shift

So I want to keep the pitch shift as it is
I want to remove some of the Amplitude changing ability

Markus
.........Now where did I put it?
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martin manning
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Re: Vox AC 30 TOP Boost reissue Trem intensity

Post by martin manning »

Looks to me like reducing the LFO signal with the trimmer won't reduce the depth of the vibrato without reducing the tremolo effect just as you have observed. The series of high-pass filters just before the volume control is taking out low frequency (i.e. vibrato) content, with a corner point at about 34 Hz. The only way I can think of to reduce the vibrato depth further is to insert another 4n7/1 Meg high-pass filter, which would cut another 12 dB at 9Hz. A little larger resistor, say 1M2 to 1M5 would take a little less off, and also keep from reducing desirable audio frequency content any more.
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