Fender Twin Reverb vibrato switch pop
Moderators: pompeiisneaks, Colossal
Fender Twin Reverb vibrato switch pop
I have a 1973 Fender Twin Reverb amp. When activating "vibrato" with the two switch pedal, there is an electronic pop sound. Solution(s)?
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Stevem
- Posts: 5144
- Joined: Fri Jan 24, 2014 3:01 pm
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Re: Fender Twin Reverb vibrato switch pop
Here’s what to try first if you do not have a new know 100% good 12AX7 / ECC83 preamp tube to work with.
As you view the amp from the rear, right to left there are 6 preamp tubes.
If your normal channel plays fine do this swap.
Take the first 12AX7 / ECC83 on the right ( normal channel preamp section tube) and put it in the socket where the 5th tube from the right is.
This 5th tube provides the Tremolo function.
You do not have to put the 5th tube back in where tube 1 was to make this test, but do put the amp in standby when you make the swap.
When you remove the tubes do so carefully so you can note which way the locational gap is in the tube pins.
If you do not have much experience with removing and installing preamp tubes then it will help to remove the top panel and flip the amp upside down so you can view the inside of the tube sockets .
Be careful because that 4th preamp tube next to that small silver transformer gets very hot as do the 4 large output tubes.
Report back on what takes place .
As you view the amp from the rear, right to left there are 6 preamp tubes.
If your normal channel plays fine do this swap.
Take the first 12AX7 / ECC83 on the right ( normal channel preamp section tube) and put it in the socket where the 5th tube from the right is.
This 5th tube provides the Tremolo function.
You do not have to put the 5th tube back in where tube 1 was to make this test, but do put the amp in standby when you make the swap.
When you remove the tubes do so carefully so you can note which way the locational gap is in the tube pins.
If you do not have much experience with removing and installing preamp tubes then it will help to remove the top panel and flip the amp upside down so you can view the inside of the tube sockets .
Be careful because that 4th preamp tube next to that small silver transformer gets very hot as do the 4 large output tubes.
Report back on what takes place .
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Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
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martin manning
- Posts: 14308
- Joined: Sun Jul 06, 2008 12:43 am
- Location: 39°06' N 84°30' W
Re: Fender Twin Reverb vibrato switch pop
I placed a 180k resistor across the Trem switch inside the foot pedal. Also, ensure that the pedal housing is connected to ground.