18 Watt TMB tremolo noise
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18 Watt TMB tremolo noise
Hey all,
I am almost done with an 18 watt TMB with reverb and tremolo, built like JMP guitars version. It sounds fantastic but I have one issue I can't figure out though. I used an rca jack for the tremolo because I had the footswitch on hand already. If the pedal is plugged in everything works perfectly but if it's unplugged, there is a loud ticking and other noise. I noticed that there is a .01 cap in the schematic that I can't find in the layout. I've circled it on the schematic below.
Do I need to add that in somewhere? Is the RCA jack the problem?
Thanks!
I am almost done with an 18 watt TMB with reverb and tremolo, built like JMP guitars version. It sounds fantastic but I have one issue I can't figure out though. I used an rca jack for the tremolo because I had the footswitch on hand already. If the pedal is plugged in everything works perfectly but if it's unplugged, there is a loud ticking and other noise. I noticed that there is a .01 cap in the schematic that I can't find in the layout. I've circled it on the schematic below.
Do I need to add that in somewhere? Is the RCA jack the problem?
Thanks!
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- Bieworm
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Re: 18 Watt TMB tremolo noise
Think it’s a ground loop. Experienced that once too. Use an isolated jack and ground the tremolo on the ground buss near the cathode ground of the tremolo
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Re: 18 Watt TMB tremolo noise
That .01uF cap is optional. You can add it in, switched or otherwise, but all it effects is the tremolo speed.
See Bieworm's note above, you need an isolated jack.
Thanks,
Josh
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Re: 18 Watt TMB tremolo noise
Isolating the jack and moving the ground did the trick, thanks guys!
One more question, the tremolo intensity control works, but even when it is at zero I'm hearing some trem happening. The footswitch shuts it off, but the pot at zero does not. Is this normal for this design?
One more question, the tremolo intensity control works, but even when it is at zero I'm hearing some trem happening. The footswitch shuts it off, but the pot at zero does not. Is this normal for this design?
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Re: 18 Watt TMB tremolo noise
No it won’t completely shut off because a pot always bleeds some signal, even at both extremes.aabbs20 wrote: ↑Tue 02/28/23 11:51 amIsolating the jack and moving the ground did the trick, thanks guys!
One more question, the tremolo intensity control works, but even when it is at zero I'm hearing some trem happening. The footswitch shuts it off, but the pot at zero does not. Is this normal for this design?
I don’t see the problem when it can be done with a simple switch though…
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Re: 18 Watt TMB tremolo noise
If you want to be fancy, you could using a switching pot, or add a separate switch like I use in the PCB versions.
Without grounding out the trem, the trem is always active, just not as noticeable. I don't get any ticking, you might want to try different tubes and see if any are better. Or post your new voltages and maybe we can make some suggestions based on that.
Without grounding out the trem, the trem is always active, just not as noticeable. I don't get any ticking, you might want to try different tubes and see if any are better. Or post your new voltages and maybe we can make some suggestions based on that.
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Re: 18 Watt TMB tremolo noise
A switch might be the way to go.
It sounds great and is not ticking now, it's just on all the time even when the pot is at 0. I've built some tweed amps with tremolo and when the dial is all the way down the trem is virtually off. In this amp it's still pretty noticeable. What's the best way to decrease the overall depth of the trem?
Thanks guys.
It sounds great and is not ticking now, it's just on all the time even when the pot is at 0. I've built some tweed amps with tremolo and when the dial is all the way down the trem is virtually off. In this amp it's still pretty noticeable. What's the best way to decrease the overall depth of the trem?
Thanks guys.
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