Tremolo Noise in Normal Channel

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organicsounds
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Joined: Sun 02/06/22 11:40 am

Tremolo Noise in Normal Channel

Post by organicsounds »

I have completed my Mojotone 18 watt build and have run in to an issue where there is a pulsing buzz in my normal channel which changes with volume. The speed of the pulse can be adjusted by the speed pot in the tremolo channel. There is no noise in the tremolo channel. With the tremolo switch plugged in i get a squeal noise or if I hit the switch i get a machine gun noise, remove the switch from the jack and all returns to normal. All this is happening without guitar plugged in. With guitar plugged in both channels pass signal.
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organicsounds
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Posts: 2
Joined: Sun 02/06/22 11:40 am

Re: Tremolo Noise in Normal Channel

Post by organicsounds »

Ok, I solved the Tremolo buzz in the normal channel by moving the ceramic caps around. Other issue with foot switch still exists...
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Daviedawg
Superior Amp Tech
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Re: Tremolo Noise in Normal Channel

Post by Daviedawg »

Good job getting the first part resolved.

For the squeal etc you need to trace the circuit looking for the cause. What you should do is print off a schematic then follow the circuit from the trem channel inputs to the phase inverter marking each node on the diagram and checking the component values until you find something which is wrong. Use the schematic to do this. You may need to do it a couple of times and also double check against the layout as I believe Mojo circuits can have errors in them.

If afterwards you still have an issue you should then post some internal pics of your amp and a description of what is happening. You will get help I am sure.

Dd
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