Is there a straightforward solution?

[DustinBryant]

I own a Marshall 18 clone, and it's experiencing a "tremolo thumping" issue, similar to the trem ticking in Fender amps. The problem becomes noticeable when reaching a speed and intensity setting of "4" or higher, with the thump increasing along with the speed, much like the trem ticking in Fender amps. The tremolo circuit in this amp mirrors that of the Marshall 18 circuit. Is there a straightforward solution to eliminate this noise?

[Daviedawg]

Welcome.
This is an issue with the 18 watt trem design which has been raised on this forum in the past, though not for quite a while that I can recall.

Try swapping your preamp valves around. Or better, if you have spare 12ax7 of a different make, substitute that in the trem channel. The trem can be sensitive to voltage and even individual valves.

If that does not help do a search on here to see what comes up.

Dd

[Bieworm]

IME the most probable causes are:
1. Individual tube. Try some other tubes and keep the quietest one.
2. Lead dress in general
3. Ground location of the trem circuit. Ground the trem cicuit at the cathode ground of this circuit.
4. Solder joint quality
5. Location of the FS jack

In some cases the thump doesn’t disappear completely, but to an acceptable level