Is there a Quark 125B thermal problem?

[BrianG]

Yep. The existing slab is ~2mm thick with two pieces of thermal pad (~.5mm each) for a total of 3mm. If you remove the pads, you remove ~1mm of thickness and then the caps prevent the FETs from sitting flush on the case. And yes, the thermal pads are what holds the whole circuit to the case.

I suppose you could waterproof it while you're there anyway. You'll have to use some material that won't weaken or get soft when substantial heat is applied, that won't get brittle after time, and can endure the vibrations and jarring. Maybe epoxy may be a better choice?

You can do whatever mod that makes you feel good. :) I just had good luck with what I did, but I'm sure there are other ways to get the same (or better) results.

Good luck!