noise coming from reverb recovery circuit

[Leevi]

I have met this issue some times before and fixed those by doing different kind of rewirings/changes in the circuit but never noticed this simple rule. I have learned it now and hopefully I will remember it as well.
Thanks
Leevi

[sluckey]

Here's a direct link to Hoffman's amp grounding scheme. It can also be easily accessed through the Tube Amp Library link at the bottom of this page...

     https://el34world.com/charts/grounds.htm

Well worth reading. Maybe even save the link for future reference.

[Leevi]

Thanks for the link sluckey
/Leevi

[Leevi]

Want to share here another case I met recently.The amp was a point-to-point converted DRRI where the reverb was noisy even if the recovery input was grounded.I spent lot of time with it trying to move the grounding of the recovery cathode. By moving the 220K grid leak resistor to the grid and grounding it to the ground bus helped a bit. The biggest impact was when I replaced the foot switch jack to an isolated one and grounded it to the ground bus. The noise decreased more than 50% and it is now on acceptable level.
/Leevi