Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Jazzcab on July 18, 2026, 03:26:30 pm
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Hey everyone, I'm finishing up an 5E3 build and needed some help and clarity from the more Electrical Engineering minded folks of the forum.
I've read many have had success taming some of the rudeness of the 5E3 (when pushed hard) by placing a grid stopper resistor before the V2b PI. Then some will add that on a switch to have the best of both worlds. I was originally going to do this mod but then...
I was reading there's a camp that instead of that will pull the 1M resistor before V2b PI and replace with a 1M pot to tame the harshness but also adding a master volume in the process as shown here.
(https://robrobinette.com/images/Guitar/5E3P_Build/5e3_Pre_PI_Master_Volume_Schematic.png)
That sounds like an upgrade to the resistor on a switch but some folks report this pot will have a limited response with most of the effect scrunched up into 1/4 to 1/3 of the range of the pot.
Then there's this one below. People report getting a full range from the pot. My question can I omit one of the .022uf caps or are they both needed, can and the 470k grid stopper resistor go? Seems like the 1M pot would be taming the harshness on its own?
(https://www.thegearpage.net/board/index.php?media/master-volume-implementation.343973/full)
TIA
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Both caps are necessary. The 470K grid stopper is not needed but you may like it.
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Both caps are necessary. The 470K grid stopper is not needed but you may like it.
Thanks for your insight. Wouldn't the 1M master pot be doing the same sort of limiting to the V2b grid at lower settings as the 470K grid stopper would be doing with the 1M master at max volume?
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I don't think so.