Welcome To the Hoffman Amplifiers Forum

July 25, 2026, 10:46:22 am
guest image
Welcome, Guest. Please login or register.
-User Name
-Password



Hoffman Amps Forum image Author Topic: 5E3 Build, Pre-PI Master Volume Question For The EE's  (Read 403 times)

0 Members and 1 Guest are viewing this topic.

Offline Jazzcab

  • Level 1
  • *
  • Posts: 8
  • I love Tube amps
Hoffman Amps Forum image
5E3 Build, Pre-PI Master Volume Question For The EE's
« on: July 18, 2026, 03:26:30 pm »
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.



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?



TIA

« Last Edit: July 18, 2026, 03:30:01 pm by Jazzcab »

Offline sluckey

  • Level 5
  • *******
  • Posts: 5277
    • Sluckey Amps
Hoffman Amps Forum image
Re: 5E3 Build, Pre-PI Master Volume Question For The EE's
« Reply #1 on: July 18, 2026, 04:42:34 pm »
Both caps are necessary. The 470K grid stopper is not needed but you may like it.

Offline Jazzcab

  • Level 1
  • *
  • Posts: 8
  • I love Tube amps
Hoffman Amps Forum image
Re: 5E3 Build, Pre-PI Master Volume Question For The EE's
« Reply #2 on: July 18, 2026, 05:33:47 pm »
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?

Offline sluckey

  • Level 5
  • *******
  • Posts: 5277
    • Sluckey Amps
Hoffman Amps Forum image
Re: 5E3 Build, Pre-PI Master Volume Question For The EE's
« Reply #3 on: July 18, 2026, 05:43:25 pm »
I don't think so.

 


Choose a link from the
Hoffman Amplifiers parts catalog
Mobile Device
Catalog Link
Yard Sale
Discontinued
Misc. Hardware
What's New Board Building
 Parts
Amp trim
Handles
Lamps
Diodes
Hoffman Turret
 Boards
Channel
Switching
Resistors Fender Eyelet
 Boards
Screws/Nuts
Washers
Jacks/Plugs
Connectors
Misc Eyelet
Boards
Tools
Capacitors Custom Boards
Tubes
Valves
Pots
Knobs
Fuses/Cords Chassis
Tube
Sockets
Switches Wire
Cable


Handy Links
Tube Amp Library
Tube Amp
Schematics library
Design a custom Eyelet or
Turret Board
DIY Layout Creator
File analyzer program
DIY Layout Creator
File library
Transformer Wiring
Diagrams
Hoffmanamps
Facebook page
Hoffman Amplifiers
Discount Program