Welcome To the Hoffman Amplifiers Forum

September 07, 2025, 12:20:51 pm
guest image
Welcome, Guest. Please login or register.
-User Name
-Password



Hoffman Amps Forum image Author Topic: PPIMV with using 2 different pots of the same value  (Read 3266 times)

0 Members and 1 Guest are viewing this topic.

Offline Ed_Chambley

  • Level 4
  • *****
  • Posts: 3785
  • Nothing is too old.
Hoffman Amps Forum image
PPIMV with using 2 different pots of the same value
« on: November 15, 2011, 08:39:43 am »
Anyone ever done a Master Volume without using a dual pot?  I am asking for 2 reasons, 1 is I don't have a Dual pot on hand and the other is what type of effect you may be able to get from having them separated.  I don't know if it would cause any problems either.

Offline tubenit

  • Global Moderator
  • Level 5
  • ******
  • Posts: 10274
  • Life is a daring adventure or nothing at all!
Hoffman Amps Forum image
Re: PPIMV with using 2 different pots of the same value
« Reply #1 on: November 15, 2011, 09:01:01 am »
See if you can find a schematic of Kevin O'Connor's TUT series "Soma18".  It has a feature that would somewhat answer your question.

Short answer is yes I think that can be done and create a psuedo "SE" however my understanding is that it is not that great of a tone.

IF you always turned both pots exactly the same there would be no issue.

With respect, Tubenit

Offline kagliostro

  • Level 5
  • *******
  • Posts: 7739
The world is a nice place if there is health and there are friends

Offline phsyconoodler

  • SMG
  • Level 4
  • *****
  • Posts: 4679
  • honey badger don't give a ****
Hoffman Amps Forum image
Re: PPIMV with using 2 different pots of the same value
« Reply #3 on: November 15, 2011, 02:16:43 pm »
Just use a single 1 meg audio pot as per the Trainwreck pages.It works fine,maybe not quite as good as the others but pretty damn good IMHO.
Honey badger don't give a ****

Offline Ed_Chambley

  • Level 4
  • *****
  • Posts: 3785
  • Nothing is too old.
Hoffman Amps Forum image
Re: PPIMV with using 2 different pots of the same value
« Reply #4 on: November 15, 2011, 02:58:19 pm »
Just use a single 1 meg audio pot as per the Trainwreck pages.It works fine,maybe not quite as good as the others but pretty damn good IMHO.
Are you just tying into the junction of the cap and resistor and not lifting anything?

Offline sluckey

  • Level 5
  • *******
  • Posts: 5075
    • Sluckey Amps
Hoffman Amps Forum image
Re: PPIMV with using 2 different pots of the same value
« Reply #5 on: November 15, 2011, 03:16:43 pm »
Yes. I have that simple crossline MV on my Matchless Lightning clone. I hate it! But I'm a bedroom picker. Might be more useful in a club scene.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline Ed_Chambley

  • Level 4
  • *****
  • Posts: 3785
  • Nothing is too old.
Hoffman Amps Forum image
Re: PPIMV with using 2 different pots of the same value
« Reply #6 on: November 15, 2011, 03:40:15 pm »
Yes. I have that simple crossline MV on my Matchless Lightning clone. I hate it! But I'm a bedroom picker. Might be more useful in a club scene.

This amp I am looking at adding a master is my baby.  It is sort of a 5f4, fixed.  Tried a VVR in it and pulled it.  I would like to tame it a little for round the house, but it is my favorite amp so I don't want to mess it up.  Right now I can use the tone controls to get a nice sound, but it is still kinda of loud for the house.  That is why I was interested in the SE arrangement, but if the tone is not that great, I might as well leave well enough alone.

Offline chocopower

  • Level 3
  • ***
  • Posts: 581
Hoffman Amps Forum image
Re: PPIMV with using 2 different pots of the same value
« Reply #7 on: November 15, 2011, 05:23:42 pm »
Done and tested im my cathode biased amp.
Instead a pot, i put a switch, so i can go from top to down of the "pot" in a flip...
IMHO, sound way better than others attenuation methods i had tryed. (crossline MV, cathode caps switch, external attenuator)

Just waiting next time i open my Proreverb clon (fixed bias, of course) to test it.
more information.
http://www.el34world.com/Forum/index.php?topic=12251.0

so..

for cathode biased amps: TESTED. (ignore the grounded 6V6 cathodes without resistor... mistake)



and for fixed bias amps: NO TESTED.


if you want a pot ( i tried and just used the extreme options..), just change the switch for the pot and quit the 220k resistor in that side of the PI.
« Last Edit: November 15, 2011, 05:32:28 pm by chocopower »
David

 


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