Monday, August 3, 2009

Epiphone Valve Junior - the Gain Matrix Mod



Here's a gain reduction mod I recently completed on an Epiphone Valve Junior. The owner was looking for less volume and less gain. This mod has 3 switches each with three positions:



Epiphone Valve Junior gain reduction with the gain matrix mod



With all the switches set to the left the amp is stock. Flipping a switch to the center position reduces the gain by taking the cathode bypass cap for that stage out of the circuit.

Flipping it all the way to the right switches in a different value cap for the cathode bypass. In the right position the upper two switches act as differently voiced bright/body switches and the bottom one acts as a deep switch.

The amp can now be made quiet enough to be used at home. It can be cleaned up for less gainy sounds and brightened for more clarity. And it can be quickly returned to stock if you miss that muddy sound it had when it was new. The various combinations of three switches give a total of 26 alternate voicings.

I shot pictures of this mod but I haven't written up a whole description. If anyone is interested in seeing the whole process, let me know in the comments section of this post and I'll put the details together.


3 comments:

Anonymous said...

Hi Akavalve,

I'm very interested in seeing the whole gain reduction mod process.
Always reading your blog with great interest.

Thanks!

Robert

johnny said...

i'd also be interested in seeing how you did this.

nice blog!

Anonymous said...

Hi akavalve,

I'd like to see/hear how these mods work too. Please post pics/sound bites and part lists if/when possibel. Thanks for all thus far.