[59] Epiphone Valve Junior mods

Date: December 7th, 2007 | Comments : [6] | Categories: amps, tubes.

Epiphone Valve Jr. head


My new Epiphone Valve Jr. amp head

If you saw my previous post on the Epiphone Valve Junior 5w amp head, you know that I bought it to experiment with some mods and circuit changes. I’ve been looking over the schematic and drawing up some of the mods that I want to try. Here is the initial list of mods I want to make to this little beast.

  • Add a tone control
  • Reduce preamp gain
  • Add a switch for a feedback loop
  • Add a triode/pentode switch
  • Add a conjunctive filter on the OT
  • Add a standby switch

I’m not planning on changing output transformer in the first round of mods, though I have one on hand that would be suitable.

I want to reduce preamp gain because if I need overdrive from the amp, I will use a booster pedal to drive it hard enough to go into saturation

I might also end up changing the values of a few components.

There will be a page on my web site dedicated to the mods and the link will be added to this post when I get it online.

The Epi Jr. is a nice little amp for the dollars and I look forward to turning it into a custom unit drenched in good tone!

 

6 Responses to “Epiphone Valve Junior mods”

[282] JHS Says: 1:34 am, February 2nd, 2008

I recommend tp change the 1N4007 diodes for BY… or other ultra low noise fast revovery Schottky diodes. 1N400.. diodes will be to slow and imply a lot of hiss to the circuit.

JHS


[367] 搅拌机 Says: 2:39 am, March 12th, 2008

Your blog is very beautiful!


[448] Murray Mcleod Says: 7:55 pm, June 16th, 2008

I just got a valve jr and have been looking online for the last few days trying to find the coolest ideas for moding this thing. I finally found it here.

Also, your website rules.

peace.


[620] ted stephens Says: 11:08 pm, February 27th, 2009

what a bout a tung-sol 12ax7 in the preamp section and a bigger transformer and and cut down on the input resistor it shouldn t be this big and for a tube try several and keep them all brands including mesa boogie to rca it doesnt matter if it sounds just leave it alone………


[727] Murray Mcleod Says: 11:01 pm, June 9th, 2009

I completely removed the input resistor.


[2697] Buzzard Says: 8:19 am, March 25th, 2012

Hi, great blog !!
I wonder if a standby switch is useful for my Epiphone Valve Junior.
I don’t really use it that often, but when it’s in use, it turned on and off often, or not at all through the day.
Any ideas ??
Thanks, and best Regards
Peter




 

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