Epi Valve Junior / GA5 tone stack - where do I put it

[Ashleyslidewhip]

I've been modding my Harley Benton GA5 (almost a clone of an Epi Valve Junior) and thought I'd add a Marshall tone stack. The GA5 already has a "fixed" Marshall tone stack (fixed rather than variable resistors) after the second pre-amp gain stage, so took this out and replaced it with the same circuit but with variable resistors. Trouble is is gives hardly any tone control. The bass acts more like a volume, the treble is marginal and the mid control non existent

I've seen various mod's, builds and designs on the net doing exactly what I've done, but having done it myself I really can't recommend it (for tone control that is - the other mods have turned it into a beast)

Looking at Fender designs, they put the tone stack after the first pre-amp gain stage, so this seems to be the next place to try - but before I take it all apart again can any of you give me some advice?

[olddawg]

I've been modding my Harley Benton GA5 (almost a clone of an Epi Valve Junior) and thought I'd add a Marshall tone stack. The GA5 already has a "fixed" Marshall tone stack (fixed rather than variable resistors) after the second pre-amp gain stage, so took this out and replaced it with the same circuit but with variable resistors. Trouble is is gives hardly any tone control. The bass acts more like a volume, the treble is marginal and the mid control non existent

I've seen various mod's, builds and designs on the net doing exactly what I've done, but having done it myself I really can't recommend it (for tone control that is - the other mods have turned it into a beast)

Looking at Fender designs, they put the tone stack after the first pre-amp gain stage, so this seems to be the next place to try - but before I take it all apart again can any of you give me some advice?

Frankly, I would use it stock and use an eq pedal or a boost pedal with tone controls like a Bad Monkey. The best thing you can do for these amps is replace the cheap Sino tubes IMHO.

[Ashleyslidewhip]

Replacing the tubes is the next thing on my list - I've already done the cathode bypass resistors and caps. As I've drilled the chassis and mounted bass, treble and mid pots I need to get this working better somehow though

Any advice on the best brand of tubes?

[olddawg]

Replacing the tubes is the next thing on my list - I've already done the cathode bypass resistors and caps. As I've drilled the chassis and mounted bass, treble and mid pots I need to get this working better somehow though

Any advice on the best brand of tubes?

NOS RCA for V1. JJ or NOS something for EL84.
I have a stock late production VJ head that I use constantly. I run it through a closed back 2x10 or 2x4 cab though. The combo speaker is crap. I hear the 12" VJ extension speaker is quite good for $99. To get a thick stage sound at a low volume I frequently run a stereo pedal last in my chain driven by a mono signal. Then I run the L and R outputs: one into the VJ head into a Marshall 4x10 cab and the other into an 18 watt Marshall variant head into an old 2x10 Tremolux cab. Both are dimed and boosted. Big sound at club volume and looks like serious gear on stage.

[olddawg]

I should also say that many people put beefier output transformers in these units. I haven't found it necessary in mine. I do know that most of the game changing mods that are on the VJ sites are incorporated in the late production VJs. I don't know if they changed the OT specs.