The Jumpy Mod

A dramatic amp mod as well as the simplest in the Epiphone Valve Junior Head Tube Guitar Amplifier is known as the “JP1 Mod”. The name derived from the jumper labeled JP1 on the board.
It basically morphs the tone of the guitar amp from one with no definition, dark, to an instant edgy and more present tone. To my ears things came to life using the Fender Telecaster compared to the raw un-modded amp I had.

And all this without even replacing the tubes that the amp is shipped with (Sovteks). I suggest replacing the tubes, to a JJ (former Tesla) set. From there things get serious. But at least now for the sake of seeing how much a simple mod like the JP1 can boost your Epiphone Valve Junior tone character.


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Snip It!

That’s all it comes down to – snipping a jumper. Technically eliminating the C3 (22uF) electrolytic cathode capacitor from the circuit on the second half of the pre-amp tube (12AX7). Simple as that! The amp will start singing – but not in falsetto.
All the tool you need is a simple wire cutter (preferably a flat one). No soldering iron, no soldering skillz, NOTHING! You can do it! If you can clip your nails, you can snip the JP1 labelled jumper on your Epiphone Valve Junior.

Follow the steps in the video and report back with comments on your impressions. Good luck!

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