Since a couple of months, we've been working on modding some cool little Fender amps, Pro Jr and Blues Jr to be more specific. The journey started in spring '22 when I had the chance to buy a couple of affordable used Pro Jr and started thinking about what was missing to make them great gig-ready and solid amps.
Sadly, those Fender amps are known for their troubles (resistors and caps going bad, hot bias, etc.) and that was the beginning of the quest for me...
Those little 10" combo seems like a great pedal platform to start from. So I bought a couple of transformers from Hammond, "better" speaker to replace the inert Fender one, bigger caps, multi-watt grid resistor, Standby toggle switch, orange drop cap, pots, input jack, and started to mod the first one.
After a couple of iterations, I think I've found the sweet spot to make them great. A combination of the upgrades listed before, with a couple of twist in the tone circuit. The mods are as follow :
- Capacitor and resistor replacement and upgrade (Heavier capacitor rail)
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Speaker upgrade
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Impedance toggle (8/4 ohms)
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Transformers upgrade (Hammond Power and Output Xfo)
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Additionnal speaker jack (Internal AND external connection)
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Negative feedback toggle (turning the amp into a Vox AC15 open-loop amp alike)
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Bias adjustement
- Tone circuit modification (easier tone control) with Orange Drop cap
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Pot Value, new pots (not on PCB), same for the input jack. Quality input jack.
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3-Position Off-Standby-ON switch
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Prof Pinotte Logo and faceplate
We also put Emilie to work and designed a nice "Hot Rodded by Prof Pinotte" aluminium tag to put on the front of the amp to make them recognizable.
That was part of the initial plan to make them easy to spot on stage and I think we nailed that. Adding a second output jack was perfect to bring the little 15W to a monstrous tone machine. Just bring your favorite cab and you're ready to go with both cabs on!
The negative feedback mod (NFB) also turn the amp more into the old school Vox Open-loop AC15 territory.
The mods are not cheap, the speaker upgrade, the transformer upgrade, the initial amp price (we search for those on the used market) bring the total price between 700-900$CAD. That's the price (here in Canada) for a new unit, but keep in mind that you're getting a truly hot rodded piece of gear with those PP Pro Jr.
The latest addition to the GUP Tech Pro Jr modded series is a custom tolex job, done locally by a friend of ours, with a unique combination of Prof Pinotte Green and a Cream racing stripe, giving the little amp the last bit of look you'd like from something coming from GUP Tech.
Have a look at them on the amp page and let us know what you think! They are all unique for now.
https://guptech.ca/collections/amp
