JMP100 mod to use other preamps (Amptweaker Tight Metal Pro)

[enuenu]

I asked my amp tech about modding my JMP100 MkII MV so I can run an Amptweaker Tight Metal Pro straight into the power section, bypassing the JMP's preamp. I have heard this is how the pedal works best.

The tech responded enthusiastically saying he has done this mod many times. He said it is complex requiring another tube to be installed, something to do with signal level & impedance matching. He said I would also end up with some clean boost within the amp if I wanted to use it standalone and a serial effects loop. When comparing a Strymon Blue Sky through an amp with an effects loop (Krank K+) as against through the JMP out front, the difference was marked. The JMP is an awesome amp but this effect sounded WAY better in the loop of the K+. So getting a serial effects loop sounds good to me.

What type of pedals can/prefer to be used as a preamp like the Amptweaker? Is it worth getting this mod done?

 

[op1e]

Any amp with a loop is a better amp. That's a great old Marshall and your opportunities for making different tones and mixing different preamps with it abound. Go for it.

 

[Sephael]

You can get any preamp pedal to use, such as the Bogners. Also I find a lot of fuzz pedals can sound really good straight into a power amp. And if you find any distortion pedal you really like you can run it and an EQ into the power amp, not all of them sound as good without a preamp, but some will surprise you.