Jim Dunlop M133 MXR Micro Amp Pedal, White

Product Information

R6 is there to help with stability and help preventing oscillation driving capacitive load, same as in Micro Amp.

Front end overdrive channel: works as an amazing gain boost. It does not color the tone at all! This pedal is a perfect choice if you are tired of OD/Distortion pedals that always warp your tone…I like to use DIY Layout Creator to prepare for breadboarding. This step is not strictly necessary, but I prefer to have it done this way. Makes my life easier when it comes to planning, and it looks way more professional for my posts.

As you can see from the photo, the breadboarded effect is nearly 1-to-1 like I planned it. Breadboarded MXR Micro Amp I didn’t have 22M resistor, so I used 10M for R1. This won’t make a difference in sound, it will lower the input impedance just a bit, but nothing significant. Trying it out A secondary function, per the manufacturer, is to slam the front end of a tube amplifier with extra volume to create even more saturated gain sounds than an amp is capable of producing on its own. Again, the M-133 Micro Amp excels at this, too. I've got a Mooer pure boost in the middle of my board which does give a very clean boost but it has a slightly clinical sound when on which the micro amps don't.Finally – R3, I’m not sure, it’s probably there for stability and/or possibly DC error. The pedal has been around since 70’s, I’m not sure how much the design changed, 741-type op-amp has been around since 60’s. Not sure if it is still needed. Reference Voltage