Just an edit, your gain pot lugs 1 and 2 should be connected together rather than 2 and 3. The way you have yours wired, turned the pot all the way down (counterclockwise) would be maximum gain and turning it all the way up would be minimum gain.
These videos are great. Are C4 and C6 polarised capacitors simply because those larger values are easier or cheaper to obtain as electrolytic caps than as ceramic capacitors? Would it matter if the polarity was reversed from what’s shown in the schematic? Would bipolar caps work just as well provided you used equivalent values? Thanks!
Larger value caps are usually electrolytic simply because they are cheap for that much capacitance. Bipolar work fine, but if using polarized, don't reverse them, otherwise they can get fried.
R9 is NOT to be omitted!!! It decouples the TL072 from capacative loads like a long guitar cable. The TL series has a tendency to oscillate with capacitive loads. I would suggest a minimum of 100 Ohms. Overall good explanations but you should pay more attention to those RC Filter relations. Making C1 bigger will absolutely do nothing for the bass response if you leave R2 and R1 the way they are. On the other hand you will cut bass if you put 100n in for C5 and leave R10 as 10k.
If I would like to use the MXR Micro Amp pedal as a Booster, it is possible to modify it by adding a volume control like an internal slide or lever switch, or an external small potentiometer? Thanks.
It will work as a boost already. The gain knob is changing the amplification factor of the opamp stage so that you can go from about unity gain to close to 26 dB of gain. At max levels, you might clip the opamp a little, though.
