Turntable preamp?

[hairyspider8]

So I am an absolute beginner, I have a Pyle PP999 phono/turntable preamp. I know nothing about electronics, I was wondering if it would be possible to make any kind of pedal using the circuit.

[Rob Strand]

Sure, those things are just one or two opamps per channel.   The feedback network is going to be fairly useless for guitar.  At the end of the day you will just be building some sort of opamp based pedal.    You could easily re-use the PCB holes for your own resistors and diodes etc.

Heres an example of what's often inside,

[Rob Strand]

You can actually see 470k and 8.2n on the board.   That's like the 910k and 3.3n on the schematic.
Then you can see the 36k and 2.2n.   That's like the 75k and 1n on the schematic.

Basically your circuit has half the resistor values and double the capacitor values.

You can also see 47k resistors which will be the same as the 47k on the schematic.
There are 220pF caps in parallel with the 47k resistors which is 100% normal for
this circuit.  The 47k and 220pF provides the correct loading for the turntable cartridge.

On the output side you will have 1k in series with the output (that's not shown on my
schematic but they should be there).  In series with that is a cap to block and DC.

[Ben N]

Doesn't every Barber overdrive use some variant on that topology?

[merlinb]

You could make it into a simple boost, maybe add clipping diodes like a Distortion+, but beyond that it would make more sense to start from scratch.

[anotherjim]

There's some extra fun maybe by running both channels in series. Out left back into the right. You might fit a volume control in between to adjust the "overdrive".

Isn't the power supply AC? It's bipolar so can't run off a standard 9vDC pedal power.

[merlinb]

.

[anotherjim]

Ah, it's referenced to position the DC half voltage to ground so the PSU must be an isolated type.