Just messing around adding nonsense to one of the guitars I made years ago, and in addition to a nice little stereo preamp I am popping in a mini Korg Kaoss Pad (obviously following a bit of a Muse bandwagon, butI quite like some of the milder tone effects it gives..)

Anyway - the input and output buffer stages are annoying me, as I can't quite figure out values of componenets and I want to do away with this daughter board. These have RCA sockets on the back, so I know the components are just resistors and capacitors (left hand end of the board is output, right hand is input) and the number on the two resistors which have a number is 101.

With just a multimeter I can get all the resistor values, but without something in the time domain, how do I work out the capacitors? Or are there sensible values for this sort of thing which should just work, as it is just an audio effects box?

101 is 100 ohms.

1 - first digit
0 - second digit
1 - number of zeroes after the two digits.

Occasionally you might find 4 digits in which case it's simply 3 digits and then the number of zeroes.

You can get capacitance meters. That's about the only easy way. You'll likely need to disconnect one end to get a real reading though since other parts of the circuit can affect things. Same with resistors really though.

Really need a circuit diagram to figure out what would be "sensible" values.

Cheers Christian,

Might have to go and buy a capacitance meter then. Ah well. The good thing is that this board is currently disconnected.

In terms of circuit diagram, on the input side the resistor and capacitor are in parallel on the signal line, and on the output side I am beginning to think I was mistaken. Appears that we have a resistor and capacitor in parallel, followed by a resistor in parallel with an inductor. Which makes sense if we are trying to rolloff high and low frequencies I guess.

Might make it more fun to figure out values.

Or I could just dig out another hole in the guitar and keep the daughter board :-)

In thinking about this I reckon I can do away with the input stage (or possibly just pop a big capacitor in there for DC separation) as the preamp I built should be suitable here.

Which means I just need something on the output from the Kaoss pad - as it is just feeding in via a normal guitar input to either an amp or a stereo DI I was thinking I don't really need to worry about rolloff, as both of these options have input buffers, so I really just need DC separation again.

Does anyone know enough about this to suggest capacitance/resistance values which would be suitable (I'm thinking 10uF and a 100k potentiometer for the volume control - seem reasonable?)