M117R MXR Flanger Problems

[Guitar Toad]

I know someone who has an M117R MXR Flanger Pedal. He has two minor gripes with it.

1) There's a loud "pop" noise that occurs whenever the pedal is turned on or off.

2) The signal level seems to drop a few dB whenever it's turned on. Its not much of a volume cut but it's enough to put a minor dent in the solo volume.

Anyone know how to fixed these two problems?

[christian]

Popping switching might be cos of different DC voltages hanging around on and off, so putting some 1M resistors to ground from input(s) and output(s) and possibly from the switching system. Just your standard way of handling it.

Volume cut could be cured by making the circuit amplify a little more. I found 1 schematic of MXR Flanger, not sure if this is the same your friend has,
clickie, you could change the last opamp mixer before the output and change the 100k resistor to somewhat larger value.

ch.

[Guitar Toad]

Popping switching might be cos of different DC voltages hanging around on and off, so putting some 1M resistors to ground from input(s) and output(s) and possibly from the switching system. Just your standard way of handling it.

Volume cut could be cured by making the circuit amplify a little more. I found 1 schematic of MXR Flanger, not sure if this is the same your friend has,
clickie, you could change the last opamp mixer before the output and change the 100k resistor to somewhat larger value.

ch.

So you could just solder in a 1Mohm resistor just after the cap on the input and run it to ground and run another 1M to ground just before the output jack to solve the popping problem? That sounds easy enough. Sweet.

[christian]

So you could just solder in a 1Mohm resistor just after the cap on the input and run it to ground and run another 1M to ground just before the output jack to solve the popping problem? That sounds easy enough. Sweet.

Well, yeah, except 1M resistors to all points on the on/off switch, so that when you kick the switch, it doesnt charge DC which usually causes the popping.

ch.