Amplified Switch Noise.

[simon111]

After successfully finishing my first RM, I thought I would be clever and put two in one box and make the second true bypass.(DPDT). The idea was to use it as a secondary booster. So the first one goes into the second one. Then i can switch that one on and off when needed. Without the pull down resistors I was getting terrible popping sounds. With them in the popping has stopped. Only problem is that the switchs actual mechanical sound is being heard. It seems to be being amplified. When I tap the enclosure I also hear that sound being amplified. (like a pickup being tapped).

A friend came over to try out his RM type pedal with a bypass switch on it. Now when I connect my original RM up to his RM, (via a short patch lead) the switch on his RM doesn't become microphonic sounding. (so it can be done I guess?)

So it seems that two boosters in one box is causing this problem. Can anyone shed any light on this? And ways to reduce this.

Cheers.

Simon111

[Meanderthal]

 Check this out:

http://www.diystompboxes.com/smfforum/index.php?topic=47324.0

[simon111]

I have soldered the jacks (crimped bits) and still the same. Slightly microphonic when the 1st boost on (on all the time) and very microphonic when the second boost engaged.

But..................

This is very weird!

If I stick a third booster in front, (standard RM). then it's not micrphonic (perfect no amplified tapping/switch noise)- even though there's more gain. But if I put it after then it is still microphonic.

I have a few of the other pedals that I have to put in front of the booster. But these have no effect and it is still micrphonic (buffer and splitter)


Why would  putting an external booster in front of the twin booster cause the microphonics too stop?

And how can I solve it!!!? (the enigma!)

Hope you guys can help cause I have no clue at all.

Simon.

[simon111]

Quick update. And not sure if this info is vital. But....

When the guitars volume is fully down the enclosure behaves as it should (no amplified sounds by tapping or depressing the footswitch), but when the guitar is full on or even just slightly the microphonics appear.

Again though when using a standard RM before this pedal. The boost does then stop this strange effect.

My thinking is that it's a loading problem? Impedance?