Re: Revv G4 Pedal

Posted by HamishR on
URL: http://guitar-fx-layouts.238.s1.nabble.com/Revv-G4-Pedal-Verified-tp45830p46044.html

Same as the "unnecessary" series polarity protection diode.  Yup, it IS unnecessary if you have a good power supply.  But as I found out when showing a friend one of my pedals if you leave that diode out and try to use the pedal with a cheap'n'nasty power supply you can get howling noises.  Put a diode in line between the power and the board and all quiet.  That diode can act as a rectifier as much as a polarity protector.

The 100nF cap on the power filtering reminds me of old tube amps where they would put a 100nF cap in parallel with the 100µF filter caps - Matchless still do this.  Probably a reflection on how dirty power used to be?