Re: Nocturne Junior Backyard Preamp

Posted by induction on
URL: http://guitar-fx-layouts.238.s1.nabble.com/Nocturne-Junior-Barnyard-Preamp-tp50362p50372.html

baouftou wrote

There is a germanium transistor on the board on the top left that is covered with plastic spread, right?

Looks like an eloctrolytic capacitor to me. I only see one transistor on the board. But I could be wrong.

But I don't know anything about the pedal other than what I can see in the picture and what's on the website:

This FET based preamp uses a hand selected/spec'd NOS Motorola transistor and a mix of imported Soviet germanium & Fairchild silicon diodes at its core with other sexy components like NOS Mial Caps, NOS Cornell Dublier & Mullard and/or Wima film caps...

The topography of a single jfet preamp has only a few variations and clipping options, and there's not a lot of components on that board, so you can probably start with something like this for the circuit:



But it's the component values that matter, and you'll have to figure those out yourself. The Body and Depth switches could be input and output caps, and the channel switching could be an alternative source resistor or capacitor to modify the gain and/or EQ. My best guess for the diodes is asymmetric anti-parallel hard clippers to ground after the output cap, possibly with a softening resistor between the cap and the diodes. The breadboard is your friend here.

This is all just guesswork based on the website and photo. Let me know if any of it is unclear.