Schematic

The schematic was drawn with the software sPlan. By clicking on the image you get an PDF file, which can be zoomed in.

The schematic is based on the schematics of Martin Winterfeld, the FX-loop is taken from Merlin Blencowes book “Designing Tube Preamps for Guitar and Bass”. The FX-loop is not implemented in the Layout.

The schematic assumes a power transformer with a center tap at the 6.3V terminal. If your PT doesn’t have a center tap, then you will have to add a virtual center tap using two 100 ohm resistors.

Schematic (PDF)