My design - audio part

I started my first prototype PCB. The schematic & layout is drawn in Orcad. I based the design on the JCM2000 triple lead because of the high gain and also on the fender hotrod deville amp. In total three 12AX7 tubes. Some of the features I included:

1) Three I2C controlled tone control ICs, to have maximum flexibility.
2) First output after 1 tube stage for very clean output, could also be nice for acoustic guitars.
3) Return before the last tube stage
4) Tube output buffer with 12AX7
5) One high level output and one low level output
6) double layer PCB
7) leaded components top side, smd bottom side

This is only the audio part, the microcontroller with midi input and front panel stuff has to wait because first the audio part has to be perfect.


Yesterday I received the empty PCBs, I put on the tube and the jack sockets. The next month I have to do some building / debugging and tone seeking...

In the pipe line:

(1) Control: For the microcontroller and the front panel I have some idea's. Using the LPC2468 arm processor (olimex development board Olimex LPC-E2468) running Linux (yes I know it is overkill) in combination with a display on the front panel (Matrix Orbital GLK19264-WB). I hope that the display does not cause any noise. Probably I need some help with the i2c drivers.

(2) Power supply: The SMPS must have a +400V, +19V, -19V, +5V output. Most probably it will be a flyback with PFC stage.