Wire the pins a, b, c, d, e, f, g, h, i, 6-6a and 10-10a together, as per the diagram above.

Diodes D10-D14 are mounted vertically.

You may use original schematics on this module.


1)  I could never trim the AM well without an additional resistor change. Here’s a solution for this :

- wire a multiturn ~20K trimming resistor across R290A

- find a balance for good-looking (0 to +/-2V) AM with a combination of this trimmer and TR3

- desolder the multiturn trimmer and measure its value

- sum with 22K using a parallel resistors calculator

- replace R290A with the value close to what you get using the calculator

- adjust TR3 if required

2) if you hear a click at the end of TIMBRE range - you will need to wire an additional R* from a junction of TR2 and R213 to -15V rail. On both units i've built 47K worked well, you may want to select the value.

3) The 130K on PCB1 is using alternative SMT 0805 footprint, so the scale may be adjusted easily. Lower the value down for 1.2V and 1V/OCT.