490 fixed tones from HH+S

[nikogo]

The following scheme is a compromise between desired switching combinations and minimization of control units.


We have two humbuckers and a single, more precisely a piezo bridge pickup. For example L. R. Baggs X-Bridge.
The main difference between this scheme and the scheme:
guitarnuts2.proboards.com/thread/7439/400-fixed-tones-hh
is the pickup selector S5.
Here is shown a mechanical rotary encoder - a tiny 8 position device that provides all possible combinations for 3 pickups in binary sequence. 
Switches S1 and S2 give 4 combinations for the neck HB: parallel, 1 and 2 single coil, series.
Switches S3 and S4 do the same for the bridge HB.
Selector S5 connects:
- 1 - neck HB
- 2 - bridge HB
- 3 - neck + bridge HB
- 4 - X-bridge
- 5 - neck HB + X-bridge
- 6 - bridge HB + X-bridge
- 7 - neck HB + bridge HB + X-bridge
- 8 - none.
The piezo pickup is connected through a buffer on a follower J201 with high input impedance 5 M that allows to pick deep bass with x-bridge.
The input divider is used to adjust the high signal from piezo pickup to the (not enough) high output humbuckers (for example: Dimarzio Steve's special). The capacitor C10 is compensating loss of trebles in divider. 
The rest in the same as in previous scheme.
The PCB layout is here:



The way I placed bufers in my guitar is here: (sorry for poor pictures)




Controls on the last picture are on the top side. From left to right:
- rotary filter selector;
- treble cut filter potentiometer;
- S1,S2, S3, S4;
- pickup selector S5.

Here only parallel combinations are used between pickups.