Monday, 15 June 2015

Serge TKB Build notes - 9 - Ribbon cables S2 & S3

***Click here for the Index of the TKB Build ***

Now it's time to attach the second & third ribbon cables.
It total there are 3 ribbon cables that connect the main PCB with the front panel.
They are named S1, S2 & S3.

S1 connects the TOUCH PADS (I have already done this).
S2 connects the PULSE OUTS
S3 connects the  POT BOARDS

On the PCB the connectors are our 16 pin male headers.

 S1 is the header on the right. S2 is the lower header on the left. (S3 above this).
The connections on a vintage TKB are exactly the same.

It's fun to read the original 1970's instructions for building this kit.
They read:
"Connect the three ribbon cables to the appropriate places. Note that one is wired along the row of pulse output jacks, one is wired along the bottom row of potentiometers (with the wires which were not soldered in step 3). The ribbon cable which goes to the TOUCH assembly goes through the cut-outs in the panel to the 16 connectors along the top edge of the TOUCH Panel. There should be the absolute minimum of bare wire extending up from the solder connection to prevent shorts when the TOUCH Panel is installed onto the metal panel. The wires from the ribbon cable that are soldered to the small pads going to the large touch pads should not be inserted into the holes. These leads should be cut very short, and soldered flat onto the pad, using a minimum of solder. It won't affect the operation if wires or solder extend through these holes, but for best appearance this should be."

First up, I'll install the S2 cable.
This connects to the 16 red pulse out sockets.

To clamp the female headers I've used a simple bench clamp.

Now it's time for S3

Below are the ribbon cables on the vintage TKB.
Notice that the S3 cable in the centre connects directly to the pots.

Connect the ground pads with some wire.

It's almost time to start connecting the PCB to all those upper jacks & the PSU

The power connections are circled in red (from top to bottom):

Z  -12V (WHITE) 
X  +12V (RED)

Starting with the ground first.

 On the other side of the pot boards it looks like you only need to connect one of the pot boards to the ground terminal of the PCB. May as well connect the same wire to the toggle switch (middle terminal).

***Click here for the Index of the TKB Build ***


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