Serge - CGS - Buchla - DIY

On this page are my DIY blog entries on all Serge, Cat Girl Synth (CGS) & Buchla related subjects.

Buchla
* Power Supplies
* Low Pass Gate 292 & NLC version
* Buchla 230 Envelope follower
* NLC meets Buchla (metal case designs).
* 16U Portable Buchla case (DJ roadcase config)
* Timbre (NLC build)
* DIY Euro to Buchla power conversion 
* DIY - NLC Dual Drums Build Notes 

Serge - CGS & Driscoll
* Power Supplies
* TKB - Touch Keyboard Sequencer - build notes
* SYNTHACON VCF - CGS 35 build notes
* CGS 86 - Build notes for the Serge Touch Keyboard
* Utility LFO - CGS 58 - Build notes
* CGS 81 - Voltage Processor build notes
* CGS 22 - Master pulse divider - Build notes
* Serge Resonant EQ/Filter - Euro format (CGS 202)
* Serge Bi-Directional Quad Switch (CGS 88)

* Roland mixer - PSU replacement using Ken Stone/CGS ideas

Vintage / Paperface 
* The Morley Serge - Phaser & Reverb repairs (CGS/Ken Stone)
* The Morley Davidson Serge - Reverb Tank - Girls of Milton (KS)
* David Morley's Serge - The Sherman Chaos Bank (CGS/Ken S)
* Morley Serge - Chaos Bank pics (CGS)
* Morley Serge - Final restoration pics (Thanks to Ken Stone)

* Two panel vintage paperface - Pre restoration pics.

* Warren Burt's Driscoll/Serge synth
* Warren Burt - Serge panel 2/2
* Warren Burt - Serge Negative Slew - repairs
* Warren Burt - WAD and TKB restoration pics (NLC & CGS)
* Warren Burt - Driscoll pics

Serge TKB build notes - 10 - Wiring the Faceplate to PCB

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

We are almost there.:-)

We need to make the final connections between the Faceplate and the PCB.
This is the guide:

What do these numbers & letters stand for ? (from left to right):
G – VERT CLOCK
7 – ABCD OUT
3 – A OUT
4 – B OUT
5 – C OUT
6 – D OUT
8 – KV
P – KEYBOARD PULSE
V – PRESSURE
K – RESET
L  – RESET
J – RANDOM SELECT
2 – ON/OFF Switch (Tab closest to panel edge)
N – CLOCK
H – HOLD
M – UP/DOWN
--------------------------------------------
The 4 pot boards also need to be wired to the PCB
 9 – A POTS
10 – B POTS
11 – C POTS
12 – D POTS
--------------------------------------------
17 – LED RETURN

This is how you connected in the 1970s.
I've circled in red  connections 11 & 12 to C & D pots

I'm connecting the A,B,C,D pots from here on the modern TKB:

Almost home. 

Just need to connect # 17 ... the LED RETURN

------------------------------------------------------------------------------------------------------

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

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)

W  GND (BLACK)

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 ***

 

SERGE Modular - Deep Acid House

TKB Build Notes - 8 - Wiring the Touch Keyboard Strip

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

I've cut the ribbon strip to about 60com..... could prob make it a bit longer to make attachment to the mother board easier in the future.

The 16 individual wires from the ribbon strip were separated and cut to different lengths.
(sorry for the out of focus pic).

To quote the 1970 instructions:
"Cut the ribbon cable so that each wire is exactly 1" shorter than the adjacent wire, as shown in the diagram above. This can be done by peeling the blue wire back to 6" from the plug, then peeling the green wire to 7" from the plug, then the yellow wire to 8" and so on. The longest wire will be the brown wire. The length of the brown wire should be about 22". Usually the ribbon cables packed with the TKB kits ore much longer. Strip away about l/8 of insulation and tin the leads for ease of soldering in the following steps."

On the other end I used a female header.

....

It attaches to the mother board thus:

 Below is a pic of the header 70's style:

To quote the 1970's building the TKB kit instruction manual:

"The wiring of the TKB is made easier with the use of 16-pin 'header' plugs that fit into IC sockets on the KBD PC board. The main wiring consists of connecting the various ground busses and signal busses to form a matrix with the 64 potentiometers".

This is a pic of the vintage TKB. - also using the 16 wire ribbon. Construction methods between the old and new are very similar. Nice one Zthee.

Next I installed the wires connecting the touch board with the 16 red pulse out sockets
In the clone they run under the pot boards.

 Here's how they did it back in the 1970's:

Finally soldering these wires to the touch board.
First, the connections to the pulse outs.

I've propped this up with some books.

The 1970 instructions read as follows:
"Position the TOUCH assembly on the panel face where it will later be installed, but do not peel away the backing from the double stick tape. Using masking tape, tape the TOUCH assembly so that it is in an open position as shown in the diagram. Now the wires from the red Pulse Output Jacks can be installed, feeding under the potentiometer wiring matrix, through the cut-outs on the panel, to the LED pads on the underside of the TOUCH Panel. These sixteen pads are in the center of the underneath of the TOUCH Panel. The end pads are split into two sections. The wire to pad 17 will be soldered onto one section as seen from the diagram."

Nice.

Next : Installing the S2 & S3 Ribbon Cables
-------------------------------------------------------------------------------------------------------------

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

TKB Build - 7 Assembly of the front panel

TKB Build - 7 - Assembly of the front panel
Ah, finally the fun part.
Installing jacks, switches, etc.

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

We need:

• 7 x Blue banana jacks
• 24 x Red banana jacks
• 1x Shoulder washer
• 1 x  SPDT toggle

A comparison between the cloned TKB and a vintage one:

Of course, if you want to, you can install jacks with whatever colour you like.
However, if you wish to remain true to the history and legacy of Serge, 24 red & 7 blue are the traditional.
colours

The Vintage TKB is on the top.

The Vintage SPDT switch

Next step: the ribbon cable that attaches to the touch keyboard.
------------------------------------------------------------------ 
***Click here for the Index of the TKB Build ***

TKB Build - 6 - The Touch Keys

The touch keyboard of the TKB is really really special. When I first saw one I was mesmerized. It reminded me of the stylophone that I owned as a child. The Serge TKB however, doesn't need a stylus.

If I understand this correctly the TKB uses the capacitance principle (not FSR - force sensing resistors).
where detection of the plate capacitance is important. Touch keyboards can be found in many instruments (both old & new). The stylophone, the EMS AKS, The PAiA drum & Buchla keyboards from the 60's to the present day are but a few examples.

Useful Links:
1. Muffwiggler Thread
2. That famous Synapse Article by Arpad Benares (care of Cyndustries)
3. PAiA - Touch switches (like those used on their Programable Drum Set)

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

This part of the build involves installing the LEDs

These are tiny surface mounted components. Becareful when installing as they are easy to loose.

Mount as flat as you can & be careful of the orientation. The cathode is to the right.

Part 7. Front panel assembly

-----------------------------------------------------------------------------------------------------------

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

TKB Build - 5 - Pot (Potentiometer) Boards

Finally, after a long delay (due to poor health) I'm finally getting my act together.
The TKB is a dream project. It's a magical instrument & learning how they are put together
is a wonderful opportunity.

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

This next stage involves the pot boards. There are 4 of them labeled A,B,C,D.

 Each has 16 steps.

First lets look at a vintage TKB.

Notice that the resistor connects to the middle lug of the pot.

 A closer view of some of these sixty four 1M resistors.

 I can imagine that soldering all these wires back in the 70's was a tedious task.
Thankfully, Zthee has simplified the process with his 4 pot-boards.

A closeup of the virgin Potentiometer Boards.

Before soldering the pots, instal the 8 right angled IDC connectors & the 64 1M resistors.

Next install the pots. There are 5 holes and each pot has 3 lugs.
I made a mistake in the beginning and installed some in the 3 holes on the right.

 This is WRONG!!!
The middle pin should go in the middle hole, with 2 holes on each side.

This is the right way.

Part 6. The Touch Keyboard (Installing the LEDs)

-----------------------------------------------------------------------------------------------------------

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