TTSH (ARP 2600 clone) build notes - Pre Amp (DIY)

The Microphone PreAmplifer build of the TTSH synthesizer. 

This is part 11 of my TTSH (Two thousand six hundred) build which is an ARP 2600 clone synth.
You can see my full build thread HERE

There are two awesome TTSH threads in Muffs.
2600 clone - Two Thousand Six Hundred (TTSH)
and
Two Thousand Six Hundred (TTSH) Project General Build Thread

The DSL-Man site has a very good TTSH thread

And of course the official build thread is here

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 The front section of the PCB

The back of the PreAmp PCB

There is no submodule for the Pre-amp.

The schematics of the 2600 indicate the use of a Teledyne 1339 Op Amp (A4). This has been replaced with the LM301 Op Amp in the TTSH.

A little on how it works:

The signal enters via R23 (100k resistor) the gain control and is coupled through C24 (a 0.1uf cap for the ARP 2600 & a 100n cap in the TTSH) to the non inverting input of A4 (133901 teledyne).(pin 3)

The range switch (S1) selects the feedback path for A4.
through either
1. R20 (X10),
2. R20(100k) & R 26(10k) (X100),
3. R20(100k) ,R25(1k), & R 28(100k) to ground (X1000)

The amplified signal then passes through pin 6 of A4 and through R27 (1k) to the output.

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TTSH parts list.

Resistors

• 100 x 1 (R28)
• 1k x 2 (R25,27)
• 10k x 2 (R19,26)
• 100k x 2 (R24,20)

Capacitors

• 5p x 1 (C15) --- slightly different from the ARP schemo
• 50p x 2 (C15,C17)
• 100n x 1 (C24) ---slightly different from the ARP schemo
• 10µ x 2 (C13,C14)

Semiconductors and Integrated Circuits

• LM301 x 1 (A4)

Other

• 3,5mm jacks x 2
• 100k audio Potentiometer x 1 (R23)
• DP3T slide switch x 1 (s1)
• 11mm M3 standoffs x 5

RESISTORS & Caps.

Install the jacks & 100k pot.

Install the five M3 standoffs

The BOM specifies 11mm. These are 10mm. They seem Ok.

 First test of the fit of the faceplate.

Looks good. Make sure the sliders, pots, jacks are in the right places.

Sit that slider in the correct position. This is a 10mm gap.

Before soldering check that the slider's pins just poke through.:-)

the switch& op-amp are in.

Wow ... it looks great !!!! Everything fits in place like it should. :-)