TTSH gate Booster _build notes

Friday, 21 August 2020

TTSH gate Booster _build notes

I've been testing lots of different euro modules in the search for compliments to some vintage ARP gear... mostly a 2600 & 2500
Both use the same 1V/oct scale which is a good start.
The voltage levels are different to Euro
Euro uses mostly 5V gates & triggers.
ARP uses 10V

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Modulating CVs ... from envelopes, the keyboard and LFOs on the ARP 2600 for example, are mostly in the 10V range.. but I've generally had no problems using Euro for modulation on ARP gear.

For the record:
ARP 2600 Keyboard: CV output voltage
UPPER VOICE −3V–+10V, 1V/oct.
LOWER VOICE −3V–+7V, 1V/oct.

ARP 2600 keyboard LFO
TRIANGLE ±5 V, 10 Vp-p
SQUARE WAVE +10 V, 10 Vp-p
DELAYED SINE WAVE ±3 V, 6 Vp-p

The ARP 2500 envelope generators outputs envelopes between 0 to 10V.
There is also an invertered output on the 1046 module with a 0 to -10V envelope.

Euro are mainly 0- 5V . (MakeNoise modules are in the 8V range ... these thus are more compatible).
So if you wish for example to fully open the filter of your 2500 you might have to boost the euro voltages.
Some modules that output 0 - 10V are:
2HP ADSR
Intelligel Quadrax
Bubblesound 141 (EG/LFO/VCA)
Erica Synth Black EG
Erica Synths Pico VC EG
4MS PEG
MakeNoise Maths
2HP Random (Rnd)
2HP EG
Tip Top Z4000 (envelope generator)
NLC Modules:
"The Dual LFO/vco, Feague and VC ADSR can all be easily modded to get 10V signals.
A bit tricky to get 10V from the Triad, best chance would be remove the LED and replace it with a link, then remove the 4k7 and leave the it empty" (Andrew F)

CV processor & Offset -generator modules will probably come in useful.
Something like the Sputnik CV processor can amplify 0-5V control voltages up to 0-10V ranges.
Other useful modules:
+ Voltage Processor - CGS 81 - Build notes
+ Voltage Processor - CVP - Build
+ Make Noise Maths
+ Synovatron CV Tools
+ Doepfer A-185-2 Precision CV Adder
+ Doepfer A 183 - offset generator

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So the main compatibility issue between ARP & Euro seem to be Gates & Triggers
I've decided to try the TTSH gate booster. It also produces 10V triggers
BTW The Doepfer dual trigger delay.is super useful to generate triggers from gates

Here are some pics from the build.
It's very easy.

And the rear of the PCB

Metal Film Resistors 1% .25w
2 1K R7, R15
1 15K R11
5 18K R3, R4, R5, R12, R13
3 47K R6, R8, R14
1 82K R2
3 100K R1, R9, R10
1 1M R16

Capacitors
1 330p C1 COG or poly/MKT 5mm lead spacing
COG -- Ceramic ??
2 100n C4, C5 Decoupling, cheap 20% disc caps are fine. 5mm lead spacing
2 10uF/50V C2, C3 Electrolytic 2.5mm lead spacing

Semiconductors
1 TL072 IC1 OP AMP DIP-8
2 2N3904 Q1-2 NPN Transistor TO-92
1 1N4148 D1 Gen Purpose Diode

Miscellaneous
2 FB_226 L1, L2 Ferrite Bead, Axial Leads
3 Header Gate_I, Gate_O, Trig_O MTA02-100 Amp Connector
1 Header Power MTA03-100 Amp Connector
1 Socket IC1 DIP-8 Socket Buy a good milled type, or don't bother.

Optional - LED indication
1 2N3904 Q3 NPN Transistor TO-92
1 LED LED Builder's choice, but try to get a diffused one.

1 1K R17 1K is chosen for standard red LED. If you like laser etching your
retinas with a blue or white LED, you should increase this to 5-10K.