EMS Synthi A + 2 Expansion Cards

via this auction

EMS Synthi A in excellent condition and handled with care. Full Service in 2019 by EMS Expert Constantin (Portabellabz).
+ SQ1 Sequencer
+ Sister Card
+ The following modifications

mode MK1
1 : osc1 sinus
2 : osc1 ramp
3 : osc2 square
4 : osc2 triangle

Oscillators
1. Shape
2. Range
3. Synchronisation
4. Compensation temperature
résistance tempco Tyco LT300014T261K0J on oscillators 1 & 2. More stable.

Filter
1. 18/24db
2. Slew/unslew
Enveloppe
« attack » « decay »
Inverter pins
S&H / Random
Trapezoid Polarity

+ 2 essential cards:

SQ1 Sequencer

The SQ-1 Card adapts the great small Korg SQ-1 sequencer and adds easy plug and play CV/gate facilities to the Synthi.

SISTER CARD

Thick PCB for best stability and solidity

2 identical LFOs
Bipolar signal
Square output
Triangle output
Variable shape of both waveforms
Hi/lo range switch
Lowest frequency : +/- 25 seconds cycle
Highest frequency : +/- 90Hz
Frequency LED

Sample & hold
Clocked by either LFO (3 position switch 1 - off - 2)
Sample input via the meter column
Slew limiter with rate pot and lin/log response switch
Normal CV output
Slewed CV output
Clock LED

2 identical CV modulation busses
Individual level pot for each output of the LFO's and S&H
Left bus CV routed to input channel 1
Right bus CV routed to input channel 2
Mixed output CV inverter switch
Level LED

2 attenuverter pins
Scale and invert signal

Gate output
Fires the Synthi's envelope generator by either LFO (3 position switch 1 - off - 2)"