New Portabellabz expansion card for the Synthi A and
AKS, mostly intended for the experimental Synthi playing
but not only, it's able to create crazy droid sounds as
well as subtle modulations.
The card simply plugs directly into the 8 pins Jones
"keyboard" socket and is powered by the Synthi, no
cables no connector, it's plug and play, easy and hassle
For use with a VCS3, the Jones plug can be mounted onto
the top side of the PCB but an adapted umbilical cable
with swapped connections is requested, the standard
cable won't work.
Warning : the card's power consumption is close to 50mA
on each -9V/+12V power rail, which is the maximum a MK1
PSU can handle according to the VCS3 MK1 users manual.
It *should* work with factory condition MK1 units but
will push this old PSU to the limits. I assume no
liability in case of problem (anyway, it can be
repaired, no worries).
An extra PSU
can be added to MK1 units to power a KS / TKS keyboard
and the Portabellabz expansion cards, here are the details.
Thick PCB for best stability and solidity
2 identical LFOs
Variable shape of both waveforms / fine tune
Hi/lo range switch
Lowest frequency : +/- 25 seconds cycle
Highest frequency : +/- 90Hz
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
2 identical CV modulation busses
Individual level pot for each output of the LFO's and
Left bus CV routed to input channel 1
Right bus CV routed to input channel 2
Mixed output CV inverter switch
2 attenuverter pins
Scale and invert signal
Fires the Synthi's envelope generator by either LFO (3
position switch 1 - off - 2)
Small plates can be mounted to the back to lock the
Spartanite case's handle for better stability.
It is possible to add a female socket onto the top side
of the Sister Card.
The card's and KS (or Kenton type Jones-jack sockets
cable) CVs are mixed passively via the 100k resistors
present on the card's CV outputs and in the KS cable to
modulate the incoming CV. Gates from the keyboard and
sequencer, from the card and from the Synthi's EG
self-retrig are mixed.
With all the card's pots set to 0 and the gate switch in
central position, the incoming CV/gate signals are not
The DIY PCB set costs 105 EUR shipped tracked.
It includes PCB, panel, Jones connector cover and handle
support (I do not supply with other parts).