SIEL EXPANDER EX80 SN 04325

Note: Auction links are affiliate links for which the site may be compensated.
via this auction

"Siel Expander 80 Synthesizer
with RAM cartridge and dual output power supply.

Fully functional in very nice condition for a vintage 80's synthesizer. See the pics for the cosmetic details. It comes with the rare RAM cartridge, which is essential as it gives you 50 user slots for your patches, since without it you would only have 10 since the first 40 patches are presets. Also, it comes with the real deal power supply, which is from a DK80 keyboard, as these were designed to run off the keyboard power source and typically did not come with a power supply.

The Expander 80 is an 8-voice (DCOs) polyphonic synth with one 24dB SSM2045 filter, which does sound nice and similar to the SSM2044 found on other vintage classic synths (eg, PPG Wave, Korg Poly-6 Mono/Poly). To get more info, since I can not paste links into the listing, do a search for "Siel Expander 80 Resource", which will give you all the details. For example, surprisingly on this synth, the parameters are adjustable by Control Change messages. I tried it out with my E-MU X-Board and it worked great, just assign the CC number to a knob and tweak away. Also, it describes and adjustment to increase the resonance, which I have not done myself. However, from the way the filter sounds to my ears, it sounds like it was likely adjusted from the previous owner. Feel free to check yourself, if you can further improve the sound of the filter from where it's at now, this synth is going to sound fantastic because it sounds great as is, especially in the stacked (double oscillator) voice mode. Let me know if you're interested in a demo as I can quickly put together one, and it will give me an excuse to play with this synth another time before it's gone."