Oberheim OB Xa - the monster for deep, fat, dark analog tones

video upload by Sergio Man

"The Oberheim OB-Xa is an absolute monster for deep, fat, dark analog tones—perfect for haunting drones, growling basslines, and eerie pads. Here’s why it stands out:
Why the OB-Xa is Perfect for Dark, Fat Sounds:

🔥 Oscillators – Two massive CEM3340 oscillators per voice, capable of thick detuning, deep PWM, and sinister saw waves.
🔥 Filters – The Curtis low-pass filter (12dB or 24dB) gives it a dark, creamy, and moody resonance. When pushed, it can create growling basses and sinister sweeps.
🔥 Unison Mode – Stacking all voices together creates earth-shaking, monstrous basses.
🔥 LFO Modulation – Slow, deep LFO modulation can bring ominous movement to pads and leads.
🔥 Vintage Drift – Since it's full analog, slight imperfections give it that organic, alive feeling—like a demon breathing in your mix.
Dark Sound Design Ideas:

🔊 Evil Bass – Low-pass filter, resonance at 40%, slight detune, Unison mode.
🌫️ Cinematic Drone – Slow LFO to filter, subtle PWM, a bit of white noise.
🔔 Haunting Bell Pads – High resonance, slow attack, some reverb and delay.
⚡ Aggressive Leads – 24dB filter, medium resonance, quick envelope decay for punch.
Similar Dark & Fat Synths

OB-X8 (2022) – Modern reissue, true to the original OB series.
Sequential Prophet-5/6 – More aggressive and raw, but in a similar analog spirit.
Moog One – Thicker and darker but with a more modern feel."

Automat and the ASE MCS70

Another via Frederic. Automat is an old electronic album from 1978 that featured the ASE MCS70. You can read more about the album here where you will find a number of samples. You can find more on the MCS70 on Synthmuseum.com where the image below was pulled from.

via the Automat page:
"When I saw my incoming mail box in 2000/October/01 I had a great surprise. A message from Mario Maggi (the man who idealized and constructed the MCS70, the sinthesizer used to do "automat"). Once again, my thanks to Sergio A. Simões. He found the Mario Maggi´s e-mail, contacted him, and told him about my page. To receive a message from Mario Maggi and all creators of "automat" is one of my great objectives. Naturally, I had (and still have) thousands of questions. We change a few messages, and I´ll continue changing. Now you can see a few questions. The first message was from Mario Maggi to answer questions for Sergio. The main subject is about MCS70, but there is a lot of information regarding 'automat'." Thanks Frederic!