CatSynth Pic: Gracie and Oberheim OB-Xa

Gracie is back and performing her duties as the quality manager for Synthetic Dreamscapes.

This Oberheim OB-Xa is not totally rebuilt yet, but our Quality Manager just had to get in on the action early!

The OB-Xa is one of the classic Oberheim analog synths and was featured in lots of early 1980s synth-heavy pop music. For me personally, it would probably be more interesting to have the SEM filter to complement the other instruments, but it still has a sound that would be instantly familiar to fans of this era.

The OB-Xa is a massive analog synthesizer with a very familiar and classic Oberheim sound. Its sound, size and power are very similar to the Prophet 5 from Sequential. However this one has up to 8 voices which can be split, layered and stored!

The OB-X was very similar to the OB-Xa except that its voices could not be split or layered and, more significantly, the OB-X had a lowpass-only discrete SEM 12dB/oct state variable filter, which had a great and classic Oberheim sound. The OB-Xa changed that in an attempt to economize manufacturing and increase stability by switching to CEM3320 Curtis chips for its filters. The Xa offered two switchable filter modes: 12 dB/oct (2-pole) or 24 dB/oct (4-pole). This hardware change resulted in a more agressive sound, not quite as creamy as the OBX original, but what still became a “bread and butter” sound of the Oberheim line.

Vintage Synth Explorer: http://www.vintagesynth.com/oberheim/obxa.php

CatSynth Pic: Gracie and Korg Poly 61

Gracie is back, this time with a Korg Poly 61 synthesizer. From Alsún Ní Chasaide (Alison Cassidy) of Synthetic Dreamscapes, who repaired the instrument.

This unusual Korg Poly-61 with factory MIDI retrofit (not Poly-61m) is finally finished and working perfectly. As usual, the last 20% takes 50% of the time!


In this case, the non-working panel buttons were traced to severe oxidation around two connectors on the MIDI board. Both pin headers *and* connectors had to be completely replaced / rebuilt for this to be long-term reliable. Also, one new rubber key contact set was needed, and Andrej’s new CPU board from yesterday.


And after a tune-up – perfect!! Ready to go back to its local owner 👍🏼😊

Gracie is the Quality Engineer for these repair projects 😸🎹

CatSynth Pic: Gracie and Vintage Synths (Oberheim, PPG, DK Synergy)

Gracie returns with an impressive collection of vintage synths, including multiple Oberheim modules, a PPG Wave, and a Synergy.  

From Alsún Ní Chasaide (Alison Cassidy) on Facebook.

How does she even get up there??

You can see Gracie’s many appearances on CatSynth via this link.