Rockman Stereo Chorus and other modules

Yazoo55 · Post by **Yazoo55** » 17 Jul 2022, 13:42

A lot of people really like the old Rockman modules. They have been out of production for a long time now yet there are no schematics available. I understand the US patents expire after 20 years so they would not now be covered (?). Looking at pictures of the stereo chorus pcbs, it looks like it would be possible to clone it and I would love to have a go but without an accurate schematic it would be a world of pain. Has anybody else tried this?

VivMeLol · Post by **VivMeLol** » 01 Aug 2022, 15:46

There are two possible approaches :

A) Trace the originals and replicate it
That would use ancient BBD with their noise and distortion issues + price and unavailability issues

or

B) Create a digital circuit using modern parts, that does exactly what the originals did

But with lower noise, lower price, lower component count
and the ability to run other algorithms besides the Rockman ones

Yazoo55 · Post by **Yazoo55** » 16 Dec 2022, 14:34

I went ahead and traced out the Stereo Chorus Module in Kicad and built it. After a bit of a scare over a faulty chip, once I replaced it it all worked. I’m both pleased and relieved.

There is a dedicated Facebook group called “Not just another Rockman group” with all things Rockman. I’ve posted pictures there.

thpmink · Post by **thpmink** » 16 Dec 2022, 18:19

Unfortunately that group is private. Can you share the pics here too? And do you have a schematic? Thanks!

Yazoo55 · Post by **Yazoo55** » 16 Dec 2022, 20:15

I will try to upload an image. It’s been a while since I did this and I’m struggling. I’ll try again.

If you pm me, I would be happy to send you pdfs of the schematics. I won’t win any prizes for elegance though!