Journal 2025-05-04
Published: May 4, 2025
VCA
All "IC" (silicone filled mini PCBs) schematics are available except for the VCA. Both 700 and 770 schematics have a non-IC version of the VCA.
Mini 700 inspired isolated VCA http://jhaible.com/legacy/additional_schemos.html http://jhaible.com/legacy/jh_720_vca.gif
Some more info: https://web.archive.org/web/20250304000936/https://www.asahi-net.or.jp/~wz4k-tnk/MY/korgvco2.html
Annotated 800DV schematics: https://www.cykong.com/Synths/Korg%20800DV/Images/Korg-800DV-Schematics-Coloured.gif
The VCA circuit could be isolated either by knowing what's going on or by comparing 700, 770 and 800DV schematics and seeing how the IC ties in. The jh720 VCA could help here since I know nothing about VCA circuits.
Case
I found a case for 60 Euros shipped that has roughly the same dimensions as the 800DV. For that money I couldn't build it myself. The case was intended for a Poly 800 with a vocoder add-on but the project was never finished by the original owner. This definitely saves me a lot of time and money.