I should say first that this is not finished, but it is in a state that can be shared and I invite comments and contributions to help with the last few bits (details below).
I’ve never attempted anything like this before. If I’d known what was going to be involved I may never have started it, but I’m glad I did - I’ve learned so much during this project.
TBH I started out by recreating the main board with PatchMaster and that was going to be it. What can I say - I’m a graphics guy so recreating the look should have been enough. Then a little voice kept whispering - how hard can it be? It’s just a few faders and switches after all.
I did a deep dive into the User Manuals, signal flow diagrams and videos that explained what all the controls do. There’s a series of eight videos by Marc Doty which was particularly helpful (starting with no2 because the first one is just an introduction really).
I have no illusions that this will sound exactly like an ARP Odyssey (VCO choices were limited due to the frequency range and the necessity for Sync), but it should work like an ARP Odyssey.
A lot of the faders have min/max parameters set to give the range of values required. There are one or two VCAs in the signal path to enable scaling of these controls. I may add more.
I added a couple of Tuners to the left of the Main Board because the VCOs centre on 200Hz and not middle C or anything obvious. Middle C is 0.558 on these faders. Oh and I added a couple of Presets which may give you an idea of the range of sounds possible, and I will add more (feel free to contribute to this also).
There are a couple of things I haven’t worked out yet;
- The KBD Gate / Repeat etc switches under the ADSR, and
- Duophony. Yep this is not merely a monophonic synth, in some circumstances you can play two notes at once. " One key pressed (monophonic) - only CV1 is sent. Two keys are pressed (duophonic): lower key sends CV1, higher key sends CV2" I have actually got this working (kind of) but I can’t get it to do it automatically. I may have to add a button to activate this feature.
I need to say a big Thank You to @stoermelder for the 8Face module which enables the presets, and for fixing the bug in the GOTO module which I have used to skip from place to place in the patch.
Also Thank You to Nysthi for the BZ Envelope module which was the only way I could get the Proportional Pitch Control to work.
Test Patch for the Duophony function;
ARP Odyssey Development Patch.vcv (65.5 KB)
