VDX7IId - possible?

[probonopd]

Hi @chiaccona, great work! I really like your emulators.

From what I could gather, the DX7II series is using a very similar CPU. Do you think you could get its firmware to run? Its YM2604 OPS2 and YM3609 EGM chips are likely similar to the YM2128/YM2129?

I could not find something similar to @ajxs https://github.com/ajxs/yamaha_dx7_rom_disassembly for the DX7II(f)d.

I am also not aware of any existing DX7II(f)d emulation so far. I can imagine this would be of interest to many people.

[ajxs]

Hi @probonopd!
The DX7 and DX7II are fundamentally very similar. What features are you missing from the DX7II? If I recall the biggest difference in the two synths is the DX7II's 16-bit DAC and output circuit sounding much cleaner. All the other things, like multitimbrality, performance settings, etc. can be achieved by having a computer in your workflow.

Looking through the VDX7 code, it looks like VDX7 supports disabling the DX7 output circuit emulation by sending a CC message (CC#98). Maybe give that a try, and see if it sounds more DX7II-like to you.

[probonopd]

Hi @ajxs, mainly I'd be interested in having 2 voices in stereo, with the various panning effects. And the ability to run performance sysex.

[chiaccona]

While I'm pretty sure the DX7II firmware can be made to run relatively easily, as far as I am aware there is no reverse engineering available for the OPS2 and EGM, so adapting the existing chip emulation may be difficult.

As ajxs notes, the CC #98 message will switch off the 12-bit DAC (though I don't notice any real difference, maybe just my rock-n-roll ears).

The VTX816 emulator is good for multi-timbral capabilities, though it takes some patience to program voices. It can run up to 8 voices, stereo panned (and possibly detuned).