Wowwww… I have been wanting to do exactly what you’re doing for a long time. I have a Sequential Six-Trak and I think the 3394’s sound so nice, but its Z80-based implementation is so limiting by today’s standards - slow envelopes and coarse resolution on controls.
I could check the voltages on the VCA pins if you like to figure out what the chips are getting in the Six-Trak. Might take me a few days to get to it though, so let me know!
I have made a similar box with PSU, 4xAOUT_NG boards, 4xSSM2044 boards and 2xSSM2154 boards and experience the same problem. I have intended to ask about this too, but you beat me to it. I can change VCA level ful range via level setting in the MB SID, but if I route EG 1 or 2 to level and set it to full depth, I still cannot get full range amplitude modulation. I don’t remember if I have tried this with the LFOs.
Wow! I have the similar problem with CEM3379 in my MBSID V2. Perfect control (I use AOUT modul) VCF section (cut off and resonance control is ok), but problem with control of VCA section of 3379. I can change VCA voltage via menu parameter “volume”, but I also try to route EG on VCA via matrux - no result :poke: . Whats wrong? :unsure:
Wow! I have the similar problem with CEM3379 in my MBSID V2. Perfect control (I use AOUT modul) VCF section (cut off and resonance control is ok), but problem with control of VCA section of 3379. I can change VCA voltage via menu parameter “volume”, but I also try to route EG on VCA via matrux - no result :poke: . Whats wrong? :unsure:
If you don’t get anything out the VCA, did you set the depth parameter of the EG or LFO? Anyway it seems the output range of modulation of volume if not as it should.
There are two depth parameters: one for the ENV depth, another for the modulation depth (in the modulation matrix).
Both are set to 50% by default - I guess that you forgot to set the modulation depth to 100% (128)?
Again, CFG -> VOL works perfectly. If i set an external filter (After SID but before VCA) in resonance I can adjust the volume with this setting, so I am 100% sure the VOL setting is forwarded via AOUT to the VCA.
Then, in the modulation matrix, I assign one modulation source to VOL and set the depth param of both the EG/LFO and the modulation to 127. I doesn’t matter if I use EG or LFO, same result. Only about 50% modulation range. Only half range if I use negative depth too. There must be some setting I am missing…
I am pretty sure the AOUT channel for the VCA module is configured in unipolar mode plus it works fine when controlled from the CFG -> VOL menu. I don’t think it is that module. It must be something in the software.
19]An envelope doesn’t sweep through the whole value range: yes, this is true if only the ENV depth is set to maximum level (+127). With the default configuration of the modulation matrix, this will result into a quarter of the available value range.
E.g. if the filter cutoff is set to 0, ENV depth set to 127, the filter will only sweep between 0%..25%. Same for volume.
In order to sweep through the whole range, the modulation path parameters have to be changed:
enter the MOD page
select MOD 1 (if not already done) for EG1
you will notice, that EG1 is only assigned to Sr1 - assign it also to Sr2, and ensure that the “1+2” operator is selected
-> this will double the ENV level
in addition, set the Depth parameter of the modulation path to 127 -> this will double the MP level
As the result, you will get an envelope which sweeps through the whole value range from 0% to 100%
[20]The AOUT channel is always at maximum level when the V2A option is used: because the volume parameter in the CFG page sets the offset for this AOUT routing option. Change the volume to 0 to set the offset to 0V (similar to CutOff)
Changing Volume 0-127 sweeps aout volume channels from 0 to 5v.
All 8 AOUT voltages can be changed from 0 to 5v with EXT menu.
When i’m routing ENV2 to volume as on picture i have next behavior:
After note on Volume CV rises to 4.37v and remains constant after note off. It can be changed it with Sustain level in 1.86-4.37V range, also with Envelope depth [0-127] in the same range.
So VCA stays silent only untill some notes played.
