Since I’m in the long process of making a MIDIbox SID step C (and redesigning the front panel), I’ve thought about accomodating some future extensions now - some that I might add and some that are still floating around in TK’s head
I’m anticipating some kind of analog output (to control an external filter, volume control, panning, etc.).
Is this going to involve one MAX525 per core, so that each core (in a multi-SID setup) can modulate up to four analog outputs? Should I therefore add another four rows to the modulation matrix?
Or is this overkill and I should only add one row and use CORE:J5 to drive my own quick’n’dirty 8-bit parallel DAC?
I know this is FAR ahead for me (still in panel design/construction phase) but I’d like to have my panel design accomodate the extensions…
a more general answer: since one month I’m working from time to time on a new SID release, some of the new features are suggested by Jess D. Skov-Nielsen (an experienced sound designer with a lot of SID knowledge).
Here a list of functions which are already implemented and tested:
optional oscillator phase synchronization for more percussive sounds
non-linear envelopes with flexible CURVE parameter which allows you to bend the attack, decay and/or release curve to upward/downward direction
optimized linear response of the 8580 filter
correctly calculated Note->frequency table
more stable wavetable sequencer timings (based on experiences with MIDIbox SEQ)
optimized display handler to avoid long delays of more than 1 mS
minimal AOUT support (7 CV out assigned to the existing outputs of the modulation matrix, 1 channel to the filter resonance parameter
What I plan to implement after MIDIbox SEQ has been released:
7 dedicated modulation matrix outputs especially for the CV outs
note/pitchbend assigned to the 8th CV out
1 Note gate and 1 sequencer clock out
a special button combination which switches the LED matrix of the control surface between common and AOUT matrix — I will never change my own panel anymore, therefore this solution
a second MIDI channel to control the AOUTs via MIDI
The last point requires some conceptional changes (internally), therefore this effort can only be made by myself (I know how, but I guess that the implementation and testing will take at least 2 days) - on the other hand: the current solution already works very fine. You can connect an analog filter to the SID and control it with the filter out of the modulation matrix (the SID filter should switched off), or you can use the three PW outs of the matrix when only saw/tri/noise sounds are played, and/or additionally the pitch outs when oscillators are disabled.
But this solution won’t be compatible with the planned one, therefore I haven’t released it yet.
Btw.: the AOUT module gives me the possibility to display the envelopes - it was a very useful debugging feature
a special button combination which switches the LED matrix of the control surface between common and AOUT matrix — I will never change my own panel anymore, therefore this solution
Well if you’re never changing the panel, there’s no need for me to add any buttons/LEDs/encoders since they’ll never get used in any official SID release. I’ll post a design concept soon for some expert feedback
hey, before i get building more sid modules…will theese changes require new boards? or will you use an expansion board? or do you only chnge the software? ( i know the aout will be a separate board.). thanks and great job, now i am even more excited…(like that’s possible?)
no, it’s just a software enhancement. No additional core module is required. In difference to the original AOUT schematic the module has to be connected to pin RC.0, RC.1 and RC.3 (J6 of the core module)
Can you publish a schematic (or at least chips I should bundle with my Maxim order) for getting the -12V DC supply from the MB SID supply (C64 PSU or 15v DC transformer)?
like already mentioned somewhere else in the forum, the AOUT circuit is stable, I will maybe add some caps (although they are not really required, but just to improve the quality), and I will add an additional port to the upcoming AOUT_MUX module before starting with the layout (AOUT_MUX won’t be supported by MIDIbox SID!)
