I find the original SID filter to sounds wack, and I’m interested in building a Moog filter to reach more interesting sounds.
I know I can control it using pots/knobs but I would like to control it remotely by midibox sid (like we can control the internal sid filter)
and now, only I have in my mind are questions
What is the simplest way to add a external filter to a midibox sid so I could control it the same way I control the internal SID filter ? (I mean - automatation - so I could make patches)
I know that the params of internal SID filters are controlled using midi CC commands, so how could I control the external filter params ?
(not only by it’s [filter’s] knobs but also by midi commands/events)
I was reading something about DOUT and AOUT and CV outs but I don’t fully understand the topic since I’m new to “MIDI world”.
Could someone put it out clearly, cause I think I’m not the only one who would be interested in having a external filter working with midibox sid.
P.S.:Digital pots like the suggested one from Alekx are another posssibility. But I think CV is more flexible because nearly every type of analog synth gear uses it.
you could make the low cost aout (search forum) but you’ll have to make it on breadboard (no pcb yet), and i don’t think you have to build MBCV; you can connect AOUT to MBSID if you configure it?
no description how it works or any other documentation, could anybody explain to me
how to control this ?
thats not true, you only have to read the ChangeLog of MBSID:
o experimental AOUT support (7 CV out assigned to the existing
outputs of the modulation matrix, 1 channel to the filter
resonance parameter). For the final version it's planned
to integrate the AOUT into a seperate modulation matrix,
and to add new CC's to a seperate AOUT channel
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For your specific usecase it means: you can control the external filter with the same CCs/LFOs/ENVs, which are assigned to the internal SID filter (this filter can be switched off). Improvements are planned, but it can take some months, since they require a new PIC (with more memory - PIC18F4620), which is currently not usable due to a silicon bug (see MIOS ChangeLog)
However, this doesn't mean that it wouldn't be possible to control external filters --- and in my oppinion, the current implementation is already very powerful (in the meantime I don't use the MBSID without external filter anymore)
There is also a new beta version available (see MBSID board) which provides an alternative "low-cost" AOUT module, see changelog of midibox_sid_v1_7_303beta9:
[code]
o "ENABLE\_AOUT 2" selects a low-cost AOUT module
(currently it only outputs CutOff as 12bit value, once I got
the Curtis chips I will do some experiments with 8bit CutOff
and 8bit Resonance)
