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Ivan Petrov

More CV outputs - how?

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Hi!

I'm ok with DIY'ing but bad at modifying especially software. Can AOUT modules somehow easily be cascaded? There's some old 64 out version but with no MIDI in http://www.ucapps.de/mbhp_shx8.html and not in production parts.

If 80's synths has dozens of CV's inside with their relatively weak hardware so can we have at least 64 CV out with MIDI in (and better if modulation capabilities stay) MIDIbox?

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Hello

Welcome here !

 

IIRC you can chain 4 AOUT _NG (12bit TLV5630), meaning 32 analog out, but core are small now, you can have two (even linked in the same box) for 64 CV out

Most 80' synths (for those I know) use multiplexing and low def DAC, not realy comparable with modern DAC

Best

Zam

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32 is far better than 8 (it says "limited to 8 CV output channels maximum" in both cv1 and cv2 descriptions) but where can i get info about this? Is it supported by existing software?

Actually for control them use demultiplexing of single DAC which is not so bad - precise multichannel DAC's are still costly compared to mux/demux chips but is's different software approach i suppose. So we can theoretically use MCU's DAC or one external DAC with old 4051 demuxs (or something newer) for cheapest solution - if it worked ok in all that 10000$ VCO poly legends with 8080 CPU inside it'll work even better on modern hardware. But this if somewhat different hardware and software design...im totally inpacable of such level of engineering. So i started with searching easy way to cascade existing AOUT's - still cheaper than commercial converters. I want to build lagre analog modular system but totally sick of building tons of analog modulation and sequencing sources in 2019. Cheap CEM's back in production motivate me even more and i want recreation of VCO poly's too but need appropriate control. There's good commercial solutions but too pricey for me the third world poorman.

Basically 8 outs is ok to build something multitimbral or 4 voice poly but i suppose it so easy expandable by more qualified people so i ask for help. :)

BTW open-source MIDIbox holds third place in MIDI-CV control for large systems even with 8 outs (but with polyphony and internal modulation). First i think is Expert Sleepers FH with up to 64 outs and second is EDV MUC-800. So we can be first place and still open source with some mods.

Edited by Ivan Petrov

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Hello

 

5 hours ago, Ivan Petrov said:

32 is far better than 8 (it says "limited to 8 CV output channels maximum" in both cv1 and cv2 descriptions) but where can i get info about this? Is it supported by existing software?

I'm talking about AOUT_NG

http://www.midibox.org/dokuwiki/aout_ng#the_pcb

Have a search in the forum, someone do the test times ago and it work (MB_NG)

You have to chain the TLV at DOUT pin and enable 32CV at .ngc file configuration (supposed you run MB_NG on a stm32F4)

Best

Zam

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Found alot to read thx!

Maybe 32 not a limit, but that DAC's too expensive though. Need some experiments with lame copy-paste engineering from existing http://www.ucapps.de/mbhp_shx8.html version with demuxing maybe...lol. I hope someone experimented with this and will post here - it's so easy for qualified ppl as ADC muxing at which MIDIbox is very strong.

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