[sdiy] Patchable polyphonic synth with FM or AM transmission idea

[Roman Sowa]

Frequency domain multiplexing was used long time ago in telephony.
How nice and easy solution this was can be simply put in two questions:
- why nobody remembers that?
- why it was abandonned so quickly?

I mean you have ready to use multichannel digital standards and 
multichannel ADc and DACs, why bother using an ancient idea that was so 
troublesome to manage that even 0.3-3.4kHz bandwith audio was a challenge.
And if you want full analog, I'd go with multipin connectors, there are 
lots to choose from. OK expensive patch cable then, but still a tiny 
fraction of the price of any 16-voice module.

Polysynths are hardwired for a reason.

Roman

W dniu 2018-12-25 o 20:49, cheater00 cheater00 pisze:
> Hi everyone,
> I was thinking again about how you could do a modular polysynth well,
> and it occurred to me that you might be able to use frequency domain
> multiplexing (FDM) to put several signals over a single conductor
> pair. A quick search found the Si4710 which is a bit pricey at ~$12 on
> digikey but it's a tiny 3x3mm QFN device that performs complete FM
> transmission. In a 16 voice system, at about 5 output functions per
> module, and 12 modules, you can easily use up ~1000 of those, which
> drops the price to $4. I was wondering what everyone thinks about this
> sort of scheme.
> 
> Given that metal patch cables could function as antennas and cause
> both cross talk and external signal pick up, one could also use
> multimode glass fiber and transmit signals this way. The question is,
> does anyone know whether support electronics could be found that are
> integrated enough (small in footprint) and inexpensive? The idea would
> be to build an electronics module that takes 16 analog audio channels
> and outputs a signal that can be then converted to glass media
> signalling.
> 
> Merry Christmas everyone!
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at synth-diy.org
> http://synth-diy.org/mailman/listinfo/synth-diy
>