On Wed, 23 Dec 2015 17:42:29 -0600, Jonathan E. Brickman wrote: >> USB MIDI has got the risk to cause noticeable MIDI jitter. >> >> Does USB MIDI provide galvanic isolation? Several times I read claims >> that USB MIDI connections aren't galvanically isolated. >> >> Standard MIDI connectors make usage of opto-couplers and shield of >> the MIDI DIN connectors is open. >Certainly all of the USB MIDI connections I have ever tested, are not >galvanically isolated; I always get trouble with USB signals bleeding >over where they don't belong. USB-to-DIN adapters I have used have >been better, but not perfect. Is there a make/model of USB-to-DIN (or >even PCI-to-DIN if it exists anymore) which you know for sure has >opto-coupling? That would be a great boon to me. Sooner or later I'm >going to do optocoupling for audio too, probably using a TOSLink setup. You can solder yourself or buy cables for serial port, resp. PCI sound card output with such a connector, that have build in opto-couplers. I remember this very good, because years back, when I started needing reading glasses, but didn't own them, I tried to resolder a a self made parallel port cable. I tried to add opto-couplers and due to the missing reading glasses, resp. a missing magnifier, I damaged the jack. The cable worked without opto-couplers for my serial port, but didn't work for my Envy24 sound cards. I then ordered a cable for around 10,- € with build in opto-couplers. I own USB port to MIDI DIN, but never measured if shield is open and can't take a look inside, but I didn't experience electric noise caused by the USB to MIDI DIN cable, just jitter. My RME PCIe card has got break through MIDI DIN. I don't know if inside the connector or on the board are opto-couplers, but there are no noise issues caused by MIDI connections and there are no level issues. Discounter keyboards don't provide MIDI DIN connectors anymore, they provide USB MIDI only -- http://www.grundgesetz-gratis.de/ _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
