Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: nyu notesfiles V1.1 4/1/84; site rocksvax.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!ihnp4!houxm!whuxl!whuxlm!akgua!sdcsvax!dcdwest!ittvax!decvax!genrad!panda!talcott!harvard!seismo!rochester!rocksvax!dave From: dave@rocksvax.UUCP Newsgroups: net.music.synth Subject: Re: MIDI Message-ID: <26500002@rocksvax.UUCP> Date: Tue, 26-Feb-85 21:12:00 EST Article-I.D.: rocksvax.26500002 Posted: Tue Feb 26 21:12:00 1985 Date-Received: Sun, 3-Mar-85 02:59:04 EST References: <3416@alice.UUCP> Lines: 17 Nf-ID: #R:alice:-341600:rocksvax:26500002:000:835 Nf-From: rocksvax!dave Feb 26 21:12:00 1985 Opto-isolators are the best things to use when you want to electically isolate signals. Most musical equipment tends not to get grounded very well and you can end up with a healthy current flow through the grounds on your signal lines. These lines tend to be small gauge and can easily build up volts of ground loop messing up the signal, not to mention the potential of electrocuting the musician, and/or frying the instrument. While not strictly necessary a side benefit is it easily converts currents to voltages and give you about 2000V of isolation in a little package. You could always use a plain op-amp as a current to voltage converter, but I suspect that it costs the same The opto way giving you as a bonus this isolation benefit. Dave arpa: Sewhuk.HENR@Xerox.ARPA uucp: {allegra,rochester,amd,sunybcs}!rocksvax!dave