[LAU] Galvanic isolation (was: Re: pianos with built in recorders?)

[Yves Guillemot]

Le jeudi 24 décembre 2015, 11:48:07 Bob van der Poel a écrit :
> I believe that the MIDI spec
> 
> http://www.midi.org/techspecs/electrispec.php
> 
> says that you must have a opto-isolator. Devices without one are probably
> not compliment ... don't know about direct usb connections.
> 

MIDI uses an unipolar signaling which is very sensitive to electromagnetic 
noises, in particular those ground loop generates. That's why MIDI standard 
requires an opto-coupler. 

USB uses a differential signaling and can works without any galvanic isolation.

-- 
Yves Guillemot