[sdiy] USB/MIDI ground isolation?

[cheater cheater]

He means usb over midi. not a usb-midi interface, just a USB cable
which connects straight to the keyboard or what ever it is. MIDI is
transferred over that usb cable, there is no other physical transport.

USB capable opto isolator parts are not that expensive.

Isn't ethernet galvanically isolated? (if so - how?)

That would be one more reason to go OSC

D.

On Thu, Sep 17, 2009 at 7:00 PM, Manuel Odendahl <manuel at bl0rg.net> wrote:
> Hi,
>
> On Sep 17, 2009, at 7:54 PM, Neil Johnson wrote:
>>>
>>>  It seems to me that USB/MIDI has dropped the best feature of old
>>> fashioned MIDI.
>>
>> Yes, because its cheaper. MIDI over USB is a cheap hack designed for
>> low-cost consumer devices, where cost is more important than audio
>> integrity.  If you want to break the ground loops there are several ways,
>> from USB opto-isolators (very expensive), audio transformers (mildy
>> expensive) to cheap tricks such as ground-lift with a lowish-value resistor.
>
> Am I missing something here? On input, inside the USB/MIDI adapter, there is
> an optocoupler like you would expect. On output, the wires go straight
> through into the optocoupler at the receiving end. Thus, every connection is
> isolated. I don't really understand what this thread is about?
>
> Regards, Manuel
>
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