[sdiy] LED current source needed for 'digital' outputs?

ASSI Stromeko at nexgo.de
Sat Mar 8 14:08:50 CET 2014

On Wednesday 05 March 2014, 14:26:47, Florian Anwander wrote:
> Am 05.03.2014 02:06, schrieb Michael Zacherl:
> > reading that thread and thinking of a flashy MIDI-controller and an
> > USB-audio interface connected to the same bus makes me wonder how
> > better usb-audio products manage to stay relatively silent.
> My experience is: They don't manage it. As soon as the interfaces are
> USB-powered you will suffer a lot of digital noise via groundloops much
> likely.

It actually doesn't matter if it is USB powered or not.  The problem is the 
groundloop created by the DC-coupled signaling of USB and nothing else.

> In our live impro-project we have forbidden USB-powered audio
> interfaces.

If you don't need highspeed USB, just use USB isolators (or more traditional 
DI boxes at the audio I/O, but USB isolation is cheaper if you have more 
than one I/O).

+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+

SD adaptations for KORG EX-800 and Poly-800MkII V0.9:

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