[A6] A6 Main Output Impedance

[Michael E. Caloroso]

> >> could anyone tell what impedance the A6 has on the main outputs?
> >> I want to make a cable for a balanced inputs mixer. So I need a suitable
> >> termination resistor for the cold pin on the A6 side of the cable.
> >
> > I don't know what the output impedance is, but termination resistors are 
> > used for long length cables (hundreds of feet) carrying high frequency 
> > (Mhz) signals.  They are used to prevent reflections back up the signal 
> > cable which can degrade radio or TV signals.  Signals in the audio domain 
> > do not suffer from reflections like high frequency signals do.  Seems kind 
> > of overkill.
>
> Hi MC,
> 
> I just want to balance the cold pin in respect to the hot pin.
> To get optimal noise rejection, the cold cable conductor has to be 
> terminated at the source side similar to the output stage impedance of the 
> unbalanced source (A6 output). So the hot (connected to the source) 
> conductor and the cold conductor (connected to ground thru a resistor at the 
> source side) receives same amount of hum and noise, that gets canceled in 
> the balanced input stage of the mixer.

Ah - that makes sense.

Nothing in the A6 manual, I'm afraid you'll have to measure the output impedance.  Have you tried to email Alesis?

MC