interactions of no input feedback mixing consoles

[jm56k]

Hi,

I would like to know if someone could shed some light on this :

I've tried to play with two no input mixing consoles at the same time.

So I plugged them both into a third one (say, line 1 and line 2)

I find that instead of having two independant sources that I could mix together using the third console, consoles 1 and 2 interact together, creating one interdependant signal.

So, when I change the settings of the first console, it will affect the other console as well.

I've also built a sequencer (this type of thing : https://hackaday.com/2015/02/23/logic-noise-the-switching-sequencer/ ) and when plugged into mixer 3, it behaves the same way as mixer 1 and 2, as an interdependant tool rather than a separate instrument.

Does anyone know how the signal is behaving in that type of configuration and if there would be a way to stop the interaction at some point in the circuitry ? (something using diodes maybe ?)

Thanks for reading!

[PHOBoS]

hmm not sure, what kind of mixers are you using ?

In theory if you connect a source to something (in this case a 3rd mixer) it should not affect the signal.
But I think because you are working with feedback it might be very sensitive to any noise because it gets amplified over and over.
The question is what is introducing the 'noise', what connections do the mixers share ?

[jm56k]

Hi !!

I'm using two behringer xenyx 802 and one 1002

Currently I'm using a very basic setup :

on mixer 1 and 2, control room out right goes to line 1 and control room out left goes to line 2.

Then, I send the main out of mixer 1 and mixer 2 to mixer 3 (line 1 and 2 respectively)

Also, the mixer power source is fed through transformers, so if I'm correct they don't share a common ground (so maybe some noise is induced there).

[PHOBoS]

ok, no shared power, no diy, so there's not much you can improve on the mixers themselves.
Something that could work is to eliminate the electrical connections between the mixers by using audio isolation transformers.
Transformers are bidirectional though so I don't know if this could still cause any crosstalk.


also

[jm56k]

thanks a lot = ))

I'll look into that !

[jm56k]

Hi !

So I've finally tried that audio isolation transformer solution and sadly it doesn't change a thing. *

If anyone has another idea, I'd be more than grateful!

Cheers

* I've actually used a palmer dacappo re-amp box, but it does contain such a transformer I believe