[jermmd]

This has been discussed before but I can't find the answer. Is there any problem using both RCA and balanced IC's to your 2 channel amp? I'm thinking of using the RCA interconnects from my pre-pro for Home theater and the Balanced outputs from a seperate pre amp for 2 channel audio. Ideally, one preamp will be off when the other is on. What would happen if both preamps were outputting to the amp at the same time? I have a McCormack DNA 500.

[jermmd]

I think this thread belongs in The Starting Block circle. Feel free to move it if that helps.

[warnerwh]

I don't remember the answer for sure either. However I'd not do that if I were you. It seems like you need to put a switching box in so you can stay safe.

[PhilNYC]

I think you might want to check with your amp manufacturer to find out if this is ok.  I know that Blue Circle puts up big warning signs to not connect both RCA and XLR connections into the amp at the same time.   Others might have similar rules...

[SMc Audio]

Hi Jermmd -

The answer to your question depends entirely on the design of the specific amplifier. In the case of the DNA-500, the input circuit is designed so that both balanced and unbalanced signals are handled *exactly the same way.*  The XLR and RCA connectors are, in fact, tied together, so you should only use one type at a time. If you were to connect 2 preamps simultaneously via both XLR and RCA cables, you would connect their output stages together, and this is a bad thing.    You could damage one or both of the preamps. I believe this is spelled-out in the DNA-500 owner's manual - check it out.

Other amplifier designs may have switched balanced / unbalanced inputs and - depending on the exact nature of that switching - you might be able to hook-up both cables at the same time and switch between them. Always check with the manufacturer before trying this.

Best regards,

Steve McCormack
www.SMcAudio.com