Amplifier Damage

All good @rman9 

I inadvertently hooked up a second preamp output to another devices RCA output.
Our courser the speaker went pretty quiet as one source was driving 0v and the other signal, so you get a voltage divider.

But they are made to do that, or the poutoput impedance would be s closer to 0-ohms, that t50, 500, or #k ohms.

(Probably also why people with high output impedance have more cable effect than ones using a lower output impedance preamp.)

I would not fret, but it is better to ask Luxman as they know their stuff more intimately.

I’ll look forwards to seeing what they tell you.

Can anyone further clarify on this issue? 

This sounds like something I have done in the past. If I am breaking in a new component, say a preamp for example, I wouldn't turn the amplifier on when not listening. I would just let the preamplifier continue to play.  

Similarly my Pass preamp is on all the time while my Pass amplifier is on standby. Is this a potential scenario where the amplifier can become damaged? 

How would one run something out of the tape output? Say for example a headphone amp. You couldn't listen to one over the other without disconnecting? 

An amplifier's input stage can be overloaded by a bad upstream component which has too much voltage. 

A preamp with too many outputs connected may no longer perform correctly as the impedance becomes too low.  It is rare that shorting a preamp (impedance = 0) would cause damage but theoretically possible depending on design.  Usually the output impedance of a preamp is high enough that it is self protecting.

Okay guys, I was just on the phone with Luxman service.. It's all good, every Luxman component has relays in the Input and Output stages. That's the clicking sound that you hear when you select and deselect input and output options. So when the 550AXII is in stand by mode, the input relays are disconnected. So what ever signal I presented at the input is not passed through. And the D03X is designed to be active for both Unbalanced and balanced output at the same time. They suggested I could experiment turning on and off one of the equipment to see if it makes any difference in the sound of the one still connected. Although, they said it is safe to try that.. I am not venturing that route.. When I get the C900U in a couple of weeks, I'll have these separate setups.. Hope that helps..

I recently rewired my tube amp and now have two inputs, one balanced with a transformer input, and one RCA.  I put in a selector switch.  

Currently I have both RCA and XLR hooked up to my preamp so I can select and listen to one and then the other for AB testing.  I think this is similar to what you are reporting with your luxman, When one input is selected, the other one is disconnected.  Non problem.

Jerry