cd player - xlr output buzzing

Check and see how the adaptor is wired. Sometimes if pin 3 is left floating, the result is a buzz. So the adaptor should have pin 2 tied to the center pin of the RCA, pin 1 of the XLR tied to the RCA ground, and pin 3 of the XLR tied to pin 1 of the XLR. That should sort it out.

hmm how do i do that? it is an actual 1m long cable, do i need to open it up somehow?

My guess would be that your adapter cable already shorts pin 3 to pin 1 (most xlr-to-rca adapter cables and adapters do that). And I would further guess that the reason for the problem is that the cd player, which has a low 22 ohm output impedance, cannot tolerate having its "cold" output signal (xlr pin 3) shorted to ground, with the only current limiting being provided by that output impedance.

Using an adapter plus an rca-to-rca cable would be no different, electrically.

I would suggest asking the cdp manufacturer if the player can tolerate having xlr pin 3 shorted to ground.

Shorting one side of a balanced input to ground via an adapter would not be a problem, but I would avoid doing so with any output unless the manufacturer confirms that it is ok, and/or the output impedance is known to be considerably higher.

To answer the question in your preceding post, the wiring configuration could be checked with a multimeter or ohmmeter.

Regards,
-- Al

Thanks Al - the difficulty I'm having in finding any consistency to testing the problem is that when it is connected to the preamp, the buzzing is only at low volumes and sometimes even disappears after a minute or two.

When I use the exact same connection/cable to a Vincent KHV-1 headphone amp, there is no buzzing detectable at all. This would indicate that the cable is possibly fine, but there is something the preamp is disagreeing with?

"there is buzzing and harmonics in the speaker output at low volumes."

"It is okay at higher volumes."

It sounds a little like a ground loop and this may be the smoking gun

"The only reason I don't use the RCA output is that it runs directly to another amp/system and the RCA cable is far longer than the XLR->RCA cable.

If the other >>"amp system"<< is in another room ... it is probably plugged into an outlet that is fed from the opposite side BUS in your main panel box that your main system's outlet is fed from

Main system and preamp plugged into outlet fed from BUS A ... other amp system in the other room plugged into outlet fed from BUS B ...this will create a ground loop

Try disconnecting the RCAs that feed the "other system" in the other room from your preamp and see if the noise goes away