Speaker hum.

Hum travels to opposite speaker when I switch xbr cables from HCP to GCA 250. Have turntable and cd inputs any ideas. Thanks. The GCA 250 is new.

Forgot to mention, I get hum through turntable and cd player…seems not device specific.

About the only thing that I can say at the moment is that the GCA-250 is largely exonerated by your test. The problem could be with one of the cables having a bad ground, or something in the HCP. More testing is needed, but what exactly I cannot say without more details.


nimbus109 said Forgot to mention, I get hum through turntable and cd player...seems not device specific.
Can you be a bit more specific about the nature of the hum and the rest of the system connected to it?

The hum gets louder as I increase volume. I have disconnected turntable and cd player with just the HCP and gca connected through new xlr cables. When I switch xlr connection points, the hum travels to other Legacy Focus speaker. Strangely tried to use rca cables for amp/preamp connection and get no hum and when I connect an input, no sound. Could it be a dirty wall outlet or something on the line causing interference? Thanks for any advice.

I can only hear the hum when I crank it up to 11, or in non Spinal Tap around 50 which is far beyond the comfort level of these old ears. Cannot hear a hum until I approach 50 with the hcp.

If I remember correctly, wasn’t there a switch on the back of the GCA for RCA/XLR? Maybe you didn’t click that and that’s why?

I am uncertain was a HCP is.

Sorry pca-2 one of yours.

OK, the preamp. No problem. Do me a favor. Can you follow these two tutorials closely and report back with your findings?


If the simple test doesn’t yield results, go here:


Let us know.

Installed a dedicated line from the sub box. All is silent.