2. amps-preamps
  3. 166076-3592

hum when hooking up sub to preamp

I have a Jolida Fusion Preamp and it's kind of noisy. It does have a musical full bodied sound which I like. I am hooked up to a Parasound A21 which has gain knobs. I have the gain knobs dialed back about a 3rd and this eliminates the hum to where you can only hear it from several inches away. When I hook up a sub from the XLR on the Jolida now there is hum coming from the main speakers again. I guess my question would be is there some kind of on way transmission xlr or rca cable where the noise would not travel back into the preamp? Would this even help. Any other suggestions to get rid of the hum here? 

Thanks
mofojo

Showing 2 responses by oldhvymec

oldhvymec
5,101 posts
 
Have you swapped XLRs? 

Have you turned down the gain on the Parasound, all the way. I read in one thread, with the gain turned UP it was causing an issue. When turning it all the way down, it cured the problem.. I think it was a pop issue or might have been noise...

Do you have the gain set real HIGH on the sub plate?

Is there a switch to flip and it's in the wrong position for RCA, XLR?

Do you have a single ended RCA to try? Makes me wonder if the XLRs are truly balanced and have hot/cold noise canceling.

Regards


oldhvymec
5,101 posts
 
Wow.. you said you turned the gain down and the noise went away?

There is enough gain without the gain turned up on the A21, isn’t there?

The same circuit or at least rail at the main will help, too for future noise.

No need to start making more noise. :-) You'll get it..
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