Humming from RMB 1075 after RSP 1098 purchase

[teekster]

I just picked up my new RSP 1098 2 days ago (replacing my RSP 976 pre/pro). I notice a humming sound from all channels driven by my 2 year old RMB 1075 amp. A am driving the center and surrounds with it. My main speakers are driven by an RB 1070 and they do not hum. I plugged the center channel pre ouput into the 1070 and got no hum.

This amp :?: seemed to work flawlessly prior to the pre/pro switch. Is anyone out there using one of these succesfully?

[Scarp]

Do the usual thing, i.e., disconnect everything and reconnect one by one and test after making a connection. That way you can determine where the problem lays. It could be that your cables are running past by some electrical wires now?

Note: always turn off the equipment before connecting/disconnecting cables and always double check if the connection is correct.

[Andrew Pratt]

Do you have cable or satallite? If so is there a grounding block on the coax coming in from the outside? Scape's suggestions are spot on as well.

[teekster]

I have done all of this. Again, when I switch amps to my new RB1070, I don't get the noise.

BTW, I have DirecTV

Maybe I need to talk to my dealer about the amp.

[Danbry39]

I'm going to suggest a couple of more things to try because they worked for me on a fluke in the past:

1. Try plugging the amp into another outlet, hopefully not on the same line as the preamp.

2. Try to separate your power cords, etc. from each other as much as possible.

I have no idea why these have worked for me, but they have. If all else is the same as before, perhaps the cords fell out of their previous position. Again, just a stab.




Keith

[teekster]

Well, I tried one other thing. I listened to the amp with only speakers attached, no inputs. Guess what? Still hums. I'll take it to the dealer tomorrow and see if I can reproduce it.

[teekster]

Well, here is an update,

I couldn't reproduce the noise at the dealer. Thinking it might be a combination of this amp and my mileau at home, I traded it on an RMB-1095.

I brought it home and plugged it in. Guess what? A 200WPC amp makes an even louder buzz. After swearing for a while, I again tried to find the source of the buzz. I unplugged everything from the preamp and started over. When I just had the pre connected to the amp, blissful silence. Anything I connected to the preamp after this created the buzzing noise.

I grabbed an extension cord from the garage and eventually found a power outlet that eliminated the buzz (but if I jiggle the cord it comes back). The only problem is that this is located quite a distance from my built in entertainment system and I doubt my wife would let an orange extension cord run from the bar to the theater area.

I have now blown a bunch of money on this setup and have problems that I never had befor. Do you guys have any suggestions on how to clean the power to this area without breaking the bank?

[skipm]

Teekster-

You are probably going to need an electrican to come out and install a new circuit. Especially now that you have a 1095. It's probably going to cost a couple hundred dollars for a new 20 amp circuit. I'm sure there are plenty of electricans in your area that give free estimates.

-Skip

[teekster]

Well, I tried a few other things at my dealers suggestion.

Audioquest power cables: NO DIFFERENCE

High Grade Power receptacle ( I chose PS Audio): NO DIFFERENCE

Line Conditioner (Panamax 5300): This gets interesting. I plugged the AC cords in and : NO DIFFERENCE. I then noticed the cable jacks on the back. Having remembered a previous poster and my dealer asking about cable in the vicinity, I plugged it in. 90% of the noise disappeared. Having remembered a previous experiment to test this as a source of noise (I had disconnected the cable at the distribution box), I decided to repeat it. I disconnected the cable from the distribution box again. When I disconnected it from the Panamax, the noise came back.

Although this thing looks cool, I don't really want to buy it (it's on loan from my dealer). Do you guys have any cheaper methods of eliminating this type of interference?

[ht_addict]

Teekster,

Go out to your local hardware store and pick up one of those socket testers to make sure your grounding is okay throughout the house. I have the same problem with my 1095. Didn't have it when I had the RMB-1066. Only difference between the two was the power cords(1095: 3prong, 1066:2prong). I've been told the 1095 with the 3prong is picking up a poor grounding somewhere in the house. I was able to get it to the point where I had to have my ear at the speakers to hear it, by replacing my Digital Coax cable(AR Master Series) from DVD to Pre/pro with a Optical cable. Try it out.

ht_addict

[lcajiga]

teekster, I have the same problem with my 1095 but the humming goes away once music is feeded. It is apparently related to current. I will also check my Sattelite Dish connection.

Regards,
Luis




Regards,
Luis

http://www.luiscajiga.com/HT.htm

"It is not what you see and hear...it is how!"