Hi. I have a JVC RX-778V Dolby Digital Receiver. Hook up to it i have a 2-Channel QSC Professional Amp( 4 ohms). My surrounds are Klipsch Speakers(8 ohms) . When i have my receiver on DVD i get great surrounds, but i notice on the back right surround there is a loud hum, almost a buzz sound. Yes both have a hiss sound cause of the amp, but still i get a louder sounding hum on the right surround. What an i do to fix that?
When i play my LD, the buzzing then comes from both surrounds. The amp is hooked up to the receiver though the out speakers L & R up to the in L & R channels on the back of the amp where you screw it on.

You using an external amp to power your surrounds? If so why?

If the amp is connected to the L&R main preouts on the JVC you are getting the wrong sound info(main channel sound, not the surround channel sound) out of your surround speakers. You are not getting DD if it is hooked this way.

This has nothing to do with the buzzing, but I thought I would mention it.

For the buzz:

Make sure all connectors are tight.

See if your RCA passes over/under a power cable which could cause interference if the cable isn't sheilded properly.

Jumbo is correct. I was getting a terrible buzz from my sub because the wiring was laying next to a power cord for some lights. I used shielded cable, and that went away.

Jumbo, my amp is connected to the left and right surround speaker out on the receiver. The amp really gives the surrounds that theater quality sound, awesome. So you say it's the power cord, or the right surround speaker, or should i get a new power surge protector? I'm going shopping today, where can i get a good one? Thanks for your help your guys.

Before investing in a new surge protector just make sure all the connections between the receiver and amp are tight.

Also check to see if the RCA's running from the receiver to the amp aren't resting on any power cables.

I was just surprised to see you using a seperate amp to power the surrounds. Most people use a seperate amp for the mains

BTW, How do you like that amp? What is the wattage? I have 2 passive subs running off an amp rated 120x2 at 4ohms and would like to get a higher power amp, possibly 200/250x2 into 4 ohms.

Considering it is just the subs I don't need really expensive one(with airy highs) just some decent clean, high current power. I was looking as some of the amps at Parts Express, I think QSC is one of the brands they have.

Good luck! Hopefully it is just a cable shielding problem

Jumbo, i am not using RCA cords, i am using speaker wire from the speaker out from the surrounds, to the 2 channel ins on the receiver, you have to screw the wire tight on the amp. Amp is 400 watts per channel @ 4 ohms.

I realize I'm just jumping in at the end here, but based on what you said in the post I quoted, I have no idea how you're using a receiver and external amplifier.

Is this the path?
receiver surround pre-outs --> amplifier input --> speakers

If it's not, please explain how you have it hooked up, and what kind of connection (speaker wire vs. rca) you're using at each step.

Receiver surround L&R speaker out-->Channel in L&R on back of amp --> Out to surround speakers.

When i hook up my LD to the receiver through the CD in or the Aux in, i get the buzz on both surrounds. Weird. Sometimes it takes a minute or 2, then the buzz starts. Most noticible during quiet movie scenes.

I say take the amp out of the equation. It might be the amp that is causing the hum. Hook your rear directly to the receiver and see if it goes away

i may be way out of order on this, but, it sounds like you are driving the amplified signal from your rear surrond outputs, on the jvc, into what possibly may be the preamp level input of the second amplifier that you are using. if this is the case you would probably get all kinds of noises, because the jvc's amplified output would be incompatible with the input of the second amplifier, if that input is a preamp level input, and there is no type of provision for making it compatible with an amplified signal, such as some type of internal circuitry or external device in between the jvc and second amplifier. this type of mix/match, without some type of conversion, could also damage the jvc's output stage as well as the input stage of the second amplifier. of course, i may be way of base and totaly wrong.........

OK I am officially lost!?

This is how I would set it up:

1. Surround L&R RCA pre-out on the JVC to the RCA inputs on the back of the amp.

2. Speaker wire connected from L&R channels of the amp to the L&R surround speakers.

400x2 watts into 4 ohms would translate to be around 200-250x2 watts into 8 ohms(nominal impedence of your speakers) depending on the amp. You are going to have some seriously loud surrounds or they are going to blow up!

I have no RCA Pre-out on the back of my Receiver. All i have are connectors where you snap and lock the two ends of the speaker wire ( black, and red).
The QSC is an movie theatre amp. it has a funny looking plug input left and right input that has a tab above a circular shaped plug about 2 1/2 size larger than an RCA plug, and in the center has another little hole that is shaped like a plus-sign.
I dont have it connected there, i have it connected at channel 1 input and channel 2 input. Where it says channel one there are 2 screws. you loosen the screw and put the ends (black & red) of one of the speaker wires. Same thing to the channel 2 . Then tighten the screws.
Like i said , my receiver has not pre outs, only speaker connections( wire type) for L,R,Center,Surr. L, Surr. R, and sub.

These connections are probably for a line-level signal, not the amplified signal already coming out of your receiver's speaker outs. You should just hook up the rear speakers to the receiver. If you really want to amplify the rear channels separately, you'll have to use line-level outputs for them. The amp also doesn't seem to be intended for your uses, so you should be cautious.

And I will repeat the question on everyone's mind: Why are you amplifying the rear channels in the first place? Wouldn't it be more beneficial to amplify the mains, since there is so much more info on those channels? Are you sure you know what you're doing?

By using the receiver's speaker outputs, you are sending an amplified signal to another amplifier, and I could be wrong, but I would gather that would be more then sufficient to introduce some buzzing sounds into the equation. My advice is what many others here have said: lose the second amp, and let your receiver do the work for the surrounds.

The amp improves the surrounds, much more umph than what the receiver feeds them.

Well since you don't want to take anyone advice here then you will have to live with the humming.
I would be cautious because over time you will ruin one or both pieces of your equipment!!
The second amp is really not needed! What kind of speakers are you using for the rears anyway??
Who ever sold it to you should be shot! Because they would of told you it was not needed either. For the price you paid for both pieces of equipment you could of bought 1 receiver that had the umph!

Yep. Same thing happened to me a while back.

Then by all means, enjoy that umph, and the hum that your getting with it, because it's not going to go away. I guess you also prefer to have more 'umph' in your surrounds then your mains as well.

Thanks