Amp Buzz - Parasound HCA 806

Pycroft

Hello...Sorry if you kept track of my previous post. It started as a question about pricing, and now that I've bought the amp, I'm having troubles. Figured I'd start a new thread for some help.

The Parasound HCA 806 - 6 channel amp I bought used has a buzz, and the output of the amp isn't what I think it should be. I heard this amp power the seller's speakers and it seemed fine. The buzz is constant...when I have nothing playing through the AVR (Music or Blu-Ray) the buzz is there. If I turn the volume up or down, it remains the same loudness. When I first heard the buzz I had the amp plugged into a surge protector. When I plugged it directly into the wall, the buzz was less, but still there. Behind the amp, each speaker has a knob, I'm assuming to control volume of the individual speaker. When I turn the knob up, the buzzing is louder, when I turn down, it goes away, but of course, no sound. Even with the buzz, I played some music through the IPod dock, and a movie. The center channel trumps the sound of the RTA's by a mile (Or maybe a mile and a half). Someone suggested it may be an electrical problem. FYI, there are no flourescent lights (suggested by someone) so that shouldn't be a problem. Also, I am using the same RCA plugs (2 prong to 2 prong) that I used with my other amp, and that amp had no buzz, so I'm assuming that's not it. I have only, so far, plugged the speakers into channels 1 and 2. I have tried it in bridging mode, and regular, although you are only able to bridge channels 3 and 4, and 5 and 6, so I figured that wouldn't affect anything.

Can someone suggest things I can try before assuming it's a power problem? To be honest, I've been here a while, but am still stupid when it comes to anything. Don't assume ANYTHING is too stupid for me to do

I appreciate the help you may be able to give. I need options

James

pearsall001

Sounds like a ground loop issue. Throw a cheater plug (3 prong to two prong adapter) on the amp & see it that takes care of it. If it does, that's just a temporary fix until you can track down the problem. These things can be a real **** to track down. I'm sure others will chime in on how to troubleshoot the problem for you. I'm not all that technical.

Pycroft

I have no idea what a cheater plug is, but someone else mentioned ground loop. Does that affect just the one plug in the outlet? The amp is now plugged into the bottome of 2 outlets. If I plug it into the top, would that possibly fix it? I'm planning on compiling a list of whatever you guys suggest to try, and see what works. I'm just hoping it's not a problem with the actual amp. Thanks, and keep em coming!

James

vc69

Pycroft wrote: »

I have no idea what a cheater plug is, but someone else mentioned ground loop. Does that affect just the one plug in the outlet? The amp is now plugged into the bottome of 2 outlets. If I plug it into the top, would that possibly fix it? I'm planning on compiling a list of whatever you guys suggest to try, and see what works. I'm just hoping it's not a problem with the actual amp. Thanks, and keep em coming!

James

James,
It's one of those adapters that lets you plug a 3 prong AC plug into a 2 prong outlet. We call them "ground lifts" where I come from.

I don't know if it will help, but it is worth a try. Also, you may want to swap IC's and check with someone to be sure you have the amp configured correctly (bridged modes, etc).

Good luck!

Pycroft

Would I buy an adapter at a hardware store? An electronics store? I'll plan on looking for one on the way home today. I also play on taking a picture ofthe back of the amp and posting it this evening. Thanks, and keep em coming

vc69

Hardware store, Wally world, maybe even a supermarket in the hardware section. They are common.

George Grand

I think I have a couple James. It sounds very much like the problem. Hardly worth the drive up here though, as they are very common items as stated above. Usually grey colored, it is nothing more than a new end for your amp's power cord. It has a receptacle to accept the existing three-prong cord coming off the end of your amp, and has a two-prong male to go into the wall. They are about a buck.

Pycroft

Great everyone, thanks. I will stop and pick one up. Someone said it is a typical problem, but a temporary solution. How does one fix a ground loop? I don't know what it is...Is that something I hvae to worry about or can I use the temporary fix until the end of time without worry?

I'll check it out tonight, and report back.

James

TG Meat

Let us know how it works out for you.

ivansfo

This is what a cheater plug looks like.



Another common cause of ground loop involve the cable tv or satellite feed. You temporarily disconnect the cable to see if that could be it too.

dbaldus

I have another suggestion if the cheater plug doesn't work:

Try making sure that none of the power cables are crossing/touching your interconnects. Try to keep your cables as neat as possible - to do this, it may help to take your components off of the audio rack and set them out next to each other.

I had the same problem as you are describing when I got my HCA-2200II so I tried the cheater plug but it did not work. After wiggling some wires around behind my audio rack, the sound would go away sometimes. I eventually figured out that whenever my interconnects were leaning up against my power cords, the buzzing would occur.

Good luck.

Pycroft

Well, the cheater plug WORKED! It sounds just perfect now! Only question is, is it safe, or do I have to do something other than the cheater plug? Thanks all for the help and suggestions!

James

vc69

You should be good.

I wonder what may be on that circuit that may be causing the buzz. Are all of your components plugged into the same circuit?

I'm just glad it worked for you.

Pycroft

Not everything is plugged in there...but I don' tknow much about electronics. Just glad it works. I thought i twas the amp, and it was a bad purchase. So 6x80wpc Parasound amp for 200 bucks...not bad!

Pycroft

Also...is this ground issue something that would be fixed by a power conditioner? I was thinking I should get one, basically because I have everythign plugged into just 6 channel surge protectors.

pearsall001

Pycroft wrote: »

Also...is this ground issue something that would be fixed by a power conditioner? I was thinking I should get one, basically because I have everythign plugged into just 6 channel surge protectors.

No!!! A ground loop is an evil devil that must be sought out & eliminated. A power conditioner won't help at all in that area. Get one for the surge protection, but it'll do nothing as far as correcting the ground loop.

CoolJazz

A ground loop is caused in a system where two different ground references exist and the components share the ground by the nature of the audio wiring. In clear english, unbalanced connections between the devices.

Common sources of the grounds include the 3rd prong of the power cord and the coax coming in from cable. Also, crossing between different power sources where the neutral is floating unequally and those voltage differences can also get troublesome.

The ground loop buzz is actually caused by current flowing between devices. This can be cured by using first a common power source. Eliminating the alternate source of the coax ground by using an isolation transformer. The "cheater" lifts the ground from that source and is useful as a troubleshooting tool, but is really unsafe and should be removed as soon as you can find where the alternate source of ground is coming from!

One additional source of noise, that is a bit different, can be from the power transformer being a bit unequal in it's windings. That can be checked on the two prong power cords by flipping it around and seeing if a buzz level goes down.

Hope some of this helps to explain and not confuse....

CoolJazz