Separates, any hiss?

outlander · March 2005

I was reading a post from a Rotel forum and someone posted about hearing a hiss from the speakers when they turned on their separate amp. I had never noticed it before but I figured Id check mine a little more closely. Sure enough if I get real close to the speaker with the amp and preamp on I can hear a slight hiss. This is with no source signal and independent of the volume level. This is same with both my Rotel and Adcom amps. I know it really doesnt matter, because if music was coming through the speakers I wouldnt hear the hiss, but Im curious if other peoples setups are doing the same thing?
O

jrlouie · March 2005

Yep, I hear an ever so slight hiss coming from my Lsi's, for those that are hooked up to a power amp. Mine is similar, I can't hear it unless I put my ear next to the speaker.

jcaut · March 2005

IMO and from experience, I would say that is normal. Some are a little quieter than others, but if you put your ear right up against a tweeter with the power on, I think you're going to hear some hiss. I've got Carver amps (three different ones) and they all make a very slight hiss. The quietest is a TFM-35 and I can just BARELY hear a hiss if I put my ear near the tweeters. The loudest (and it's still very quiet) is the TFM 4.0 (which is same as M4.0t, 375wpc) and I'd characterize it as making more of a hum. Higher end gear might be quieter, but I wouldn't expect complete silence.

Jason

Ethancf · March 2005

Yup, I get it too.

Pauly · March 2005

M 1.0 T Carver does it as well.

Pauly

faster100 · March 2005

Unfortunatly with my grunt ball gear, I have a hissssss

a buzz sometimes, But never a HUMMM

jmierzur · March 2005

- Rotel amp has a faint hiss.
- Simaudio amp is dead quiet.
- Rotel pre-amp is quite noisy.

Guess which will be replaced next.

heiney9 · March 2005

Yup, mine too. I have to get really close to the Polks to hear it, but it's there. I've often wondered myself if this was normal, but it's never bothered me because it's inaudible unless your right on top of the speakers.

I have other noise issues as well. Sometimes when idiling I can hear a local AM radio station faintly through my speakers, and I don't even have a tuner in my system. I do live about 3 miles from the transmitting tower however.

I also have some RF type buzzing which I can faintly hear. Not to hijack this thread but what do people think of AC line conditioners? I've heard some good and some bad about line conditioners. I know I have crappy AC. Would a line conditioner help the hiss problem? I'm sure there are some trade off's using a line conditioner.

Heiney9

steveinaz · March 2005

You'll get hiss out of any amp. haven't met one yet that didn't hiss at the tweeter at full volume. (ear to the tweeter).

jmierzur · March 2005

Hiss at 'full volume' would be noise from the amp AND pre-amp.

outlander · March 2005

Thanks very much for the replies guys. I hate to say it but I feel better already. I would imagine the more efficient the speakers the louder the hiss. Or if you had a horn or a titanium dome it might be louder too.
Thanks again!
O

steveinaz · March 2005

I'm talking about the outputs on the amp maxed. Preamp turned off.

The "hiss" is related to your S/N Ratio specification. There's never been an amp built that has no noise floor.

F1nut · March 2005

A little hiss, heard right up next to the tweeter, is normal.

jmierzur · March 2005

Steve,

Are you referring to output level controls on an amp? If not, please elaborate on what you mean.

Alot of amps would be 'maxed' as they do not have output level controls.

Edit:

Looked at the HCA-1500A manual. Yes, your amp does have the output level controls on the back panel. Yes, this would be set to the maximum level.

steveinaz · March 2005

Yes, the output levels on the amp (if so equipped), like my Parasound. Yes, amps w/o output adjustment are maxed by default.

McLoki · March 2005

I have an onkyo 777avr that I am using as a pre for my front stage and a Cinepro 3k6 that is running my front stage and sub.

With the volume turned all the way down on the Onkyo, I get a very quiet hiss that I have to put my ear up to the tweeter to hear.

With the volume turned all the way up on the Onkyo (no source playing) the hiss get s quite a bit louder and I can hear it a few feet away from the speaker.

Looks like a pre-amp upgrade is in order

Michael

outlander · March 2005

Sorry about that Mike, your preamp was probably fine untill I said something.
O

McLoki · March 2005

Originally posted by outlander
Sorry about that Mike, your preamp was probably fine untill I said something.
O

Actually I did test this when I first got the amp and heard nothing. It has just been since I started reading this thread that I started having the issue, and now I hear it all the time..... Sometimes ignorance is bliss...:rolleyes:

Michael

steveinaz · March 2005

Save your money, it's normal. Especially if you have a source powered on.

McLoki · March 2005

Originally posted by steveinaz
Especially if you have a source powered on.

Good. I just noticed it today at luch while queing up Master and Commander. (all testing was done with source powered on but paused so there was no sound) I will do a little more testing later and see what effects it has...

Michael

2+2 · March 2005

jmeizur, try running a ground wire between the amp chassis and the pre amp chassis....try multiple spots....the chassis screws of the amp to another screw on the preamp...or even a ground screw of the preamp's phono section. You may be hearing buzzing due to ground differentials.....

jmierzur · March 2005

The entire system is directly plugged into the BPT-2.5 so should have the same potential. I will give this a try. 2+2, thanks for the suggestion.

JM

Airplay355 · May 2005

I decided to resurrect this old thread instead of starting a new one.

I have the same problem all you guys have except I wouldn't classify mine as normal. Right now my system is fairly quiet. My speakers make some slight noise, but it's not even loud enough to overpower the buzz of my carver amp. This is with only the amp and preamp plugged in, all other souces are not only off, but unplugged. If I plug in the DVD player, the noise increases. Add the PS2, it gets even louder, connect the TV and the noise is so loud that during quiet dialogue in DVD's it's audible from 10ft away. I don't think it's a ground loop because it's all in the tweeters, and I thought ground loops were 60 hz noise. If it could be a ground loop, I'm not sure if my house is grounded. My house was built in 1952, and I think my dad was the one who changed the outlets to 3 prong. I'm not sure though. I was also considering a power conditioner but I would like to exhaust all possibilities that don't involve spending money before I get one.

F1nut · May 2005

Sounds like a transformer problem. You could try a PS Audio UPC-200 with Hum buster, but if it were me I'd be looking into a new amp.

Airplay355 · May 2005

damnit I just got this amp. What makes you think it's the amp? Is there any way I could check to see if it was the amp? How does plugging other things in, cause a buzz from the amp? I'm not saying you are wrong, because I have no idea where it's from, I just wouldnt want to get a new amp, only to have the same problem. Especially because I like my Carver amp

F1nut · May 2005

What happens when you power up only the amp, can you hear a buzz then?

jcaut · May 2005

With just the amp powered up, you should have to get pretty close to the speakers to hear anything, and it should be faint. Those "Magnetic Field" amps seem to make a "transformer buzz" noise that can be heard from the transformer itself. My TFM 4.0 seems to pick it up a bit in the right channel, and it comes through the speaker just slightly. Not noticable under "normal" conditions, but it's there. I never noticed that m0.5t making noise through the speakers though. Certainly nothing that would have been noticable over any signal at all, or from any reasonable listening distance from the speakers. I used it most with some RT55i's, for the sake of comparison. It was quieter than my 4.0 and not quite as quiet as my TFM-35, IIRC.

You say your outlets were changed to three-prong at some point in the past. Do you know if the house was re-wired or if just the receptacles were changed? Bad wiring can cause some strange problems-- I would also think that a power problem or ground loop would most likely cause a 60Hz noise, but I guess anything's possible. Any light dimmers or fluorescent lights on the circuit your equipment's plugged into? No possibility of a bad interconnect anywhere in your system? You don't have wires coiled up anywhere, do you?

McLoki · May 2005

With just the amp plugged in do you get any noise? how bout the amp and the TV?

Plug the amp into a separate circut in your house and see if the noise continues. (use an long extension cord for the test)

Worth a shot for a free test....

Michael

heiney9 · May 2005

I'm confused....Is it a buzz we are talking about or hiss, as the original thread was talking about?

Hiss is very normal, no component is completely dead silent. Buzzing is a different animal and can be difficult to isolate. Sometimes electricity has a mind of its own. The TV is the probably the most offending culprit, not sure what to tell you to fix it. As others have suggested try other outlets to isolate the problem. In regards to the TV make sure you are top notch cables when the audio of the TV is being fed thru your system. For some reason if you use cheap cable to connect the TV audio it can cause noise problems. At minimum it should be a sheilded cable.

I've 2 similar situations that I just randomly was able to fix. My Adcom amp starting developing a transformer hum for a whlie. It bugged the hell out of me. I later found out if I had the humidifier plugged in to the same circuit that's when the trans. would hum. Solution; plugged humidifier into an outlet on another circuit. Also for a while I found while listening to DVD's sometimes I'd hear this faint scratchy/popping noise, like digi-noise on a cd. This was completely random of course. Later found out that when I had my halogen lamp with dimmer set to certain postions it would cause this phenomenon. Just keep looking and trying to isolate the problem.

As far a power conditioner it may or maynot help your particular situation. If you can buy one from a place with a liberal return policy that would be your best bet there.

Good luck

H9

Airplay355 · May 2005

I think my dad just changed the recptacles, so I'm guessing that nothing in my house is grounded, but I don't know for sure. I do have a 4 foot blacklight plugged into a different powerstrip and on a different outlet, but same circuit. It doesn't seem to be causing any problems at all, I have it on right now and the only buzzing I'm getting is from my DVD player because I unplugged everything else. My Buzz increases with the more sources I add, or even plug in.

My TV makes things worst, but it's not from running TV audio to my preamp, it's from running video to the TV. My DVD players audio outs go to the preamp and then I run a seperate cable from the video out to the TV, as soon as I plug that in the buzz gets much worse. I tried using a different TV and the buzz still increased but not as bad. If I plug the audio cables of my playstation into my preamp and then plug the video cable into the TV I get the same problem, lots of buzz.

I'm using CObalt cables between the DVD player and the preamp, and the preamp and the amp. They aren't coiled, they are just as long as they need to be. I don't think its the cables in my system tho, I think it has to do with the electricity. When I plug something in, or unplug something, I get a pop through my speakers. If I turn my fan on, I get a pop in my speakers. I'm pretty sure my house has bad wiring because when the furnace or a washing machine goes on the lights usually dim.

I don't think it's the amp, and the transformer hum of the Carver amp isn't a problem, that is only audible if the room is dead silent, as soon as music goes on it disappears. The buzz from the speakers is very audible, with everything hooked up.

If I turn the treble all the way up it gets worse so I'm pretty sure its mostly in my tweeters, because turning the bass up has no effect.

The nearest place with power conditioners is 30 min away and not open until Tuesday. I don't want to go to best buy to drop $200 on a conditioner to fix a buzz.

I'm callin my electrician buddy today and maybe he will be able to tell me whats wrong.

If I found out that nothing was grounded, do you think grounding it would get rid of this stupid problem?

thehaens@cox.net · June 2005

I just stumbled upon this thread and thought I would put in my .02 I have had the same humm/hiss coming from my amps. It can sometimes be attributed to a ground loop. But not always. I can't wait for the day I have a home built to my specs. Specifically a common copper ground, and a bus bar to hook all my audi/video equipment to...Until that time comes I have had really good success with a few Jensen Stereo Isolators Model CI-2RR....They take the humm and most of the hiss right out of the signal path. I am not sure how much of the signal it actually takes out, but the difference in "noise" from the speakers is night and day.

Scott

http://www.jensen-transformers.com/iso_aud.html

They also make video isolators as well...

Separates, any hiss?

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