Why do some receivers output "hissing" even when the volume is turned down?

[Widowmaker]

I have a six-year old Sony STR-DE835 which has served me well except for one thing. When I turn the volume down or when I select a source that is not being fed anything, i.e. selecting DVD while the DVD player is not on, there is an audible hissing sound, like the sound audiotapes used to make without Dolby NR.

So thinking that it was just my receiver, I went shopping last weekend and was surprised at what I found. I looked at the Harman Kardon AVR630, the Yamaha HTR5760, and a few others that I can't remember (they were all mid- to high level receivers) and in ALL of them, the same hissing occurred, even when the volume was turned down or muted or when a non-active source was selected.

Why is this? I was thinking that because I have a crappy Sony, this was an isolated problem but apparently not? What causing this hissing, even in expensive receivers?

[uncooked]

i dont have a hiss on any of my amps..... i own the lower 5650 yamaha model and it doesnt hiss.

from what i know hiss is usually from dirty contacts inside and if you get a compressor and blow it all out it should be good. but if you say the new ones do it to i have no idea.

are you talking a hiss from the speakers, how loud is it?

[Widowmaker]

i dont have a hiss on any of my amps..... i own the lower 5650 yamaha model and it doesnt hiss.

from what i know hiss is usually from dirty contacts inside and if you get a compressor and blow it all out it should be good. but if you say the new ones do it to i have no idea.

are you talking a hiss from the speakers, how loud is it?

Yes, I'm talking about hissing coming from the speakers, the receivers themselves are quiet. The hiss really isn't that loud, but it's audible if you're sitting right beside the speaker. It's most noticeable when playing something at low volume, over the sound effects, music, etc., the hiss can still be detected.

[uncooked]

i just checked my amps and non of them have that at all. If i turn it on to a blank input and turn the volume to half way + and stick my ear right up almost touching the tweeter i can hear a tiny really really quiet sound. but nothing like your talking about. if i move 3 inches away from the speaker i cant here anything. and as for the hiss will music is playing at low volumes i dont have that either. how loud would you say it is?

[Widowmaker]

It's actually not that loud, maybe a little bit above a whisper level, but again, it's detectable when I'm playing something with the volume low. At high volume, the hiss is drowned out.

[Woochifer]

It may be something in the analog preamp section. To confirm this, play a DVD (assuming that you use a digital connection from the DVD player) and hit the pause button. If the hissing occurs here too, then the problem is in the amp in all likelihood. On my receiver, the digital sources are completely silent, while I can detect a slight bit of noise (with the volume turned way up to max) with the analog sources.

[Widowmaker]

It may be something in the analog preamp section. To confirm this, play a DVD (assuming that you use a digital connection from the DVD player) and hit the pause button. If the hissing occurs here too, then the problem is in the amp in all likelihood. On my receiver, the digital sources are completely silent, while I can detect a slight bit of noise (with the volume turned way up to max) with the analog sources.

Yeah, it happens whether I play a digital source or analog source. Unfortunately, it looks like I'll have to shop around carefully to find a receiver that doesn't do this.

Thanks for the replies, everyone.

[uncooked]

could it possibly be cause by dirty power, or some kind of interference. is it plugged into a power bar?

[Widowmaker]

It's plugged into a surge protector but I've tried plugging it directly into the wall and even using a different surge protector and it's all the same. Oh well, looks like I will be in the market for a new receiver.

[ray5aes]

Sony DE models have been known to have a hiss sound when the receiver is on coming from the speakers.
If you really want to get rid of it you may have to have it serviced.

[markw]

This is due to, I believe, a characteristic called "thermal (thermionic?) emission", whereby heat generated is some parts causes the electrons to vibrate and this, in turn, generates this noise.

It's just more noticable in some cases than others. Generally, the better the equipment, the less the noise.

This hissing noise can be exaggerated by having speakers that tend to emphasize the high end and by sitting close to the speaker. Putting one's ear up to the speaker to hear it is a sure way to contract an expensive case of audio nervosa.

If you can't hear it from your normal listening position, I wouldn't worry too much about it.

[Wireworm5]

If you have a TT then this could be the culprit. I have a turntable that has a bad connection at the cartridge & tonearm, but this sounds more like a hum. Another possibilty I've read is a ground problem, that is easily solved by attaching a two pronged adaptor to the 3 prong power cord of your receiver. It's a cheap fix so give it a try and let us know.
My .02 cents

[kfalls]

I have Onkyo, Yamaha, and Denon receivers and I don't hear any hiss at all until after the volume is past half way. I tried headphones as well to see if I could hear noise from the preamp and the same held true. Sony's are notorious for marginal power supplies, but usually if it's a power supply, or a grounding problem you get 60Hz hum, well below the frequency I would consider to be "hiss". Most subs I've had/listened to have noticable hum.

[ray5aes]

Widowmaker,
Here is an old review on the DE-545 model that had issues with the hiss.

Summary:
I would like to inform all those guys who own this receiver and have the same problem that I had, the Hiss!!! Well, the solution is simple...Get it back to the Sony Service and they will fix it!!! I took mine back and in 2 weeks it was fixed. No more Hiss and it sounds great!!! They admit that some models with a specific serial number had this problem with the hiss and not all of them. So, they replaced a box inside the Amplifier and that was all...A new machine that sounds better that ever...And if you replace your cables with monster cables and connect your CD, DVD with optical fibres the hole result would be more than perfect...amazing...To conclude, this receiver with no hiss at all is a great choice for the money...

Anyway try some of the options the poster's on this site have suggested and you may get rid of it or learn to live with it.

Good luck

[Widowmaker]

Thanks for the replies everyone. I was hankering for a new receiver anyway and the hissing is a convenient excuse to get a new one (thank goodness I'm not married, LOL).

[Quagmire]

This is due to, I believe, a characteristic called "thermal (thermionic?) emission", whereby heat generated is some parts causes the electrons to vibrate and this, in turn, generates this noise.

It's just more noticable in some cases than others. Generally, the better the equipment, the less the noise.

This hissing noise can be exaggerated by having speakers that tend to emphasize the high end and by sitting close to the speaker. Putting one's ear up to the speaker to hear it is a sure way to contract an expensive case of audio nervosa.

If you can't hear it from your normal listening position, I wouldn't worry too much about it.

I've heard that "hiss" can be attributed to a receiver/amp which has poor damping. This would seem to coincide with your explanation of the cause.

Q

[cam]

Thanks for the replies everyone. I was hankering for a new receiver anyway and the hissing is a convenient excuse to get a new one (thank goodness I'm not married, LOL).

just make sure she is open to an upgrade here or there. She gets hardwood throughout, you get more power. Fair is fair.