Hiss from my Amplifier

[adamwillan]

Hi

I have got a Rotel RA-12 amp and Q acoustics 2050i floorstanders and I am concerned about a hiss coming from the speakers. From what I believe it is normal for an amplifier to produce some noise, but I can hear a hiss from a couple of metres away when there is no sound input and the amp is turned on. Is this too much?

The right channel speaker produces a much louder hiss than the left (tried switching the speakers and the loud hiss transfers to the other speaker).

Is there anything I should do to test for interference, do I need to talk to rotel or is it just something I should just accept?

Thanks in advance

Adam

 

[Big Chris]

What source are you using?

Try connecting your source to a different input of the amp. If you have another source, try that too.

 

[Mooly]

Hiss (white noise) should be minimal and pretty much inaudible from any amp at more than a foot or so from the speakers.

Whatever hiss an amp produces should also be equal on each channel so something is amiss.

Turn the volume on minimum and start with JUST the amp and speakers and NO other components connected. Does it hiss now ?

 

[miloshs]

Hello there,

Since I seem to be experiencing the same problem as OP here I decided to join into hte conversation. I have a HK3490 and Wharfedale 9.5 setup (with AKG K550 headphones) connected via toslink cable with my PC system which plays all of my music. The hissing noise I can hear when no music is playing is actually starting to be quite annoying, and it seems to me that the noise increased compared to, lets say a month ago. What is characteristic is that the noise is the same in volume wether the amp is at 0dB or -80dB.

What I did is disconnect all the connections from my amp and only tried the amp+speaker combination and the noise was still there and was same in volume, and I also tried different power outlets in my apartment to no avail.

Also the hissing im getting from the headphone out is really apparent and higher in volume compared to when played through speakers, actually the hissing coming from the headphone out is so annoying that I don't use my headphones with the amp but instead use them directly on my PC...

I'm going out tommorow to buy me some new, better speaker cables and see if it helps, but I'm 90% sure its the amplifier thats causing all the trouble.

To the OP, someone linked this in a previous thread here on What Hi-Fi so you could look at it it might shed some light on the problem... also can't wait to see if you can solve the problem. I would also suggest that you start with the steps provided by the previous poster and slowly see where it goes...

Best Regards, Milos

 

[homeworker]

I just been reading here about the hissing amps and causes

http://www.ecoustics.com/electronics/forum/home-audio/697524.html

 

[Anonymous]

Hi,

We bought to my musician son Rotel RA-12 amp. At once he heard hiss from another speaker, which I propably had not noticed. We switched the cables and were confirmed, that the hiss came from the same one amp channel. We took the amp to the seller, who also confirmed the hiss. We got a new amp, which was quiet.

But now, after about three months use, the same problem came back again also for this new unit, hiss from one channel only. The hiss is there whether the volume is down or up. Can anyone explain the problem (Rotel?), could it be an unstable, defective component on the sound chain? I hope, that the manufacturer could comment this problem as it seems to be a common problem for Rotel RA-12, which otherwise is a very good sounding amplifier.

Looking forward to some help,

Tim

 

[miloshs]

I'll be sending my HK3490 back on warranty for checkup, we will see how it goes. Hopefully something is broken so I can get a new unit

Not really satisfied with it regardless of its versatility and power

 

[Schubertplant5]

Today I did got mine :cheer:

But the reason i've got on this page doesn't mean any good. Anyhow the same problem as the topic starter. But there is one big BUT, i did found the solution for the hizz in the RA-12 amplifier.

I noticed when i turned the display light lower the hizz was getting harder, so what did i do...yes turned the display light to the max and at this point no big fat ass hizz anymore.

I hope that this is the solution for most of you guys with this same amplifier and problem.

I am pretty new in this business and this is my fist post. I hope to learn a lot from you guys and get the ultimate Hifi set-up.

cheers! Daniel (NL)

 

[TrevC]

I noticed when i turned the display light lower the hizz was getting harder, so what did i do...yes turned the display light to the max and at this point no big fat ass hizz anymore.

Sounds like a design fault.

 

[Schubertplant5]

I noticed when i turned the display light lower the hizz was getting harder, so what did i do...yes turned the display light to the max and at this point no big fat ass hizz anymore.

Sounds like a design fault.

Yes it is the relais of the screen you can hear out of your speakers...

 

[chats]

Hi, This is a fairly old post, but for those who are newly experiencing this hiss, I have it on my newly purchased RA-12 too. Its quite annoying when playing music with headphones. With my bookshelves, up close you can hear the hiss, but a foot away its gone. So I guess its not that bad in my case (atleast for now). I saw an earlier post claiming it got worse with time, I will keep watch and post an update if it does.

Minus the hiss problem with headphones, this is an awesome amp! so much umphf and punch.

Cheers,

C