noise in analog channels of an SR6200 (1 Viewer)

[Ferran Mazzanti]

Hello everybody,

first of all, let me introduce myself to this forum, since this is my first post. First post yes, but not first read since I've been following many of the threads you guys have been discussing around. Lot's of info for the neophite like me, who'e starting in this fascinating (and manifestly expensive) world.

Well, let me expose my query.I've recently purchased one Marantz SR6200 which, to my ears, works pretty well for Ht as well as music. SOund is nice and warm and I like it very much. However, I've noticed that maxing the volume I can clearly hear noise and hiss from my speakers in stereo mode. I know this has been largely discussed in many threads here, mostly devoted to the SR7200, but one think that I can't figure out is up to what point noise and hiss is normal, and starting from what level is unacceptable. So let me expose what I find by hearing to the CD analog channel without playing any CD:

0 db's: you can't hardly hear the hiss. Only sticking the ear to the mains I hear a soft noise.

+5 db's: I must put my ear to the speaker to hear a hiss, but once I do that I hear it without doubt.

+10db's: hiss is clearly there. I can even hear it (though very low) from my sitting position, 10 feet away from the mains.

+15 db's: I clearly hear the hiss at the speaker and at my sitting position.

Notice that +15 db's is the max volume this unit can reach, so I understand 8at some point) that hearing noise at that level is more or less normal.

Furthermore, all this happens only at the analog channels. Digital ones are hiss and noise free.

Another interesting thing is that the level of hissing depends on the source selected: low for CD and DVD, more apparent for TV and VCR... is that normal also?

And the last thing which I do believe is not normal, is the fact that appart from the hiss, I hear sort of an intereference signal when I connect a COAX cable from my DVD to the receiver. If I disconnect the coax from the DVD but keep it connected to the receiver, the noise is still there. I must explicitely disconnect it from the receiver to stop the noise... but the nice thing is that the noise can be heard only in analog mode (while the coax is digital). So what's going on? I presumme this sort of intereference shouldn't be there, isn't it?

Well, i guess that's enough for a first post. Help about all this will be certainly appreciated.

Cheers,

Ferran.

 

[John Garcia]

Welcome and Nice choice of receiver , I also have a 6200 and am very happy with it.
Last question first: the noise related to the cable TV is very well known, and is not the fault of the receiver, but has to do with the grounding of the cable itself. There was a fairly good post regarding how to deal with this earlier this week. You didn't say coax digital or CATV coax. If it is coax digital, there is something wrong there.
The background noise via analog is not something wrong with the receiver, but as you have already noted, it is how much noise the source itself introduces into the signal. The amp amplifies the bad stuff as well as the good stuff coming through the cables. As for digital, they tend to be quieter because the signal is less susceptible to noise.
The second thing would be the incoming power line to the receiver picking up AC noise. I purchased an AC line conditioner, and my noise floor dropped considerably. With no signal, I get no background noise at any volume level. My noisiest component, and only analog input, my CD player, is still very quiet during soft passages and between tracks.
My only other comment would be that you are listening at 0 and above. I have had my receiver at this level perhaps only once, and it is nearly unbearable. I get no distortion all the way to +15, but at excruciating SPL. I have calibrated my REF level at -8, which is already loud, and do my normal listening between -20 and -10.

 

[Ferran Mazzanti]

HI John,
thanks for the welcome and yes, I knew I purchased the right receiver
It is COAX digital what gives me headache, though one thing (important I would say) I forgot to say is that thins interference noise can only be heard at 0db's and above, going to a noticeable noise at +15db's.
An concerning analog noise at the different inputs, I can only say that VCR is producing the highest hiss I can hear while there is no cable connected to the analog VCR input.
Last but npt leats, I agree that 0db's and above is way too high to be normal listening level (I have a wife living with me, you undertand what I say ) but I just did the tests at those levels 'cause I was precisely looking for noises!
Oh well I guess the COAX interference whouldn't be there and that's enough to complain at the shop...

 

[John Garcia]

That's interesting, more noise on a specific input with nothing connected to it. I hadn't noticed that, but then I also never used the VCR input.

For the digital coax, does it do it on all of the coax inputs? Have you tried another dig coax cable? Does your DVD have an optical out that you can compare with to see if the noise goes away?

I will try mine out with different inputs, with and without the receiver plugged into the line conditioner tonight.

 

[John Garcia]

Very little noise on my analog ins, and basically zero on digital inputs, even at full volume with the conditioner, only a marginal increase without it.

 

[Ferran Mazzanti]

Aloha again,

you say you have very little noise on analog inputs... but do you find the same level of noise in all of them? I mean, at +10db's for exemple, going through analog DVD, analog CD, VCR amd Tape does produce the same amount of noise or hiss?

In my case CD has the lowest, DVd a little bit more, and TAPE and VCR the most (which is not that bad anyway, but it's there).

Concerning the digital COAX and the noise it introduces in the analog CD channel, right now I'm confused. Yesterday night I tried it back and, although noise was there, it had an appreciable lower level than the other days. Did I change anaything? NO. I start to not understand anything...

However I start to feel the following, concerning these receivers (call me sick if you want): I formerly had an SR6200 with a VERY low S/N, something like MZ00013100...

I read on the forums all the troubles that (some) of these units suffer, and was afraid I could find the same troubles with my unit. Then I asked about that in the shop and they told me to bring them back the unit for extensive test. They gave me a replacing one (the one I have now) and said that they would replace it back once they finish (starnge, isn't it?). However, since I had no troubles with my uni, I never went back to pick up my old unit.

Now I see I have this noise on analog, and am wondering if what I hear is normal. Despite the troubles people describe in forums, I seem to understand that very old units (as the one I actually had) tend to produce less hissing/noise, and even lack the S_VHS switching problem (this one I could never test since I do not have the appropriate cables).

So maybe it would be a good idea to go back to the shop and exchange my new unit (with S/N:MZ020....) for the old one.

What would be your adive regarding this?

Thanks again,

Ferran.

 

[Ferran Mazzanti]

BTW, I've phoned to the shop and they told me that since I didn't say anything about my old unit, they've sold it.
It was S/N:MZ000134001398
But they also said that if I want to exchange it again, they have one with S/N:MZ000131001199
that is, even older than the previous one. Would that be a good trade?
Another thing I noticed is that the box of my new unit had a blue strip sticked to it, which I'm afraid means that at some point it went to service repair... I'm not sure about that but seem to rememeber having read something similar in one of these forums. Or I'm going nuts? I start to believe that I'm sick, and that I should stop worrying about all those things and start enjoying the unit instead :frowning:

 

[JackS]

Frank- Take your unit back and explain to them your problem. Tell them you want to compare yours to the one they are willing to exchange for, and of course, take the one home that turned out to be best.

 

[ChrisAG]

John,

What sort of power conditioner do you use, and how much $ was it? Did you notice an improvement of overall musicality, or just the elimination of background noise?

Thanks

Chris

 

[John Garcia]

Chris - I am using a Panamax 4300 (I'll get you a link later, they carry all Panamax and Monster units for pretty good prices). I was not looking for an improvement in sound, I wanted to protect that couple of grand I spent on my gear with more than a $10 surge suppressor . Even though I was not looking for an improvement in sound, I feel there was one, though I cannot quantify it, or really measure it exactly. To me, bass sounds tighter and a little more potent, and overall sound just seems a bit more clear. This could just be the placebo effect though. I wasn't dissatisfied with the sound before the Panamax.
Ferran - The amount of noise on my unit did not change at all, at any volume between 0 and max, for any of the analog inputs. I hear NO hiss at 0 on analog, and it doesn't start until about +6 or +7. No hiss at all on digital inputs.
I will have to take a look at my S/N, but it should be fairly low, as I picked up my unit within a day or two of them hitting the stores. Personally, I would say have them exchange it one more time, and I agree that it would be best to have them take it out and test it for you. The units on the shelves now a have some updates, at least that's what I was told by a friend of mine who is a manager at Cambridge Soundworks, where I purchased mine. There were some quality control issues on some batches of units (s-vid switching, "popping" through speakers), and that has been corrected.
Link, was posted in the "places to shop" post: Link Removed

 

[Ferran Mazzanti]

Hi again,
I start to feel that right now I'm in a mess...
I can decrease the amount of hiss and almost completely remove the noise by simple disconneting cables from my other equipment. Maybe I have a problem with wires rather than with the receiver itself? Or something like ground loops? Since I don't know how to check that exactly, I'm not sure I must exchange the unit... Any hints?
However the idea of the power conditioner looks niec to me. How much is it, more or less? Will my almost-beaten-to-death wallet be able to afford it? And even worse... will me wife ever let me buy one ?
BTW, another completely different story: does anybody of you know if there's an easy way to set up the speaker levels without an SPL? Just by hearing at the test tones is not tremendously precise, isn't it?
Danke again...
PD: my name is FERRAN rather than Frank Ferran is a catalan name corresponding to Fernando, different from Frank which corresponds to Francisco...

 

[John Garcia]

Sounds like a ground loop issue to me. These threads might help:
http://www.hometheaterforum.com/htfo...ht=ground+loop
http://www.hometheaterforum.com/htfo...ht=ground+loop
If not, all I did was search for ground+loop.
Good luck!

 

[Chris PC]

I have noticed the analog noise on my SR6200 at the volumes you mention but I never hear it when listening to music. So far my only tweaks using this unit are to try and live without SOURCE DIRECT because I like to turn up the bass. The SR6200 is kind of a weird one but it sounds good for the most part. I am waiting for the new NAD's

 

[Ferran Mazzanti]

Chris PC,

I never hear anything at that volume level neither, otherwise my neighbours would bring the police home! But just for the record, I wanted to check what I find compared to other peoples units...

And i can tell you that form me music is nothing but Sound DIrect! Anything different is not reproducing it the way it was recorded, and I dislike the only idea.

Oh well, I guess there must be people for every flavour.

Thanks anyway fo the info.