Question about hiss from Sony STR-DA4ES

[Schwa72]

<font color='#000000'>I posted this question over on AVS Forum and the Home Theater forum but haven't had any luck with answers. I figured with all the hub-bub here lately with the 'DA4ES, someone might be able to weigh in, so here goes:

I just got my new receiver this past weekend, and I have noticed a fair amount of hiss through the speakers at high volumes with using a DSP mode (like dts:neo-6 or DPL-II) with an analog-only input or when an input is forced to analog mode. For example, if I set the receiver to the TAPE input, it's dead quiet (unless I crank it to -10 dB or higher, when I can hear just a bit of analog noise). However, if I turn DPL-II or something similar on at this high volume setting, then the hiss volume rises substantially. Of course, this is at very high volumes and isn't generally noticable in normal listening -- there hasn't been a source playing when I noticed the hiss. Plus, it's easily avoided, because I don't hear any additional noise when using DSP modes with a digital signal!

What I'm wondering is if this is normal. All of my older Sony receivers (STR-DA50ES and STR-D915) exhibit similar behavior, so I think it's just the nature of the beast. Still, my mind is on it now, and I probably will never use DPL-II or similar processing modes with analog-only sources.

FWIW, I'm running Klipsch Reference speakers all around which are very sensitive and thus revealing.

If you own a 'DA4ES, please check for this hiss before you reply and say you can't hear it...it's something you wouldn't likely notice unless specifically checking for it, as I doubt many people are frequently applying DPL-II or similar algorithms to non-digital sources.

As a bit of an update, I just got finished comparing the DSP/analog noise (using my Rat Shack SPL meter) from my old 'DA50ES to the noise from my 'DA4ES and they both are very, very comparable at max volume. I have to believe that my 'DA4ES is performing properly based on my measurements and based on another user's observations here.</font>

 

[Guest]

<font color='#000000'>Noise is normal and completely unavoidable in any electronic system.

You have very sensitive speakers and therefore will not be listening to anything at -10 dB! Chances are, you would be clipping the amp at -10 dB on the volume dial, if a signal was actually present. It's all about Signal-to-Noise ratio, that is, how much noise is there compared to the signal (music) level. If the noise is undetectable at normal (or even above normal) listening levels, then there is no reason for conern.

Note that there are a few tricks that can help to reduce noise. I have used them with my older Sony receiver with great success:
1. Use shorted RCA plugs on all unused inputs (but not the Record-outs!). You can make these very cheaply... just buy a package or two of plugs from radio shack (cheapies do fine), remove the plastic shielding, and bend the ground and centre-pin (signal) connections together and solder them. replace the plastic shielding. This shorts the inputs to ground eliminating any possibility of picking up noise.
2. Select the input manually for all of your sources. Do not use the Auto input select functionality.

when you enable DPL-II on an analog input, the receiver has to put it through the A/D converters, process it using the DPL-II algorithm (fairly complex processing), and run it back through the D/A converters. Every step adds some noise, and note that you now have 6 channels instead of just 2 to re-create that noise. Again, Signal to Noise Ratio (SNR or S/N) is what is important. Imagine how loud the &quot;singal&quot; (music) would be at -10 on the volume dial!

To put your mind at ease, sit back and find a comfortable listening level. Now stop the music and note the volume position. Now find how much higher (in dB) you have to turn it up before you hear noise. Note that 10 dB higher on the volume dial results in 10 times the output power, so 20 dB is 100 times, and so on. Now, you can rest assured that the noise is not going to be noiticable during any actual listening situation, because your ears would be in pain from the output of your Klipsch's long before the volume dial got that high.</font>

 

[Schwa72]

<font color='#000000'>Actually, when using DSP processing on an analog input with no signal coming in, the hiss just starts to become noticeable at around a -30 dB volume setting.  This volume level is loud, but not completely deafening.  Anyway, I measured the level of &quot;hiss&quot; with an SPL meter at about 1 inch from my tweeter and at max gain (0 dB volume setting) this was about 72 dB (once again, this &quot;hiss&quot; is only evident when applying a DSP mode to an analog input with no signal -- hiss when the receiver is processing a digital signal or in Analog Direct mode is unmeasureable).  Later, at -54 dB on my volume dial, I measured the output level of a song at about 1 inch from my tweeter to be about 90 dB.  So (follow my logic here), the level of hiss at that same -54 dB on the volume knob would be 72 dB - 54 dB = 18 dB.  This gives a worst-case S/N ratio of 90 dB - 18 dB = 72 dB with analog DSP processing active, which is at least as good as a good Dolby-S encoded tape.  The true S/N ratio is probably even higher because it's likely the song I was playing wasn't recorded at the maximum possible volume.

Since this is worst case, I suppose I can live with it!!  

FWIW, I did some more measurements on my old 'DA50ES and found that the level of hiss was practically the same with the older receiver when applying a DSP to an analog input.  Also, another 'DA4ES owner and a 'DA7ES owner have reported similar hissing under the conditions I've described, so I think all is well with my new toy.

Thanks for your help!</font>

 

[Guest]

<font color='#000000'>What kind of hissing sound do you refer to? like the one from the teakettle? if that's the case then it's bad.
I tried with my Sony 5ES today and when it is in analog mode or with DSP, I hear low noise with very high volume but not a hissing sound. Just like you turn TV or tuner to a non valid broadcasting channel/ freq. The noise is very flat and not that bad.
However, I don't have any kind of this noise with my Yammie and HK pre-amp PT2500. They are very clean. I don't know if Steve or Gene are aware of this noise?
One thing I am happy about the 5ES is it gives my nice bass to my sub and front. I tried so hard with my yammie but coun't get that tight bass thanks to the Bass management in the ES.
I have a hard time to tell people that I have a sony ES receiver, not a low end receiver. When they just look at it, they said &quot;you bought a sony? sony is not good. &quot;</font>

 

[steve]

<font color='#000000'>When we listened to the 5ES using it's internal amplifier, it does have a low level &quot;hiss,&quot; as do most digital Receivers and Processors. &nbsp;The amount or volume of the hiss varies from manufacturer and/or model, and it is somewhat dependant on the Electrical Components within the unit.

There is even a &quot;hiss&quot; on the 9000ES. &nbsp;It's challenging to compare the level of hiss as most models have different calibration levels for volume control; so I can't say for sure if the 5ES is better/worse than the 4ES or the 9000ES when it comes to the hiss noise.

I will ask Gene to get into more detail on this issue in the near future.

Regards,
Stevie D</font>

 

[gene]

<font color='#000000'>SCHWa72;

The problem you are experiencing is not uncommon. &nbsp;Almost all Receivers/Processors have higher noise output when engaged in a DSP mode. &nbsp;This is especially noticeable with high efficient speakers such as your Klipsh. &nbsp;If the hissing isn't audible from more than a few feet away, I wouldn't worry about it. &nbsp;If you are maxing the volume and hearing the hissing, that is irrelivant as if you value your hearing, you wont be listening to movies/music that loudly anyways. &nbsp;As long as you can't hear the hissing while listening to music/movies, it should not be an issue. &nbsp;You may wish to place your rear speakers further away from your listening postion, if the hissing becomes too problematic.</font>

 

[Schwa72]

<font color='#000000'>Thanks for the replies, guys. &nbsp;The hissing is only significant when DSP processing is applied to an analog input, so in the vast majority of cases I avoid it completely, anyway. &nbsp;I've posted the same question on a couple of other boards (Home Theater Forum, Agoraquest) and other 'DA4ES/'DA7ES owners have reported similar hiss. &nbsp;I also checked out a 'DA2ES at a local dealer today and it does the same thing, also.</font>

 

[Guest]

<font color='#000000'>Hello,

My DA4ES exhibits the same hiss at really high volume levels with DSP on in most anymode...

I listen at -30bd when I get into the listening mode, most often closer to -40 bd to -35 bd down...no problems with any hiss...

What your hearing is nothig to worrry about..

Alex</font>

 

[F-16 419]

Today I swapped out my Sony DA50ES that I purchased about 14 years ago! It always produced a slight hiss, more noticable at higher volumes. If I cranked up the volume with the music or movie on pause, I could easily hear a hiss out of the speakers. Over the years, I thought it might be bad cables or bad ground and so on. Turns out my Sony DA50ES was causing the annoying hiss!

So anyway, I hooked up my new Denon 2313 (Factory Refurbished from Accessories4less.com $450), and the background is completely silent! I also wanted a good power cord, and used Emotiva's X Series IEC.

I still need to fine tune the audio, and see what all this room calibration buzz is about!

Here is my current setup:

Denon 2313
Sony 470 Bluray
AppleTV
Monoprice HDMI Cables
Kimber Kable Quick12 speaker wire
Emotiva power cord
Axiom Audio M22 inwall speakers
Klipsch KSW-12 Sub
Samsung PN50C7000