I'm considering an Onkyo PR-SC885P...

[timjclark]

Hello,

I'm considering an Onkyo PR-SC885P to replace my HK AVR430. I'll be using Proceed AMP3 & AMP2 going to my B&W 640's.

From all that I have read, the 855/9.8 are just outstanding units.

My B&W dealer also sells Rotel and has suggested that the 1098 that he has would be a very good selection for me. Of course, that unit is too pricey for my budget ($1000) and does not have any HDMI which would mean no TrueHD/Master Audio from my PS3. The Rotel 1069 would give me these codecs decoded in the player which I'm thinking would be fine for me.

Has anyone here had the occasion to compare the 855/9.8 with either the 1069 or 1098? My interest is in sound quality - that is far more important to me than video processing.

One last questions, does anyone know if the XLR connections on the 9.8/885 mean that the unit has truly been designed from a balanced approach inside or are these connections here simply for convenience sake for users who need them?

This forum is rather quiet, is anyone here?

Thank you,

Tim

[Glen B]

At its price level, with all its features and 7.1 channels, its highly unlikely the 855P is of true differential topology with 7.1 channels. Except for a single pair of XLR inputs, the remainder are RCA, so at least we know there are no differential inputs for those channels. I believe the unit is employing OP-AMP converters to achieve balanced outputs.

[timjclark]

At its price level, with all its features and 7.1 channels, its highly unlikely the 855P is of true differential topology. Except for a single pair of XLR inputs, the remainder are RCA, so at least we know there are no differential inputs for those channels. I believe the unit is employing OP-AMP converters to achieve balanced outputs.

Hi Glen,

I have to admit, that I do not know anything about differential topology... So, if this unit is unlikely to have differential topology, how would one get the best sound of out of it: the RCA's or balanced? Or is a case of try it and see?

Thanks much!

Tim

[Glen B]

You could try both XLR and RCA connections and see which you prefer (if there is an audible difference). However, that would mean investing in two compelete sets of cables. The XLR connections would be most useful in reducing noise pickup if your amplification is some distance away and has balanced inputs, otherwise, it better to stick to RCA.

With true differential topology, the positive and negative halves of the audio signal (a.k.a. non-inverted and inverted halves) are processed independently by mirror-image circuitry from input to output.

With equipment that is not of true differential topology but has balanced inputs/ouputs, the two halves of the audio signal are combined by an OP-AMP immediately after the input, the signal is processed by single-ended circuitry, then converted back to balanced at the output by another OP-AMP converter. This conversion process adds extra circuitry, and may add possible sonic artifacts of its own, and distortion.

[timjclark]

Thanks for that explanation Glen - now I get it! The interesting thing is that the input on the Proceed PRE for it's Tape2/SSP bypass is RCA only - no balanced option. So if I'm running RCA from 855 to the PRE, it would probably make no sense to run balanced to the AMP for Center and the rears.

At present I am using the balanced connection from PRE to AMP for my 2-channel as I am running balanced from my Proceed PDP into the PRE. I'll probably leave that as is although I bought some ZU Cable XLR cables a few years back but I have no idea how good those actually are.

The idea of running all balances seems so tempting until you think about what that probably means is going on in the signal path. Thanks again!

[Kal Rubinson]

At its price level, with all its features and 7.1 channels, its highly unlikely the 855P is of true differential topology with 7.1 channels. Except for a single pair of XLR inputs, the remainder are RCA, so at least we know there are no differential inputs for those channels. I believe the unit is employing OP-AMP converters to achieve balanced outputs.

So?

Such balanced outputs are as effective for providing immunity from induced RF noise as the balanced outputs of fully balanced designs.

Kal

[Kal Rubinson]

With equipment that is not of true differential topology but has balanced inputs/ouputs, the two halves of the audio signal are combined by an OP-AMP immediately after the input, the signal is processed by single-ended circuitry, then converted back to balanced at the output by another OP-AMP converter. This conversion process adds extra circuitry, and may add possible sonic artifacts of its own, and distortion.

Hardly relevant for digital inputs.

[Glen B]

So?

Such balanced outputs are as effective for providing immunity from induced RF noise as the balanced outputs of fully balanced designs.

Kal

Did I say they were not effective ?

Hardly relevant for digital inputs.

Did I miss something ? The inputs are analog.

[Kal Rubinson]

Did I say they were not effective ?

No, you did not but the tone of your comments indicated a dismissive attitude towards bal outputs not derived from a truly balanced component.

Did I miss something ? The inputs are analog.

Some are and some are digital. The OP was somewhat vague in his question when he asked about "XLR connections" but the rest of his post seemed to deal with the HDMI input.

Kal

[timjclark]

Kal & Glen,

The input sources that I will using on the 855 are: comcast HD cable box with HMDI, PS3 with HDMI and a Yamaha DVD player with component and RCA digital audio. Part of my excitement over the 885 over other SSPs is the presence of the balanced outputs as my Proceed AMP's have balanced inputs. At first I was thinking, if it has balanced outputs, then I should use them and my system would be better. I gather that this might or might not be true - I'd have to try it and see.

Right now, I'm using component + TosLink from the cable box into my HK. I was thinking that moving this to HDMI would be best to avoid video conversion from component to hdmi.

I'm guessing there is not a firm answer to these questions for any system: always use balanced over rca; and always use HDMI over component.

My plan is to have the SSP and the AMPs in the same equipment rack, so the RCA or XLR runs will be 1 to 1.5m. I could move the amps below my TV at which point the cable runs would be more like 5 to 6m. I suspect if I were to do that, then XLR would make more sense.

CURVE BALL:
I am wowed by what the 885 offers for the price (HDMI 1.3, balanced output, latest codecs, enough inputs to choke a goat). But I also like the Rotel 1069 (it has HDMI 1.1 which is a wash with the PS3 and decoding TrueHD/Master audio; I prefer it's looks, more refined?). I have not heard either of these units in action. I am leaning toward the 885 for it being totally up to date, but I wonder if the Rotel might sound better.

Kal, might you be able to opinions on my 1069 vs 885 debate?

Thank you all for your input!
Tim

[Kal Rubinson]

The input sources that I will using on the 855 are: comcast HD cable box with HMDI, PS3 with HDMI and a Yamaha DVD player with component and RCA digital audio.

So I figured, in principle.

I'm guessing there is not a firm answer to these questions for any system: always use balanced over rca; and always use HDMI over component.

Like most generalizations.

Kal, might you be able to opinions on my 1069 vs 885 debate?

Nope. Don't know the Rotel.

Kal

[wettou]

So? Such balanced outputs are as effective for providing immunity from induced RF noise as the balanced outputs of fully balanced designs. Kal

I don't think so I switch my RCA and Use an XLR with my sub and the noise coming from the sub was obnoxious!!!!

HELP why would that be

[Kal Rubinson]

I don't think so I switch my RCA and Use an XLR with my sub and the noise coming from the sub was obnoxious!!!!

There's something amiss in your ground loop situation. There's no way that you would have less noise with an RCA unless the RCA's ground connection is necessary. It has nothing to do with RF-induced noise.

Kal

[arashjahn]

XLR Inputs on 885P

So?

Such balanced outputs are as effective for providing immunity from induced RF noise as the balanced outputs of fully balanced designs.

Kal

So the inputs are the same topology as the more expensive preamps on the market? From the sound of your post, it seems it is only the outputs on the 885p that are not true differential topology.

Thanks,
Arash

[madmac]

Kal & Glen,

The input sources that I will using on the 855 are: comcast HD cable box with HMDI, PS3 with HDMI and a Yamaha DVD player with component and RCA digital audio. Part of my excitement over the 885 over other SSPs is the presence of the balanced outputs as my Proceed AMP's have balanced inputs. At first I was thinking, if it has balanced outputs, then I should use them and my system would be better. I gather that this might or might not be true - I'd have to try it and see.

Right now, I'm using component + TosLink from the cable box into my HK. I was thinking that moving this to HDMI would be best to avoid video conversion from component to hdmi.

I'm guessing there is not a firm answer to these questions for any system: always use balanced over rca; and always use HDMI over component.

My plan is to have the SSP and the AMPs in the same equipment rack, so the RCA or XLR runs will be 1 to 1.5m. I could move the amps below my TV at which point the cable runs would be more like 5 to 6m. I suspect if I were to do that, then XLR would make more sense.

CURVE BALL:
I am wowed by what the 885 offers for the price (HDMI 1.3, balanced output, latest codecs, enough inputs to choke a goat). But I also like the Rotel 1069 (it has HDMI 1.1 which is a wash with the PS3 and decoding TrueHD/Master audio; I prefer it's looks, more refined?). I have not heard either of these units in action. I am leaning toward the 885 for it being totally up to date, but I wonder if the Rotel might sound better.

Kal, might you be able to opinions on my 1069 vs 885 debate?

Thank you all for your input!
Tim

The Rotel will sound better. However, Rotel is behind in the HDMI and connectivity aspect of things. But they sound damn good!.