Are the Dacs of 1072 equal or better to Dacs of 1098??

[chinets]

Hi Everyone,
Are the Dacs of the Rotel 1072 cd player equal or better than the Dacs of the Pre/Pro Rotel 1098 or Vise Versa or just the same????????.Thanks,
Chinets

[Aussie Geoff]

Chinets,

I have both and have done extensive comparison by having the RDC-1072 connected as two devices, the CD for analogue and a second for digital - allowing instant switching...

Bottom line - the RCD-1072 DACs are better at decoding CDs than the RSP-1098 by a significant margin... However you need to be in pure stereo to get tis, since soon as you activate the subwoofer or go multi-channel the RSP-1098 will re-digitise the sound.. It is also very cable dependent. For example a very good digital cable (like Cat Cables’ pure silver digital) can allow the RSP-1098 to sound amazing via the digital input of the RCD-1072, but a very good analogue cable (like Silver KingCats from Cat Cables) can make the RCD-1072 sound sublime....

This shouldn't be a surprise - the RCD-1072's DACs are optimised just for the 44.1 16 bit signal of CD and do the procesing tricks like oversampling etc to get optimal sound out of the CDs, while the RSP-1098 needs to deal with all sorts of sampling frequencies abd sizes(and does it very well).

So I have left both active - I use the analogue for pure stereo and the digital for everything else!

Geoff

[chinets]

Geoff,
WoW, Thanks for your detailed Info. I am learning here, and you have given me some great insight into this.
Thanks,
Chinets

[bleeding ears]

Geoff, does the 1098 have the bypass mode and multi bypass like the 1068?

Also what speakers do you run?

Pete

[BWzes03]

Geoff, does the 1098 have the bypass mode and multi bypass like the 1068?

Also what speakers do you run?

Pete

Actually, the RSP-1098 introduced the bybass feature...

[bleeding ears]

Ok so let me get this right! , if you dont use the analogue bypass, the analogue output from the cd player gets converted back to digital in the processor and then back to analogue again before it goes out to the amp?

If not using bypass, would this double conversion negate the benefits of using a good cd player?

Would the benefits of a good cd players dacs be overridden or affected by the dacs in the processor?

Would it be better if not using bypass to use only the digital out of the cd player? as it reduces the number of conversions from digital to analogue and back again?

What is best?

Pete

[Stev]

Pete.
I have my 1072 connected by coax and analog and find the SQ to be better with the double conversion than when I switch to the coax to remove a conversion. I choose not to use the bypass mode as I prefer to use a sub to suppliment the bottom end of my mains - with a tight sub this gives me by far the best result even tho it requires the 1072's analog out to be converted back to digital to get a sub signal.

Steve

[bleeding ears]

Stev, thats very interesting.

What processor are you using?

If it is a Rotel 1068 your sub WILL still work when using the multi bypass connections on the processor. Using only the FL and FR connections.

I just tried it.

It is only the bypass obtained using the regular cd inputs on the processor that wont allow you to use the sub. (the bypass you get by re pressing the 2 ch button on the remote)

So you can actually use the bypass and use your sub.

whether this beats the sound of the digital lead and the sub, or the analog leads and the normal cd input,I dont know, perhaps you can tell us?

I guess its good to have options to try which you prefer.

Not sure if the 1098 procesor is exactly the same or not.

Pete

[BWzes03]

I guess it is a matter of taste coupled with the circumstances of the set you use the player in.
I find that the Digital out of the RCD-1072 coupled to the RSP-1098 is very close, but not the same as the analog out of the player to the processor in bypass-mode.

I find the SQ, in my situation to be better using the analog-out to the processor in bypass mode.

When switched to "stereo", the processor will digitize the analog input, in order to process the "contours" (bass/treble balance) and subwoofer cross-over circuits.
In my situation this degrades the SQ slightly, as I have no subwoofer in my setup.

Coupled with the fact that I found the analog output to be superior to the digital output, should your setup need a subwoofer to support the fronts in stereo, your best bet is to go with the analog-outputs and have the RSP-1098 redigitize the signal rather than use the digital-output.

This is probably due to the DACS in the player being dedicated to Redbook decoding. This produces a superior analog signal, which is then redigitized in the RSP-1098 using the higest sample-rate it can use (my guess is 24bit/96KHz..(or 192KHz I'm not sure)).
Compare this to a digital input signal from the player at 16 bit/44.1KHz.

Your personal mileage may vary though..

[Stev]

Pete,
I have the 1056 as a processor feeding a 1075 biamping my mains. To my understanding the 1056 is the same in all repsects as the 1068 in processor and menu/features wise. I have the analog multi input connected to my universal dvd player for sacd/dvda. To get a sub signal as you suggest do you have the LFE redirect on ? I've not tried this but I assume this is how you would get a sub signal. Depending on how your xover's are configured this could give a full range signal to your sub. I have the sub xover off with all my speakers xover at 80hz - this sends all bass sent to speakers below 80 hz to the sub and also a full range signal to the sub. I use the sub's own xover to filter the full range signal the Rotel is sending it. This works better in my setup than setting the sub xover to defeat and using Rotel sub xover setting. The xover options in the Rotel's are great for helping to acheive a flat response but you can go backwards with the advanced settings untill you really get a grasp of what your actually changing.

Steve

[bleeding ears]

Stev, yes I have LFE redirect "ON" when using the multi bypass connections.

Keep in mind,that I am not playing dvd-a or sacd (yet) and hence only use the FR and FL speakers/connections.

When using the multi bypass FL FR the only function that operates is the LFE redirect, and the sub crossover I think?

I have found that I can alter the crossover setting for the front speakers but it does not seem to change the sound from the fronts I assume the crossover function for the fronts becomes inoperative when using multi bypass, even though the menu shows the setting as changing. Not sure about that still trying it.

From my listening, I am of the impression that all the speakers (if you have them all running) will get a full range signal even if they are set to small, unless you use the LFE redirect.

It seems that changing the menu setting to small speakers does nothing, they all run as large I assume, and it certainly sounds like it judging by the bass I get.

I really needed the LFE redirect on to help control the bass.

I am talking about cds here, if you are playing a dvd-a or sacd, I believe you should have some bass management at the player and can alter settings there if need be.
Playing cds there is no ability to alter contour settings, when using the Multi bypass.

The bypassing of the contour settings etc in multi bypass mode gives a very full rich sound that is not there in stereo, however the inability to make small adjustments, for me is a problem.

I am considering running a 2 channel preamp with tone controls,thru the multi bypass FL FR to see what I get.

I will then be able to adjust bass and treble and I am still keeping the sound away from the digital processing in the 1068.

You are right, you can go backwards with all these options.

I try everything out of curiousity and then try to stick with what sounds best.

Things can get very complicated with all the settings on the 1068.

Sorry if we are a little off the orig topic but it is all related.

Pete