RSP 1068, analog or digital in stereo mode?

[bleeding ears]

Hi guys, after reading the technical section notes under FAQ on the rotel site, it states the rsp 1066 in stereo mode is analog apart from the subwoofer signal.

My question is, is the 1068 also analog in stereo mode ?

The reason I'm thinking it may be different to the 1066 is that the 1068 has a bypass mode which is pure analog bypass.

I cannot see any point in both Stereo mode and bypass mode on the 1068 both being analog, or am I missing something.

Anyone know ?

Thanks Pete

[chinets]

Press the stereo button twice and that should flip the Stereo mode into Bypass mode. At least that is what I do with my Rotel 1098 processor, and it works that way. No stereo mode is not the same as pure Bypass mode ,again at least not with the 1098!! The 1098 also has a single Bypass mode button and an extension button which are all Bypass ways to get to Pure Bypass made. Press the Stereo button twice and Volia you get Bypass mode too ,but in Stereo ONLY!!
Good Luck and let us know your results!!
Cheers.

[bleeding ears]

chinets, yes, if I push the 2 ch button on remote the unit switches to bypass mode, no problem there.

Yes the two modes (stereo and bypass) do sound pretty different. I know that bypass mode doesnt send a signal to the sub and the speakers are given the full range signal, no problems there either I understand all that

But what I really do not know is, is stereo mode analog just like bypass mode is, or is the entire signal in stereo mode digitised within the processor.

I cannot see any point in having two analog modes, so I would guess that stereo mode gets the dsp treatment. (not just the signal sent to the sub)

However I could be wrong, hopefully someone can clear this one up for me ?

Pete

[Kevin D]

The stereo mode is digitally manipulated. I'm not sure why they would say the 1066 is full analog apart from the sub, because the bypass feature of the 1068 was a highly touted upgrade from the 1066. If there was no difference between a 1066-no sub and a 1068-bypass I'm not sure why it would have been a big deal.

Kevin D.

[bleeding ears]

Kev, as I am sure you are aware, the 1068 in bypass mode, bypasses all tone controls and doesnt create a seperate sub signal so I guess it is also so called "pure analog".

Just not sure about the stereo mode and whether it is just the sub signal that is digital or if the whole sound range is digitally manipulated.

It would be nice if Rotels web site provided a technical description for the 1068 as it does for the 1066.

Thanks Pete

[srb]

I'm pretty sure that my RSX-1056 Receiver operates in exactly the same way as the RSP-1068 Pre-Pro.

I believe that the Stereo mode is a complete ADC to DAC re-conversion.

My analog sources sound better in Bypass mode than in Stereo, and I have verified this in numerous A/B blind tests with 100% correct identification.

The Stereo mode has a little less clarity and a slight roll-off in the high-end, and the dynamic range and attack are somewhat reduced.

Try switching back and forth between Bypass and Stereo without looking or remembering which mode you are in, and see if you come to the same conclusion.

[bleeding ears]

srb, I have many times switched back and forth from stereo to bypass and compared the sound of each.

I have also purchased and then resold an older but top of the line Rotel 990 preamp and made comparisons.

The comparisons were all done using exactly the same setup, same speakers amps cables and sources.

The conclusion I came to was a bit different to yours.

I firstly found that the 990 preamp sounded similar to the bypass mode on the 1068, but maybe just a little fuller sounding on the 990, not much in it.

Secondly I found the stereo mode on the 1068 to sound a bit thinner and maybe not as big sounding (soundstaging I think is the term used) as bypass on the 1068,but overall I favour the stereo mode over the bypass mode and the 990 preamp. It is like the 990 preamp and bypass mode on the 1068 are a bit too full and too bassy sounding for my liking.

I cannot totally understand why I found stereo mode to better the bypass mode and the 990 preamp, but I suspect it has something to do with the speakers Im using and my room which is not particularly good for sound.

Stereo mode enables the use of tone settings and small or large speaker setting and the use of a sub. These adjustments and settings may be responsible for the better sound I get.

I think that this may not always be the better sounding mode, depending on what speakers and other factors you may have in your setup and your listening room.

The better sounding mode (stereo or bypass) may vary depending on the disc being played, and when trying different speakers (borrowed from a mate)bypass mode seemed to beat stereo.

I guess the bottom line is, use the mode or the equipment that sounds best for you. It is good to know that overall the 1068 was not too far behind, or in my case sounded better in stereo mode than the top Rotel stereo preamp.(my preference only)

I still am not sure of whether stereo mode on the 1068 is completely digitally processed or not, and I guess it doesnt matter too much, it all just makes me interested in what sort of sound quality is possible with digital processing over straight analog for stereo. Hence my original post.

Pete

[chinets]

Bleedin Ears,

Simple as that:

"In Stereo you get it digitalized with your processor. In Bypass Stereo mode ,you get your CD Player DACs, and it is pure analog ,and no processor interfrerence.!!
That's it!!!"

Hope that helped!?

Cheers!!

[srb]

Stereo mode enables the use of tone settings and small or large speaker setting and the use of a sub. These adjustments and settings may be responsible for the better sound I get.

I think that this may not always be the better sounding mode, depending on what speakers and other factors you may have in your setup and your listening room.[

Yes - my comparisons were without tone controls and sub.

I think my most noticeable "artifact" that I spoke of was probably the attack of instruments...the leading edge was slightly rounded off, making it less realistic to me.

That may have something to do my speakers, which have ribbon tweeters. They are very smooth, but quite revealing.

The fact that you found the 990 preamp less to your liking (and got rid of it), makes me a little nervous to try a preamp in my system.

I have considered trying one (with HT bypass input), but aside from the hoped-for improved sound quality, a big reason would be that my power amp is dead quiet, but the RSX-1056 is not. What particularly irks me, is that the rear (and center) speakers are NOT muted in Bypass mode, and can be heard in quiet passages, as the rear speakers are only about 3 feet from my listening position.

[PewterTA]

Chinets stated it exactly...

If you are using the 2ch Stereo mode on the 1068 then you are dependent upon the DACs of the 1068 to "interpret" the sound. Now if you have a better DAC on your CDP, then 2ch stereo mode is NOT what you are wanting to use as it's degrading the signal that the CDP is sending. By 'degrading' I don't mean it's ruining the sound, it's just manipulating it (most times - in case of a good DAC on your CDP - for the worse).

So you are better off using the bypass mode when the signal goes into the PRE and is only manipulated digitally for volume. This *should* give you the best sound but will only be as good as the DACs on your CDP.

...but really it's all just a personal preference as to what type of sound you like.

[srb]

Chinets stated it exactly...

If you are using the 2ch Stereo mode on the 1068 then you are dependent upon the DACs of the 1068 to "interpret" the sound.

Actually I was referring to analog sources that have no digital output (or a digital source that has a better sounding DAC than the Rotel receiver/pre-pro, and you are going to use the analog output).

In my case, one of my sources is an iPod with Apple Lossless, which has no digital output. The built-in DAC of the iPod does the D/A conversion. But if I enable Stereo mode in the processor, I am re-sampling and performing a 2nd D/A conversion.

In this case, the Stereo mode will give tone control and a subwoofer, but there will be deterioration from dual Digital > Analog > Digital > Analog conversions.

[Nolan B]

Actually I was referring to analog sources that have no digital output.

In my case, one of my sources is an iPod with Apple Lossless, which has no digital output. The built-in DAC of the iPod does the D/A conversion. But if I enable Stereo mode in the processor, I am re-sampling and performing a 2nd D/A conversion.

In this case, the Stereo mode will give tone control and a subwoofer, but there will be deterioration from dual Digital > Analog > Digital > Analog conversions.

On a side not your best bet is to send a pure digital signal from your Mac to your 1068 and not use the Ipod or Mac DACs at all. I recently bought a Transport which alows a digital signal from my Mac and in Apple Lossess it does a great job. Its a worth while $100 upgrade.

[srb]

...your best bet is to send a pure digital signal from your Mac to your 1068 and not use the Ipod or Mac DACs at all.

Why would you assume my computer is a MAC?

My old and noisy PC is in another room, and although I could get a Squeezebox or similar to control it, I will soon be getting a very quiet HTPC + external DAC to go in the equipment rack, and the iPod will only see portable and automotive use!

[Nolan B]

Why would you assume my computer is a MAC?

My old and noisy PC is in another room, and although I could get a Squeezebox or similar to control it, I will soon be getting a very quiet HTPC + external DAC to go in the equipment rack, and the iPod will only see portable and automotive use!

lol..why would I assume its a PC? An iPod is a Mac product. Yes it can work with PC, but with the limited info i got from your other post assuming you had a mac is more likely. When it comes to playing/managing music from a Comp its been my experience that Mac is better and more widely used. That is just from my own personal experience and not marketing numbers.

Guess I was wrong.

[bleeding ears]

Thanks for the replies guys, Srb, if considering a 2 channel preamp, you may get better results than I did.

Although the difference with the 990 preamp over bypass mode on the 1068 was not much in my setup, I did test the 990 preamp out at a mates place and it seemed to come to life, so to speak, and sounded pretty good.

I dont know why this didnt occurr at my place with my setup but once again my mate uses different speakers in a different room, but still uses a Rotel 1066 pre/pro and Rotel 1075 amp.

Best to demo any gear at home if possible before purchasing, upgrades could be a small improvement for a lot of money.

chinets, I dont use the digital output on my player for cds.

I use the analog outputs so yes, in bypass mode I would be hearing the dacs in my player, which is a Onkyo 555 dvd player.

In stereo mode on the 1068 (with analog input) I was not sure whether the signal was undergoing another analog to digital conversion and then another Digital to analog conversion in the processor,which from what has been said IS apparently what is occurring.

To tell the truth I still have my doubts about it, there seems to be little point in an extra A/D conversion within the processor and then another D/A conversion within the processor before the signal goes out to the amp, when the incoming analog signal could just be transferred straight out to the amp without these extra conversions.

Might be best if I get some clarification straight from Rotel on this.

I will send them an email and get back with what I find out.

Thanks Pete

[Kevin D]

To tell the truth I still have my doubts about it, there seems to be little point in an extra A/D conversion within the processor and then another D/A conversion within the processor before the signal goes out to the amp, when the incoming analog signal could just be transferred straight out to the amp without these extra conversions.
Thanks Pete

For the 1068 to apply any manipulation to an analog signal it must be in the digital domain. This applies to extracting sub info, applying crossovers, tone control, running through a surround mode, etc..

So even if none of that happens (no surround, no sub, fronts set to large, flat tone) it's still going to go through the process. It would make less sense for it to pass analog only if none of the adjustments above are applied, rather then just give people the bypass choice.

Kevin D.

[bleeding ears]

Ahh, thanks again Kevin, it is all starting to make sense.

As you can tell I do not have the best understanding of the circuits etc and how they work within the processor.

I am fascinated by how these things work and how one model may differ from another, and also why Rotel makes changes in newer models over what may have been a very good sounding processor or receiver in the first place.

thanks all for your explanations and patience.

Pete