Neither connection is optimum for this since you will be getting a mixdown either way UNLESS you select a stereo track from the BRD.
My toslink cable is a Wireworld Supernova 6 glass toslink, it goes into the toslink input of a Wadia 860x cdp (which in this case is serving as a digital "pass through") and then out via Kimber Select 2120 xlr digital coax to a Weiss Dac2 (the Weiss doesn't have a toslink input).
FWIW, Oppo has just replied to my inquiry, they say to use the analog stereo outputs rather than toslink. They say that way I can use the Dolby Digital TrueHD or DTS-HD formats.
But, you're right, I'll just have to try it both ways. I had assumed that by utilizing my outboard dac I would get superior sound. I'll have to try the settings for the analog outputs and see what happens.
It makes no sense that this is a question at all via you are not running surround format.. 2 Channel the easy answer is regardless of format, 16 bit 2 channel stereo vs. 24/196 for a movie going thru 2 channel systems matters not.
Take a connection to your DAC which should be far superior using the oppo as a transport running 2 channel which bypasses all the decoding B.S. in the unit, and run a 2 channel analog line separate into another input on your preamp and then you can compare which you like better by hitting a button to switch on the fly between them both. I would test this running standard 2 channel CD, and DVD movies, Movies I can guarantee will make virutally no difference, however CD for music should be superior thru your DAC setup via optical considering you have some top grade gear with wadia and Weiss.
This is the easiest and best A-B test you can do, then you get to hear the oppo as it translates the format and without even getting up from your chair or changing the music get a nearly instant comparison on drums, vocals etc...
Thru both D-A convesion methods.By the way Blu-Ray concert DVD's are far superior from my testing running thru a good DAC in 2 channel. Otherwise you need some seriously good multi channel systems to beat a superior 2 channel setup, not that it can't be done, but you gotta fill a room with a lot more speakers, wires and gear to come close. And room acoustics become even a bigger mess to get right. Don't get all caught up in the hype of high numbered D-A conversions etc..
It all comes down to how well that Blu ray or CD or SACD was mixed and produced on the recoding itself and how it ends up sounding on what your equipment is superior at re-producing not what the specs. say trust me on this.
I haven't done the A/B listening yet, my Oppo and my stereo rig are 3 meters apart. I have the 3 meter glass toslink, not the 3 meter analog ic's. I thought I'd get some opinions before I sprang for a pair. BTW, I won't be using the Oppo as a cdp, I have the Wadia 860x for that. The Oppo will be used for blu-ray & dvd, many of which are concert recordings. Thanks for your input!
Thats fine, I understand you have some hi end gear and cables, which means you can easily hook up the toslink and not the analog, I just highly suggest you still try it this way even with 6 dollar 3 meter walmart/radio shack analog cables to get an idea if you are really looking for blu ray being better thru the DAC or oppo.. I would just run the optical to your dac, bet is it will be just as good or better.
With blu ray specifically I have not found this to be true, in movies it may have a slight effect on dialog, however 100% of the blu ray "Concert DVDS" specifically I don't have a single one that does not come with a 2 channel downmix in the menu..
Acutually from my experience so far with my setup which in the past was not true of standard DVD blu ray 2 channel even thru the digital outs does not vary at all from the multi-track option. Why? Not sure accept that in the new technlogy and format of making the blu ray discs they have seemed to somehow auto-sense regardless and your front 2 main channels are going to always be mixed with full range frequency.
Again this is not true with DVD, for example I can take your new Harry potter Blu ray or whatever which has Zero audio options but true HD surround or whatever and put it on with NO subwoofers, No center channel, and just running on the mains I still get as good or better explosion impact, and dialog with less channels and equal to running it thru HDMI to a multi channel processor! Since these revelations and the importance to me in specific of do I care as much about Transformers making it as accurate sound as possible like a mountain coming down in my house? I have decided movies are not that critical and the concert DVD's and music is far more necessary to get the attention and money.
Again this was never the case with Standard DVD, and definitely a KILLER with concert DVD's that if you were running the concert in 5.1 or 7.1 it sounded very hollow or totally aenimic in power output compared to using the 2 channel mix.
I am sure depending on the source, the processor, etc... This will all vary system to system to some degree. Again today digital has advanced far beyond 5 or 10 years ago and is cheaper, less and less issues with audio mixes have been the normal in my case recently with new releases over the past few years.
Sounds like you should use the digital out then.
I am doing the same with my Blu-Ray/HD DVD player with two channel PCM output over coax into my EMM Labs XDS1 CDP and it works extremely well. There is no need for a two channel specific track in your Blu-rays, every Blu-Ray player will down mix a multichannel Blu-Ray lossless soundtrack properly to two channel and should output to PCM 24/96 over coax or toslink for processing by a DAC. Further, the Oppo is said to offer a superior two channel down mix.
Of course you can, as long as you set the oppo in the audio menu to 24/96 as your output on the digital outs, you should have an option to out at least 16/48, 24/96, and I am not sure with the new oppo model but probably has capability to even output and upsample anything to 24/192...Which by the way it will upsample even a 16/44 CD to 16/48 or 24/96 with no problem as well so you can try it all ways to find out what you like or don't like about each.
However the second half of the equation and more import is does you dac truly support 24/96 or 24/192 at the input? Also you could have an upsampling DAC which means it takes the 16.44 or 16/48 signal from your transport and does its own upsampling automatically or by a switch on your DAC unit depending on the make and design. Also if your Dac only accepts a standard 16/44 or 48 at the input receiver chip and you set the oppo to output a higher rate it may reject it and not lock on at all meaning you could get a bit of a nasty sound thru your speakers or not work at all.
You will have to experiment to see what works best on your end unless you already know all your gear is capable.
Here's what Oppo says in the manual:
"Due to bandwidth limitations, high resolution audio formats such as Dolby Digital plus, Dolbt TrueHD, DTS-HD High Resolution and DTS-HD Master Audio cannot be sent through the coaxial or optical digital output. A reduced resolution version of the same audio track will be output instead."
"The stereo audio out terminals (analog) will always provide a down-mixed stereo signal from multi channel sources. The "Down Mix" and other speaker settings in the Audio Processing Setup Menu do not affect the (analog) Stereo Audio Out."
And there is this from Oppo's customer service:
"For the best audio in a two channel configuration you will want to use the dedicated stereo output of the BDP-83. Digital coaxial or optical will use the lossy, Core Dolby Digital and DTS from Blu-rays, which is inferior to the DTS-HD Master and Dolby Digital TrueHD you can get from the analog outputs."
I take all this to mean that there is reduced resolution audio from the digital optical output. Now, that digital output would surely benefit from being processed in an outboard dac. However, they are also saying that lossless formats such as Dolby Digital True HD and DTS-HD Master can be output through the analog stereo outputs, but through a downmix if the original format was multi-channel. Obviously the only way to put this to rest is to do an A/B comparison, AND one has to make sure that the settings in the Oppo's audio menu are correct for each format.
BTW, SACD will play through either HMDI or the analog stereo output connections only.
Am doing the A/B listening now, connected the analog outputs with a 3m pair of Kimber Hero's. So far, the toslink into the Weiss Dac2 (it does have a toslink input after all, duh) sounds better than the analog output direct to the preamp, which does not utilize the outboard Weiss dac. When you switch back & forth, the toslink connection is quite a bit louder and I have to adjust the volume as I do so. The toslink connection sounds more dynamic, I would imagine due to it's connection to the dac. The analog connection seems a little more laid back, possibly with a bit darker sound. I'll have to do some more listening, and be sure my audio setting are correct.
Thanks to all!