I assume we're talking about a UMC-200 here...?
In "situation #1", it would depend on
WHAT MODE you have selected on your UMC.
For example, if you're in Direct Mode, then the analog coming in the input (from the Oppo's analog output) is being passed directly to the Volume Control and then out - so you're hearing the DACs on the Oppo - with no conversions being done by the UMC.
HOWEVER, if you select Stereo Mode, then that same analog input on the UMC is being converted back into digital, fed through the processor, and then converted back into analog. (In Stereo Mode you get to use the room correction, which requires that the signal be converted back into digital since room correction is a digital processing function.) In that situation, you are listening to
BOTH the DACs on the Oppo
AND the DACs in the UMC (you are getting any colorations or distortion introduced by each DAC - added together and limited by the worse of the two). In that case, you'd be better off using a digital input, and
JUST the DACs in the UMC.
The reason why some of us prefer to use the 7.1 Inputs is that they are "locked" into Direct Mode; so you
CAN'T pick a mode for them that is anything other than Direct Mode - even by accident.
There are other factors at play in situation #2. For example, by connecting the DAC at the end of the signal chain, you are in principle allowing that "final DAC" to control how the analog audio sounds (in that case you would use a digital connection between the source and the UMC). The limitation there, however, is that the processor is still changing the bits that make up the digital audio. This is happening for two reasons. First, because
ANY processing requires that bits be changed. The other reason is because of the legal requirements of HDMI copy protection. When the UMC (or any other pre/pro) converts digital audio it receives via HDMI into analog, it does so at the full quality in which that audio is received.
HOWEVER, the digital audio it sends out via Coax, or Toslink (or any other way digitally
EXCEPT HDMI) has been downsampled. (This is a nice way of saying that the HDMI standard doesn't
ALLOW us to take the digital audio we received via HDMI and send it out via any other digital method without deliberately reducing the quality. This requirement is there to prevent evil users from recording that digital signal and making illegal full quality digital copies of it; it is part of the standard, and nobody is legally allowed to circumvent it.) This means that, unless your DAC has an HDMI input, if you connect your DAC to the output of the pre/pro, and your source is HDMI, it
WILL be receiving a reduced-quality signal to convert. This gives the UMC the "home field advantage". There are similar restrictions on SACD (we aren't legally allowed to give you
ANY digital audio output from SACDs.)
The upshot of all this is that the way the vast majority of audio purists do it is to connect the analog outputs of the Oppo to the 7.1 analog inputs on the UMC in addition to the digital HDMI video connection. Then , when you pick that input, you are listening to the Oppo's DACs - with no conversions and no processing by the UMC. (You can then use that input to listen to SACDs, or any other digital audio, through the Oppo's DACs.)
Since the Oppo 95 uses Sabre DACs, which do have a distinct "sonic signature", you may or may not like the way they sound better than the DACs in the UMC. However, that is a matter of personal preference.
I have 2 questions--One about inputs--specifically analog vs. 7.1 and the other about DACs and where they fit in the system chain.
Situation & Question #1--I had my OPPO 95 plugged into a set of analog inputs on a UMC-200 for 2 channel sound. I was under the impression that the OPPO DACs were processing my music but was told by numerous members on our forum that the UMC DACs were processing because I had the OPPO plugged into analog inputs on the UMC. I was told that I needed to plug the OPPO into the 7.1 inputs on the UMC for the OPPO to process. I'm not disputing that this correct, just giving some background information. Question-Is this correct?
Situation & Question #2--Thinking about situation #1, does it matter where an external DAC is located in the system chain? Seems like it would. Is the proper order: source=>external DAC=>processor=>amps? or is it source=>processor=>external DAC=>amp. Or is the order not important as long as the proper inputs are used?
Keep the answers simple. My brain can't handle a lot of tech talk. Just the simple facts-yes, no, etc...
