XMC-1 analog inputs

[saru]

It's time again for my "dumb question of the week!" 

While I await the repair and return of my XSP-1 from Emo HQ, I have relocated my Schiit Gumby to the home theater, where I've got it connected to the XMC-1's balanced analog inputs.  From what I understand of the XMC manual, music played through the analog input should be processed only by the external DAC and simply passed through the XMC as long as the XMC's mode is set to Reference Stereo or Direct.  Of course, this means that Dirac and other processing in the XMC is also bypassed (except for bass management in Direct) -- however, I've noticed that music played in this configuration in my theater room sounds REALLY bad!  Apparently I have more work to do with acoustic treatments...  meanwhile, engaging Dirac via Stereo mode fixes the issue and the tunes sound sweet as honey again.  

Now, my question is this:  if the analog signal coming in from the Gumby is converted back to digital in order to apply the Dirac processing and then converted back to analog on its way out to my amps, then does that mean the resulting sound is more representative of the XMC's DAC than the external DAC?  This distinction is important because, if I continue to prefer using Dirac over non-Dirac for 2ch listening in the theater, then it might not make sense for me to employ an external DAC in that system if its effects will be largely overridden by the XMC's internal DAC.  Not that I'm planning to keep the Gumby in place -- it's going back to my office when the XSP gets back from service -- but it will inform future purchasing decisions.

[monkumonku]

Mar 24, 2017 11:06:22 GMT -5 saru said:

It's time again for my "dumb question of the week!" 

While I await the repair and return of my XSP-1 from Emo HQ, I have relocated my Schiit Gumby to the home theater, where I've got it connected to the XMC-1's balanced analog inputs.  From what I understand of the XMC manual, music played through the analog input should be processed only by the external DAC and simply passed through the XMC as long as the XMC's mode is set to Reference Stereo or Direct.  Of course, this means that Dirac and other processing in the XMC is also bypassed (except for bass management in Direct) -- however, I've noticed that music played in this configuration in my theater room sounds REALLY bad!  Apparently I have more work to do with acoustic treatments...  meanwhile, engaging Dirac via Stereo mode fixes the issue and the tunes sound sweet as honey again.  

Now, my question is this:  if the analog signal coming in from the Gumby is converted back to digital in order to apply the Dirac processing and then converted back to analog on its way out to my amps, then does that mean the resulting sound is more representative of the XMC's DAC than the external DAC?  This distinction is important because, if I continue to prefer using Dirac over non-Dirac for 2ch listening in the theater, then it might not make sense for me to employ an external DAC in that system if its effects will be largely overridden by the XMC's internal DAC.  Not that I'm planning to keep the Gumby in place -- it's going back to my office when the XSP gets back from service -- but it will inform future purchasing decisions.

Well how about trying the XMC-1 by using a digital source (bypass the Gumby) and then see how much difference there is between Dirac switched on versus switched off.

[geebo]

Since the last DAC in the chain is that of the XMC I would think you'd basically be hearing it's DAC. And you are also going through three conversions ( D-A, A-D, and D-A) instead of only one.

[repeetavx]

Yup, only the last DAC counts. As an experiment you should play the same files direct into the XMC-1 and compare them to the files from the Gumby. I think that you'll find that they will sound identical. And that the balanced DAC in the XMC-1 compares well to the Gumby.

[saru]

I've had the house to myself this weekend -- wife is on a business trip -- so of course I took advantage of the opportunity to rock out in the basement for a few hours! I had just gotten a pair of Emotiva's 12 gauge power cords, so I wanted to stick those in the theater amps (XPA-200 on the LR, XPA-5 for the other five channels) and give 'em a test drive. Since Friday (when I put them in), I hadn't noticed much of a change in SQ that could be attributed to the power cord change -- though I wasn't expecting a miracle, so that's okay. However, I did notice that when I switched from Stereo to Direct (again using the Gumby as balanced-in source to the XMC-1), the Direct mode sounded much better than it did earlier this week. Dirac still sounded better, but it was no longer irritating to listen without it. Was the Gumby still in process of finding its equilibrium the first time around? I remember powering it down the Thursday before last in my office and taking it directly downstairs for hookup and power on, then came back to it last Monday for my initial listening session. I thought 3-4 days was sufficient for Gumby, but I guess it does take a full week? I don't think the power cord change would cause the change in performance for Direct mode that I experienced, but I'll try moving the XPA-200 back to its stock cord to verify that.

Thanks for the confirmation that Stereo mode does indeed result in my hearing the internal DAC rather than the Gumby. I will also try removing the Gumby from the chain to see how the XMC DAC sounds in Direct when being fed by the microRendu.