TV optical out quality?

[quattroll]

I want to get some opinions on going with my TV's optical out to a XDA-2/UPA-2 vs HDMI to a Marantz NR 1504. Now the power of course is a big difference, but at normal levels there doesn't seem to be much difference. Could it be that the receiver gets a "better" signal? i.e. its processor is more capable of down mixing and converting that the dedicated dac working with the already down mixed signal. I have used both, but most recently had the receiver going because I wanted to use the crossover functions. BTW no trigger on the Marantz for the UPA-2, which is a bummer.

Maybe I am splitting hairs here, but it is so hard to A/B these things. Maybe when I test I should have the spl meter to help?

Thanks

[KeithL]

1) You're comparing very different operating conditions. Since the XDA-2 is a 2-channel DAC, you must have your TV configured to down-mix the signal to two-channel (when it's a surround sound signal). The exact result you get when doing so may be quite different than what you get when sending a surround sound signal to the receiver, and allowing the receiver to down-mix it. The decoder and downmix in the TV may be quite different than those in the receiver.

2) If you're trying to evaluate anything related to sound quality, using an SPL meter to measure the sound level in the room is a remarkably inaccurate and indirect way of doing so. When you're trying to take in-room response measurements of speakers, using a meter and a microphone is the best way to do so - because it's the only way to do so. However, when measuring anything about electronic signals, and the signals themselves are available to be measured, virtually ANY other measurement method is going to give you more accurate and more repeatable results.

Feb 27, 2018 14:49:57 GMT -5 quattroll said:

I want to get some opinions on going with my TV's optical out to a XDA-2/UPA-2 vs HDMI to a Marantz NR 1504. Now the power of course is a big difference, but at normal levels there doesn't seem to be much difference. Could it be that the receiver gets a "better" signal? i.e. its processor is more capable of down mixing and converting that the dedicated dac working with the already down mixed signal. I have used both, but most recently had the receiver going because I wanted to use the crossover functions. BTW no trigger on the Marantz for the UPA-2, which is a bummer.

Maybe I am splitting hairs here, but it is so hard to A/B these things. Maybe when I test I should have the spl meter to help?

Thanks

[quattroll]

Thanks Keith, understood. Maybe I should look for a umc-200, and get crossover and trigger capability. Not ready to spring for MC-700!