Originally Posted By: gonk
Yes, when using the CD analog input in bypass mode with front speakers set to "small," you would send a full-range signal to the sub.

The Model 990 uses a 96kHz 24-bit ADC chip, so the audio bit rate and sample rate will be 96kHz/24bit when using the 7.1 analog input. The DAC chip is 192kHz, 24-bit, so that bit rate and sample rate will remain at least 96/24 throughout the 990's digital domain. The 990 may even upsample to 192kHz, although I'm not real sure about that - the specs note that PCM is upsampled, but that could relate only to stereo PCM (received directly via optical or coaxial). Technically, TrueHD supports 192kHz for up to six channels (eight channels is limited to 96kHz), but I don't think anybody's actually used that capability. I know there are a few 96kHz/24-bit Blu-ray discs out there, but most are 48kHz/24-bit. That means the sample rate being used within the 990 will be better than that used originally in most cases, and in a few cases will merely be the same. Certainly not lower. Let your ears give it a try, see what you think. It seems counter-intuitive, but I think you owe it to yourself to give it a whirl before you invest too much time and effort into trying to work around the A/D/A conversion.


First a question: When using the 990's 7.1 RCA analog input and the speaker size set to large, does the 990 still apply the speaker distance that I have set in its menus, or is that not used? I have the speaker distance set in the 990, and have it set to 0ft on the Oppo, so that speaker distance isn't doubled.

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Earlier today I wanted to see if I could hear a difference in the DACs used by the 990 and the Oppo 95.

Had the Oppo RCA's connected to the 990's 7.1 analog. 990's speakers set to large, Oppos speakers set to small and crossover at 60Hz.

Played a CD track I know well a couple times over-and-over that only had a few instruments in it (Baroque) while using the 990's 7.1 input with the Oppo using its DAC. I then changed to the 990's optical input from the Oppo, so the 990's DAC would be used. With the 990 in Stereo mode, the instruments sounded like there was a veil between them and me, also some detail was missing. I then tried the 990 on Upsample, and even through there was more detail, the high-end became too bright for me, almost unnatural. I went back and forth on other tracks and with some other CDs, and each time the instruments and voices (especially solos) sounded more "life like" and "clearer" with the Oppo doing the DAC work while the using the 990's 7.1 input.

Then I decided to try it with the Oppo's speaker size set to large (not using its bass management) and settings the 990's speakers to small, so it would do the A/D/A bass management. So with this, the Oppo is doing D/A with no bass management, sent to the 990's 7.1 input which is taking the Analog and converting it to Digital and then back to Analog so that it can apply bass management. In doing this, there was some loss in detail, similar to using the optical out from the Oppo to the 990 that I tried earlier.

I didn't have time to try a comparison using a BD movie that has Dolby True HD, to see if I could hear a difference between:
1) Oppo speaker size set to small with bass management, 990 7.1 input set to large; with the Oppo doing D/A with bass management and fed straight through the 990 untouched.
-or-
2) Oppo set to large speaker, 990 set to small speaker with bass management; with the Oppo doing D/A and sent to the 900 doing A/D/A with bass management.


Edited by FAUguy (02/19/13 04:11 AM)