Originally Posted by kdp99
Can you use THX Ultra II to create a surround back channel from a 5.1 source with the digital multi-channel inputs as you can with a normal optical input ?
First of all, we need to point out that the coaxial inputs are equal with the optical ones, since they are both digital.
But using of the multi-channel digital input is a new concept and a new domain in this series of the Denons.
As it is mentioned above (perhaps not so clearly), this input consists of 4 coaxial jacks, that have to work simultaneously
, with No. 1 input ALWAYS
active. If No. 1 input is not active, the MultiCh input simply does not work. Also, all four (or perhaps the three) of them must be fed by a multi-channel digital signal, coming from the same source and controlled by the same Master Clock.
The main reason that the user needs to utilize this input is the use of an already decoded Hi-Resolution (HD) digital signal in an LPCM form, as this can come out from an HD player (Blu-Ray or HD-DVD) HDMI output.
In order to get this signal from an HD player - other than its HDMI output - you need a special converter box (unit), which "transforms" the HD digital signal from its HDMI route to a 4 stereo coaxial one. By this way, you can feed the 4 jacks of the Denon with a full HD 7.1 digital signal, devided into 4 stereo ones as:
- No. 1 jack -> Front Left + Right
- No. 2 jack -> Front Center + Subwoofer
- No. 3 jack -> Surround Left + Right
- No. 4 jack -> Back Surround Left + Right (if existing in the disc material).
I would not send this HD (Hi-Resolution) digital signal to the MultiCh input, even if this is not a 7.1, but a 5.1 one, to down-convert it into a Dolby Prologic 7.1 one, simply because this way the signal may be compressed and therefore it may loose its HD characteristics.
For any other user, who might be interested, I have ordered such a unit to Shawn of www.switch-box.com
, after experimenting with my A1SE, in order to determine which digital input is for which channels.
This unit is called CLUX and it is something like this:http://www.switch-box.com/S_PDIF_ins...CLUX-11SA.html
or better like this:http://softronix.com/pictures/clux/IMG_2977_SMALL.JPG
In order to be sure what I had to order, I did the following experiment:
Since I was suspecting that the coaxial inputs 2,3 and 4 remained inactive, even if the user has chosen to activate the MultiCh Digital In, if there is no signal at input No. 1, I did the following connections:
- I took a well known Y-Adapter (One RCA Male-Two RCA females), same like the Radio Shack Gold-Plated Audio Y-Adapter (http://www.radioshack.com/product/in...ductId=2103638
) and I plugged it in Input No. 1.
- Then I connected a coaxial digital cable from my DVD coaxial SPDIF output to the one female end of the Y-Adapter, thus feeding the Input No. 1 with a PCM stereo digital signal.
- Then, I connected another coaxial cable to the other female end of the Y-Adapter and from there to No. 2 Input of the amplifier.
- I played a Test DVD, providing White Noise, Pink Noise and sine signal of various frequencies. By this, I could feed both inputs together with a PCM signal, keeping No. 1 Input active. I repeated this test, by changing the second cable from No. 2 Input to No. 3 and to No. 4.
- During these changings I tried to listen to my speakers, to see from which channels the sound was coming out.
- The test revealed that if No. 1 input is active, then the input signals correspond to the following channels:
No. 1 Input: L+R Front
No. 2 Input: Center Front + Subwoofer
No. 3 Input: L+R Surround
No. 4 Input: L+R Surround Back (or Effect, as it is marked on the amplifier)
The following preconditions are necessary:
1) The signals must be LPCM, up to 192 kHz -24bit
2) No. 1 Input must always be active
3) MultiCh Digital In has to be activated from the amplifier menu (see above).
4) All four stereo digital SPDIF signals must be controlled by the same Master Clock, i.e. from the same digital source.
By this, any source that can give the user a MultiCh Digital signal, can be connected to this input and allow the amplifier to handle and process the signals, as one source and as it does with the other common digital signals (DD, DTS, MPEG etc.)
After this test, and of course after consulting swith-box.com once more, I ordered the CLUX. Unfortunately, I am not able to test it with my A1SE right now because I am abroad, until the beginning of April, when I expect to return home.
Till then, I only have to wait.