[chrisc]

The Multi-channel DAC is used via all other digital inputs other than the USB.

Could you clear up this scenario please?

Using co-ax from a SACD player.  The SACD player is set to only play 5.1 audio and to use only the SACD layer
There is output on L + R rear but I cannot tell if it is "real" rear channel info or something manufactured within the amp?
The info button states: 44.1KHz 2 channel
There is any case rear output when playing USB stereo

Would you know what the answer is?

[Phil A]

SACD players can output DSD via HDMI (version 1.2 or later) only.  If you're using the coax, you're listening to the CD layer of a hybrid disc.  If you have any single layer (SACD only discs) try one of those and you should get no sound via the coax out.

[John Casler]

Could you clear up this scenario please?

Using co-ax from a SACD player.  The SACD player is set to only play 5.1 audio and to use only the SACD layer
There is output on L + R rear but I cannot tell if it is "real" rear channel info or something manufactured within the amp?
The info button states: 44.1KHz 2 channel
There is any case rear output when playing USB stereo

Would you know what the answer is?

Hi Chris,

I have not had the opportunity to use the HD AVP in multi-channel operation, but many of the issues you raise have not come up with the units I have placed.  However, the manual is not a "deep" read of all the features and options.  And since this unit is somewhat unique in its design not all operations are intuitive.

I followed up on our personal conversation and below is some of the response:

<<<<When the source is from USB Audio into the high-end “DAC-10” DAC board USB RCA outputs are fixed at 2V

AVP main L+R output also comes from the DAC-10” DAC but it has to go through the AVP volume control.

Therefore the AVP’s output will be affected by the decoding setup.

When set to Pure Audio mode, then only the main L+R has output. But if it is set to Dolby coding, even if the source is from USB Audio, all the 7.1 outputs have sound from the USB audio.>>>>


Regarding your question above;

I don't think the coax digital out of the SACD player is sending SACD level output.  That is why it is showing 44.1 which is the CD layer.

I tend to think if you have that coax INPUT set for a decoding process, then it will process signals to the other speakers.  If you have it set to.  Check to see what "decoding" that input has assigned.

Below is information from the FAQ's, that might explain when you get 2 channels or multi-channel sound.

<<<<Pure Direct and Pure Audio modes are part of the multi-channel mode and utilize the high quality multi-channel DAC. USB Audio goes through a separate high performance stereo DAC board.

Pure Audio is a 2-channel Stereo mode where multi-channel inputs from the source are converted to 2 channel audio. Pure Direct is a pass-through (from the source device such as BluRay player) mode without any EQ effect.

Don't confuse Pure Audio or Pure Direct with USB Audio input. If you have a computer connected to HD-AVP through USB Audio, by selecting the USB Audio as input source you will be utilising the high-end stereo DAC (this USB Audio DAC has the same performance as NuPrime DAC-10) instead of the multi-channel DAC for surround sound decoding.

The L&R outputs from 7.1 outputs come from USB DAC outputs or AVP outputs. The USB L&R outputs come only from the USB DAC.  That means if you are using USB Audio as the input, there are two sets of outputs: L&R outputs from 7.1 outputs and USB L&R outputs.>>>>

[chrisc]

So what type of signal is output from the rear channel when playing a 2-channel recording via USB?

[chrisc]

SACD players can output DSD via HDMI (version 1.2 or later) only.  If you're using the coax, you're listening to the CD layer of a hybrid disc.  If you have any single layer (SACD only discs) try one of those and you should get no sound via the coax out.

Apparently there is no DSD support via HDMI, so no sound when connecting this way

[rustydoglim]

I might be repeating John's message already.
A frequently asked question about USB audio as the source is what happened to the outputs?
The USB RCA outputs will have fixed 2V max output (i.e. none volume controlled) from the "DAC-10 equivalent" USB DAC board.
The 7.1 outputs have the following behaviour:
1. If the mode set to Pure Audio, then the main L+R have the volume controlled USB DAC output.
2. If the mode is set to any other, then all 7.1 channels will have outputs.

[triumph]

Yes, when using the USB DAC, the USB RCA outputs are controlled by the computer, and the 7.1 outputs are controlled by the AVP's volume.
So, by turning the volume down, there is no output to the centre, rear and sub outputs.  But, I want to use the sub output to help my full range in the low end.  That's where I'm stuck, because to have sub output, it means it will output to the centre and rears as well...

Mode selection is not available when using the USB DAC.

[John Casler]

Yes, when using the USB DAC, the USB RCA outputs are controlled by the computer, and the 7.1 outputs are controlled by the AVP's volume.
So, by turning the volume down, there is no output to the centre, rear and sub outputs.  But, I want to use the sub output to help my full range in the low end.  That's where I'm stuck, because to have sub output, it means it will output to the centre and rears as well...

Mode selection is not available when using the USB DAC.

Hmmmmm. . . wish I had one here to play with, but I don't.

I think it relevant to visualize the design goal of the USB input to the ESS Chipset.  It was to offer an incredibly simple and unfettered path for Audiophile Music.

As soon as you begin adding things like equalization and subwoofer filters, you add circuitry in that path.

You "do" get those features via any of the other digital inputs, but lose the USB (cable) purity.

There may be a simple solution by adding a high quality splitter at the USB RCA outs running the 2nd set to your sub, but this will depend on your sub's ability to accept and low pass to itself via L&R RCA.

Of course this is not the most elegant solution, but would work with some subs that have both Stereo and LFE analog inputs.

Another solution, would be to use an amp like the MCH K-38 (shameless plug) and simply shut down the center and surround channels via the front panel switches when using the USB.  This too is a rather inelegant solution, but would be a rather simple work around.

[chrisc]

I use the RCA outs when playing via a USB input from a computer.  The HD-AVP's volume control works fine and at about -10 delivers a realistic volume on most material.  It is not possible (on JRiver) to adjust the output volume.  Does your model operate differently?

[triumph]

Yes!

Which settings do you use to have the DAC control volume in JRiver?  I have to look that one up. JRiver has so many options... It's easy to get lost my in settings.
So, you are using the two RCA outputs next to the USB DAC port, right?
Not the RCA from the row below....

[chrisc]

...As my Japanese friend says:  "If its not complicated its no good."  But then he is a rocket scientist and also designs electric cars

The stereo power amp for the front speakers is connected to FL and FR at the bottom
The stereo power amp for the rear speakers is connected to LBS and RBS, also at the bottom

Connecting it this way allows me to use the remote volume control on all inputs, HDMI1 and 2, Coax 2, FM tuner and USB.  I assumed when looking at the manual that the RCA next to the USB "B" input was for an analogue signal dedicated to USB and since I did not want that, connected it the way I have described

Now, JRiver:  Under Options, Player and Volume, you can elect, by clicking the word Volume mode, to select Application, Internal, System and Disabled.  I use System and the bar at the top has no effect.  If I choose Internal, then I can adjust the volume with the slider.

Some audio purist on Computer Audio suggested to use the Internal volume would have a degrading effect on the sound quality, which is why I don't use it.

I also use JRemote on an iPad and here there is yet a different way of controlling volume, so if you want to, you can use this option

[triumph]

Ah... so you are using the multichannel DAC, not the better USB DAC derived from the DAC-10.  That's why.

If you connect to the RCA outputs next to the USB DAC input, you loose the ability to control the volume from the AVP.  You can only control from JRiver.

About choosing between Internal and System, here's a blurb taken from JRiver's own Wiki:

Picking Between System Volume and Internal Volume

The determining factor in this decision is the type / quality of your hardware volume.
Sometimes turning up the hardware volume increases the noise you hear if you play silence (use 'Tools > Advanced Tools > Audio Calibration > Silence', and make sure 'Do not play silence' is not checked in Options > Audio). Test this by putting your ear right next to the speaker and adjust the System Volume while silence plays.

If the noise gets louder when you turn up the volume:
Use 'System Volume' so that you don't turn up the System Volume (which we found adds noise above) unless you have to

If the noise is unchanged when you turn up the volume:
Use 'Internal Volume' and leave the System Volume at 100%. This is advantageous because you get a 64bit volume and also because it allows Media Center to have as much signal headroom as possible, which is especially important if you do processing (upsampling, room correction, bass management, etc.)

[rustydoglim]

The rationale is that for people who are using USB DAC's RCA outputs for a second system, it would have a preamp.
Since there are two DACs (DAC-10's USB DAC and AVP multi-channel DAC), implementing two separate volume control would be confusing and costly. Therefore the USB DAC's outputs are fixed.