[mr_smidge]

I currently use a Rotel RSP-1098 as my video processor solution, which looks lovely, sounds just lovely, but doesn't have any HDMI connectivity. So instead, I run my two sources (an Oppo DV-983H and an XBox-360) straight to the screen.

But... I now have more HDMI devices to connect. And I've also been considering an iScan Duo to improve the picture quality of my SD sources.

The more sceptical might say I'm trying to justify using a Duo as an HDMI switch .

Question is then, how to set it up with regards to HDMI audio. The Duo has an HDMI audio-only output, which I could connect to an HDMI-endowed av pre-amp. But mine isn't, so I would consider replacing it, either with an Audiolab 8000AP or a second-hand RSP-1069.

Using a Rotel RSP-1069:
+ Inexpensive. Around £400 for a second-hand one, I think.
+ Will match the existing kit and look snazzy.
+ Plenty of old analogue inputs for other kit.
+ Audio management and other features.
- HDMI 1.1 inputs, so wouldn't be able to take DTS Master Audio or TrueHD.

Using an Audiolab 8000AP:
+ Small footprint, which will make some space in my rack for the Duo.
+ Supposed to sound very good musically.
- More expensive at just under a grand.
- Fewer audio managment features.
- HDMI 1.2 inputs, so wouldn't be able to take DTS Master Audio or TrueHD.

I hear that HDMI audio (without video) has significant jitter. However, the Duo's "HDMI audio" output apparently sends a blank 720p video signal with it - hopefully this will mean the clock can be better recovered and hence less jitter (need an expert opinion there!).

I may well run toslink/spdif audio connections to the av pre-amp (either directly or via the Duo) as an alternative if jitter is a worry. But if I'm going to do that, I might as well just not buy a new preamp anyway!


Does anyone have any advice they might offer me?
Rotel RSP-1069 vs. Audiolab 8000AP?
What audio processors do you guys tend to use with video processors?


Thanks!

[Avi]

Originally Posted by mr_smidge

I currently use a Rotel RSP-1098 as my video processor solution, which looks lovely, sounds just lovely, but doesn't have any HDMI connectivity. So instead, I run my two sources (an Oppo DV-983H and an XBox-360) straight to the screen.

But... I now have more HDMI devices to connect. And I've also been considering an iScan Duo to improve the picture quality of my SD sources.

The more sceptical might say I'm trying to justify using a Duo as an HDMI switch .

Question is then, how to set it up with regards to HDMI audio. The Duo has an HDMI audio-only output, which I could connect to an HDMI-endowed av pre-amp. But mine isn't, so I would consider replacing it, either with an Audiolab 8000AP or a second-hand RSP-1069.

Using a Rotel RSP-1069:
+ Inexpensive. Around £400 for a second-hand one, I think.
+ Will match the existing kit and look snazzy.
+ Plenty of old analogue inputs for other kit.
+ Audio management and other features.
- HDMI 1.1 inputs, so wouldn't be able to take DTS Master Audio or TrueHD.

Using an Audiolab 8000AP:
+ Small footprint, which will make some space in my rack for the Duo.
+ Supposed to sound very good musically.
- More expensive at just under a grand.
- Fewer audio managment features.
- HDMI 1.2 inputs, so wouldn't be able to take DTS Master Audio or TrueHD.

I hear that HDMI audio (without video) has significant jitter. However, the Duo's "HDMI audio" output apparently sends a blank 720p video signal with it - hopefully this will mean the clock can be better recovered and hence less jitter (need an expert opinion there!).

I may well run toslink/spdif audio connections to the av pre-amp (either directly or via the Duo) as an alternative if jitter is a worry. But if I'm going to do that, I might as well just not buy a new preamp anyway!


Does anyone have any advice they might offer me?
Rotel RSP-1069 vs. Audiolab 8000AP?
What audio processors do you guys tend to use with video processors?


Thanks!

Is there a specific H/W feature of the Duo that you need ? If not you could consider the DVDO Edge that is same processor in a different case with some connectivity differences. This my save you some money that can go towards an audio processor without any impact on image processing.

I'm not sure there is such a things as audio over HDMI without video. Video bandwidth may limit the type of audio carried but that isn't typically an issue in reality. Audio clock jitter may be more a function of sink audio clock regeneration process per se. This is a much debated subject and I'm not sure there is an accurate answer that has been objectively substantiated.

AVI

[mr_smidge]

Originally Posted by Avi

Is there a specific H/W feature of the Duo that you need ? If not you could consider the DVDO Edge that is same processor in a different case with some connectivity differences.

The Duo has RS232 control, which is high on my must-have feature list. And it's prettier than the Edge .

I could get something like the Oppo 3x1 HDMI switch (with RS232) instead of a video processor, but that still leaves the problem of what to do with all the separate multichannel audio feeds (the 1098 only has five distinct video inputs).

I could justify the Duo by saying that it'll contribute towards the grand plan when I move house and buy a projector .

Audio clock jitter ... is a much debated subject

It is indeed, and my worries are just the product of some fierce debates on other threads on the subject.

Hearing it for myself is what I'd like to do. Just need to find somewhere to demo a Duo around London...


Avi, you're definitely right about the quality of the sink source's audio clock regeneration in avoiding jitter. I'll rephrase the question to be a bit more specific then:

How do the Rotel RSP-1069 and the Audiolab 8000AP compare with audio jitter when taking in an HDMI signal? (Assume the source is an iScan Duo.)

Thanks in advance to anyone who can help,

[mr_smidge]

Originally Posted by Avi

Is there a specific H/W feature of the Duo that you need ? If not you could consider the DVDO Edge

Now that I think about it, this isn't actually a bad idea at all. The Edge has a dedicated IR in on the back of it, which for my purposes is just as good as RS232 - I don't need any two-way communication here.

I think I should be able to find out for myself a bit more about example Edge setups and good audio processors to connect them to.

Cheers,

[Nic Miller]

I was under the impression that the 8000AP could accept DTS-MA and TrueHD - this not correct? Via LPCM that is and not of course bitstream as it cannot decode them.

[mr_smidge]

Hi Nic,

Originally Posted by Nic Miller

I was under the impression that the 8000AP could accept DTS-MA and TrueHD - this not correct? Via LPCM that is and not of course bitstream as it cannot decode them.

If the source can use its own internal processing to decode DTS-MA or TrueHD to good old-fashioned LPCM, then my understanding is that the decoded LPCM audio could happily be transmitted over HDMI 1.1 or 1.2 to the 8000AP (or indeed any 1.x-enabled device).

I don't think there would be any major difference between decoding LPCM and transmitting that, or transmitting bitstream and decoding at the processor. Not unless you count jitter introduced by the signal during transmission, but that's a whole 'nother kettle of fish!

I was just erring on the side of caution in case not all sources could decode to LPCM - is that the case, or is it a requirement that all Blu-ray players must be able to output LPCM? Not sure, as I don't own any BR players .