Jump to content

Sign in to follow this  
a.dent

Oppo to power amp? Advice please.

Recommended Posts

I guess that begs the question at what point is a device in the chain dragging the system down over adding functionality to it?

I plan to sell my Rotel RSP-1570 shortly as I am going fully active, so it will be straight out of the front end into the Ground Sound DCN28 active crossover into multiple amps.

Share this post


Link to post
Share on other sites

Knew I had seen it somewhere.... On the Rotel website http://www.rotel.com/NA/Support/FAQ.htm#q35

"Due to the large bandwidth required to transmit HD audio, the only digital cable with sufficient bandwidth to allow digital streaming of SACD audio is HDMI. However, most HDMI devices will not decode SACD as decoding a DSD signal requires a dedicated circuit solely for the purpose of SACD audio decoding. However, several players that do allow digital streaming of SACD discs will provide an option to convert the digital audio into a more standard PCM digital format, which is a standard digital audio signal that is compatible with most devices."

Quite often there is an analogue track on the SACD as well. I would propose that the audio coming out of any analogue output is not a SACD stream.

Share this post


Link to post
Share on other sites

Knew I had seen it somewhere.... On the Rotel website http://www.rotel.com...ort/FAQ.htm#q35

"Due to the large bandwidth required to transmit HD audio, the only digital cable with sufficient bandwidth to allow digital streaming of SACD audio is HDMI. However, most HDMI devices will not decode SACD as decoding a DSD signal requires a dedicated circuit solely for the purpose of SACD audio decoding. However, several players that do allow digital streaming of SACD discs will provide an option to convert the digital audio into a more standard PCM digital format, which is a standard digital audio signal that is compatible with most devices."

Quite often there is an analogue track on the SACD as well. I would propose that the audio coming out of any analogue output is not a SACD stream.

SACDs store music in DSD format, which is a digital format. Not an analogue one.

The DSD data can be decoded internally via an SACD player's internal DAC or in some machines, can be routed to an external DAC/decoder but the external path is usually NOT an SPDIF connection.

Off the top of my head, DSD data can be sent out via

a. proprietary connections like in Esoteric 2 box (or more) transport + DAC devices, or dCS multi box solutions (proprietary based on FW connector but not compatible with regular FW) or EMM Labs multi box solutions (variation of fibre optic)

b. a FireWire connection used in earlier Pioneer and Sony SACD players and often partnered with their corresponding AV receivers. Sometimes called i.Link

c. DenonLink (1-4) uses a regular shielded Cat5E cable

d. DenonLink HD from some 2012 models onwards via a coax cable (but not SPDIF)

e. HDMI

Share this post


Link to post
Share on other sites

SACDs store music in DSD format, which is a digital format. Not an analogue one.

No I wasn't suggesting that DSD was analogue, only that there is often a second analogue track (stored digitally) on the SACD disk for those wanting to buy SACD, but only having a CD player to play it on. I would strongly suspect that it is PCM track which is put through the DAC and transmitted as an analogue signal. The only other way would be for it to do a DSD to PCM to analogue conversion.

The problem that I face is that I can't get a true DSD signal direct to my active cross over, as the only digital inputs it has are Coaxial S/PDIF, balanced AES/EBU, and two optical Toslink.

So even if your playing a SACD if it has to go through the internal DAC and it's only going to be CD quality by the time it exits the Oppo.

To make matters worse it then has to go through the ADC before being manipulated in the digital domain and back through another Burr Brown DAC, it would have been nice to do a straight DSD input to avoid the DAC to ADC conversion and maintain the higher bit rate as long as possible.

post-132474-0-90799800-1339662149_thumb.

Share this post


Link to post
Share on other sites


No I wasn't suggesting that DSD was analogue, only that there is often a second analogue track (stored digitally) on the SACD disk for those wanting to buy SACD, but only having a CD player to play it on. I would strongly suspect that it is PCM track which is put through the DAC and transmitted as an analogue signal. The only other way would be for it to do a DSD to PCM to analogue conversion.

The problem that I face is that I can't get a true DSD signal direct to my active cross over, as the only digital inputs it has are Coaxial S/PDIF, balanced AES/EBU, and two optical Toslink.

So even if your playing a SACD if it has to go through the internal DAC and it's only going to be CD quality by the time it exits the Oppo.

To make matters worse it then has to go through the ADC before being manipulated in the digital domain and back through another Burr Brown DAC, it would have been nice to do a straight DSD input to avoid the DAC to ADC conversion and maintain the higher bit rate as long as possible.

What you are referring to is the CD/RedBook layer in Hybrid SACDs. These are STILL a DIGITAL format. Not ANALOG.

Most SACD players will not output DSD over SPDIF, so the only way you can get a signal out from those players is to read the CD layer instead.

But if you play the SACD layer, the SACD player's DAC will be fed from the DSD layer. Now not all SACD players have a DSD DAC. Some (and oddly enough even in some expensive players like one from Soulution and even Esoterics from a few gens back) had a PCM only DAC so the DSD was converted to High Res PCM (> RB) and then fed to the DAC. But you should be getting the DSD layer and not the RB layer.

ps one interesting feature I found from my EMM Labs XDS1 SACD player. I found that it's SPDIF output (AES/optical) would send DSD as 24/88.2 so that might work for your active DSP crossover system.

Another option is to use say an Oppo Universal player and send DSD out as PCM over HDMI. Then feed the HDMI to a splitter that sends audio out over SPDIF (usually optical on the units I saw) and video over HDMI. The one I bought was from Amazon UK called Atlona but it seems to have been discontinued.

Share this post


Link to post
Share on other sites

I tried a bit of an experiment last night to see if I could get the RSP-1570 to receive the signal as DSD but alas it doesn't support. Found this earlier tonight...

"Made-in-Rotel's manufacturing plant in China, the RSP-1570 has most features any videophile would want, including 1080P video, 7.1 decoding for all home cinema audio formats (Dolby Tru HD, DTS Master), as well as straight ahead uncompressed PCM. Two-channel hi-fi buffs get analog bypass of the internal processing and video circuitry for a straight analog signal path.

The RSP-1570 will also pass DVD-Audio format soundtracks up to 24-bit, 192 kHz via the HDMI jack, but you have to have one of the rare DVD-A players with HDMI output. Unlike the Integra processors, the RSP-1570 does not relay DSD digital signals via the HDMI input. SACD is decoded via the player and connected to the preamp analog inputs.

The Rotel processor/preamp is programmed with numerous DSP modes to enhance surround, normal stereo and mono soundtracks. Digital SPDIF inputs allows PCM audio to feed the preamp for 24-bit stereo audio up to 96 kHz. The HDMI input also accepts these digital signals, as well as the previously mentioned surround formats.

The Faroudja video engine offers excellent upconversion of DVD video to near HD quality, as well as decoding of true Hi-Def sources up to 1080P. The video processor supports Deep Color as well as 1080P-24 frame video via the HDMI v1.3."

Which is consistent with what I found, I could only get the Oppo to show SACD PCM on the screen. I had various leads connected (2 channel analogue, digital coax and HDMI) but it really didn't make much difference what I used I essentially had two options. 2 channel analogue or HDMI, it was completely ignoring the 75ohm digital coax cable I had connected.

From within the Rotel it didn't matter what input type I chose it played through the analogue leads. The only time I could get anything but analogue was when I selected HDMI and then it lit up the 88.2 on the display panel. Theoretically the sound through the HDMI should have been far superior to the analogue but when bypass is selected on analogue it leave the HDMI for dead.

Share this post


Link to post
Share on other sites

Truth is most AVRs don't have a great DAC implementation. Plus HDMI has a very high jitter issue. HDMI 1.3 did offer a way around the jitter issue called ARC which is a form of clock control. Not to be confused with ARC in HDMI 1.4 which stands for Audio Return Channel.

ARC - Audio Rate Control was also branded as PQLS by Pioneer and HATS by Sony worked to create something akin to master/slave clocks between the player and the AVR.

I don't have experience with Sony or Pioneer's implementation. But Denon has something similar called DenonLink which IMHO brings a noticeable improvement for SACD and DVDA (DL3) and BD Audio (DL4).

Share this post


Link to post
Share on other sites

I am semi convinced that HDMI is a white elephant… In no other technology before it have I experience so many issue with loosing video sync and general misbehaviour.

While HDMI is conceptually a good idea for those not wanting to have cables run everywhere, I am still not convinced that video and audio should be run in the same cable.

With each iteration of HDMI they are solving more and more problems, but I don’t see it as the great white hope it was billed as…

Share this post


Link to post
Share on other sites


First gen HDMI wasn't great but with firmware updates, even my old Onkyo 875 from I dunno, 5 years ago was quite stable at the end. I haven't had any issue with my last AVR update from 3?years ago and my projectors from a year ago.

The main issues with HDMI relate IMHO to cable length. I have a NuForce 15m and a Wireworld 12m which were rated up to High Speed at those lengths and thankfully have worked without a glitch.

Share this post


Link to post
Share on other sites

I don't think the issue should be in the interconnects as I use IXOS XHT658-100 for every HDMI cable in the system, I think the issue is in the handshaking and communication between the devices. I think possibly the satandards are not being implimented well enough to ensure effective communication.

Share this post


Link to post
Share on other sites

I might weigh in a bit. I've got the oppo 95.

It can stream DSD over HDMI, or resample DSD to PCM and output over HDMI.

Whilst I have not tried it the PCM over HDMI should be able to be captured out with an audio break out box, goto Jaycar or eBay for one ~ $70 or so.

When using digital out / DSD to PCM, I believe the oppo internal converter changes to use PCM as well.

Unfortunately, I have heard a significant degredation in sound quality when using PCM rather than DSD stream. I have tried a few sample rates namely 192kHz and 176kHz but the sound is just not the same. Not bad, but less focused.

I haven't tried the sound of DSD over HDMI, but I have a high end Pioneer receiver, that could decode it. I might give that a try over the next few weeks.

Greg

Share this post


Link to post
Share on other sites

I tried a bit of an experiment last night to see if I could get the RSP-1570 to receive the signal as DSD but alas it doesn't support. .... I could only get the Oppo to show SACD PCM on the screen. I had various leads connected (2 channel analogue, digital coax and HDMI) but it really didn't make much difference what I used I essentially had two options. 2 channel analogue or HDMI, it was completely ignoring the 75ohm digital coax cable I had connected....

Assuming I understand what you are saying correctly....

You won't get a coax cable to carry a DSD stream --- the player and the receiver won't support it because of the lack of DRM security on SPDIF (coax or optical). Ditto AES/EBU.

You'll only get HDMI cable to carry a DSD stream if the receiver has the necessary decoder --- which should be stated in the receiver's documentation.

And, of course, an analogue cable (connecting analogue ports) will only carry an analogue signal, so any DSD stream must be converted to analogue in the player. This will bring the receiver's analogue input preamps into play, which is sometimes their weakest link, although it should be quite good in the Rotel (famous last words).

You also said here that "if your playing a SACD if it has to go through the internal DAC and it's only going to be CD quality". That’s not quite true. If it was, then everything would always be CD quality because it has to go through a DAC somewhere on its way to the speakers……..

cheers

Share this post


Link to post
Share on other sites


Assuming I understand what you are saying correctly....

You won't get a coax cable to carry a DSD stream --- the player and the receiver won't support it because of the lack of DRM security on SPDIF (coax or optical). Ditto AES/EBU.

You'll only get HDMI cable to carry a DSD stream if the receiver has the necessary decoder --- which should be stated in the receiver's documentation.

Correct...

And, of course, an analogue cable (connecting analogue ports) will only carry an analogue signal, so any DSD stream must be converted to analogue in the player. This will bring the receiver's analogue input preamps into play, which is sometimes their weakest link, although it should be quite good in the Rotel (famous last words).

Pre amps yes...

If you use the bypass feature and then it receives and outputs the raw Oppo analogue signal without any modification.

The DAC in the Oppo BDP83SE is marginally superior to the DAC in the Rotel.

You also said here that "if your playing a SACD if it has to go through the internal DAC and it's only going to be CD quality". That’s not quite true. If it was, then everything would always be CD quality because it has to go through a DAC somewhere on its way to the speakers……..

cheers

Perhaps I shouldn't have said the conversion through the DAC but rather the DSD to PCM conversion.

Starting to twig as to why I am getting better sound from the analogue feed than the HDMI... Because the Rotel doesn't support DSD it is doing a DSD to PCM conversion within the Oppo and then it is running through the Oppo analogue Stereo DAC which is then bypassed in the Rotel, whereas using HDMI the conversion from DSD to PCM is still taking place but it is converted at the Rotel as there is no bypass mode on HDMI.

Analog Audio Hardware:

Stereo Digital-to-Analog Converter (DAC):

ESS Technology ES9016



4 DACs per channel

7.1ch DAC:

ESS Technology ES9006

Greg perhaps we can do a bit of experimenting with this next weekend?

Edited by Silent Screamer

Share this post


Link to post
Share on other sites
....using HDMI the conversion from DSD to PCM is still taking place but it is converted at the Rotel....

There should be an SACD output option in the Oppo's setup menu, where you can select PCM or DSD. Select PCM and the conversion will be in the Oppo, just like when using the oppo's analog outputs.

cheers

Share this post


Link to post
Share on other sites

Hi Arg, yes the DSD to PCM conversion is taking place at the Oppo. I probably should have chosen my words a little better. I should have said the DAC conversion is taking place at the Rotel when using digital / HDMI, whereas analogue is taking place at the Oppo and the Rotel DAC bypassed.

If the Rotel had DSD capability it would be intersting to see what it sounded like then...

I probably should have researched the Rotel a bit better before purchasing it... but then again I didn't buy the Oppo until after I bought the Rotel and none of my other CD /DVD players support DSD.

Edited by Silent Screamer

Share this post


Link to post
Share on other sites

ss for sacd and dsd I'm not sure your going to be doing much better than using the oppos analog outputs. the real benefit of the oppo is its analog output as well. so sort of leaves me wondering why going through all this trouble ? if just planning on using hdmi only maybe worth selling off both the 95 and the rotel and buying cheaper 93 and putting cash towards a more suitable pre ? anyways just a thought :)

Share this post


Link to post
Share on other sites


al I've been in contact with the manufacturer of the DCN28 active cross over I plan to add to the equation, and he recommends using the coax digital out over analogue. The reasoning behind this is if I use analogue it has to be put through a ADC at the X-over to be manipulated in the digital domain and then run through the DAC in the X-over. The Rotel is coming out of the game and going on the bench when I go active. Just thinking though If I use the digital out I won't be able to tap off it for the other speakers once it goes into the DCN28, so I might have to use analogue anyway to get full 5 or 7 channels... Time for pen and paper I think.

Share this post


Link to post
Share on other sites

Interesting discussion - I'm using an Oppo 83SE, but now feeding it via HDMI into a NAD M51 DAC. I've got the Oppo outputting SACD via PCM (the NAD doesn't support DSD). It outputs a 48kHz PCM stream which is converted from the DSD layer, I've tried it with super SACD's that don't carry a redbook layer just to reassure myself.

How does it sound? pretty good actually, better than either SACD or CD sounded via the analogue outputs through the same power amp and speakers. I just wish NAD would have built in DSD support, however I'm not sure the difference it would make. - AJ

Share this post


Link to post
Share on other sites

Possibly the DAC in your NAD is better than the DAC in my Rotel. I am somewhat disappointed with the Oppo HDMI output / Rotel combination. Unless I have missed something obvious, the analogue out seems a better option for me (in two channel).

I have been listening to my Oppo BDP83SE straight into the Rotel RB1092 amp and then the Cremonas. While I need to make sure I have the Oppo set on the lowest notch (5) when I play different types of music (as 5 on some music is nearly too loud) I find the music quality is superior to running it through the Rotel.

But the catch with the 83SE is it uses different DACs for the stereo and the multichannel out, so I probably wouldn't run this combination for surround sound. If I was running a BDP95 where the DACs are the same on both I might.

This has been an interesting thread because I have discovered there is no one right way, it seems to depend very much what you have mated to what.

Share this post


Link to post
Share on other sites

I previously had a denon universal player, and the only way I could listen to the dsd track of an sacd disc was to use the analogue outs from the player to the analogue ins on my Nad t762 receiver.

Am now using an Oppo BDP 95AU universal player with a NAD T775HD receiver and can get the full benefit of the DSD quality via both HDMI and analogue out. Benefit with still using the analogue out is, once I have started the disc playing, I can turn off the TV without losing the sound, whereas through the hdmi handshaking, the sound stops when playing through hdmi and turning the tv off. Unless you do not turn on the tv in the first place, and just press the play button (or ok button) on the Oppo after giving it time to read the disc.

Have also connected a WD Elements Play to the usb port on the back of the oppo, which allows me to play multi-channel hires (96k24bit) flac files ripped from dvd-A discs. These can be played via hdmi or analogue out.

By the way, dvd-a discs would also only play through analogue on my old Denon to NAD T762, but will now play through the hdmi connection from Oppo to NAD T775HD av receiver.

The NAD display confirms it is playing the full 24bit 96k sound.

I should mention that my old Denon/NAD T762 system did not have hdmi, either from the Denon or on the NAD 762: only digital choices were co-ax or optical

Edited by audiomad

Share this post


Link to post
Share on other sites

I can confirm that using the analogue outputs of the Oppo 95 through to a 5 channel Rotel power amp works well. It takes a little work to get the standard volume levels to what I liked but that is about all.

There is an advantage to using something like the Marantz AV 7005 preamp and that is the flexibility of adjustment of individual channels and the ability to accept inputs from HDMI and the digital inputs (ie Squeezebox Touch). Other features of an AV preamp can be convenient as well. That is why I use a preamp as well as several power amps (having a subwoofer fetish as well :)

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...