[EliasGwinn]

Quote:

Originally Posted by joijwall /img/forum/go_quote.gif Does all this mean DAC1 understands PCM only, or does it know other digital to analog conversions also? I'm also curious about the different players, both PC based and regular CD-players (at least the ones that plays MP3, I guess a CD is PCM?). Are all players equally perfect when converting WAV, AIFF, AAC, FLAC etc into PCM? That is, will all send the same PCM-bits? Or do I need to choose player carefully? /Joachim

Here is the link to the "Audio Wiki" on our website.

Main Page - Benchmark

That page is filled with all the information you will need about any player.

There are too many variables to tell you that one player is the best. However, iTunes and Foobar lead the pack.

The DAC1 only works with PCM, which includes MP3's, all varieties of Lossless files, WAV, AIFF, etc. It does not include DSD (SACD). However, Dolby Digital, DTS, and ADAT are all encoded versions of PCM, which can be decoded and converted to the DAC1.

Thanks,
Elias

 

[eweitzman]

Quote:

Originally Posted by gjwaudio /img/forum/go_quote.gif Well... maybe, but how are you going to change the volume ? ... Laughable indeed... straight out of Charles Rodriguez... but just in case, I'm off to the Patent Office !

Sorry, Grant, but I beat you to it. 2001 prototype of the two channel version shown below.

I'm considering adapting this to the DAC1PRE. (not)

- Eric

 

[Wavelength]

Eric,

In most cases the dac chips that have both DSD and PCM inputs do not convert DSD to PCM but actually the reverse. The PCM is converted to a bit stream and outputed as a sigma delta dac. Basically the DSD bypasses the conversion and goes directly to the output.

Many of the original SONY SACD's units had jumpers and other things that when cut or switched the DSD information would come out as SPDIF information and some people had recorded the info into their computer and such. I cannot remember what the deal was but I don't think it was as good of quality as the DSD output was.

Most engineers I talked too that did SACD said the contract the the MONEY was hard to swallow. In general this is what killed the idea. The DVD-A stuff just fell by the wayside because people figured the same thing.

It doesn't really matter at this point. If you are in this forum you all ready realize hard formats will be dead soon and there are more and more hirez download sites poping up all the time.

My DSL line went from 5MBS to 10MBPS last week for no extra charge and I hope too look at some of the new sites and download some 24 bit content.

All my buddies who are musicians are asking about master tapes on line and that's when things will get real interesting. The idea of much more dynamic masters is staggering compared to most of the overlly compressed disks you get now.

Anyway.. have fun back to work,
Gordon
Quote:

Originally Posted by eweitzman /img/forum/go_quote.gif Within a playback machine, you might be able to get at the individual data channels after decoding from format XYZ to PCM. Looks like switch-box.com has done that. I read sometime ago that one of the Oppo machines was capable of outputting SACD digital data via the HDMI connection. As it turns out, the DSD data is converted to PCM (24/88 IIRC) and that's what you get. Not DSD, but not reconverted analog either. One of the later HDMI standards (1.3 IIRC) allows protected/DRM data to be passed through the interface with a protection flag. The legal issues with SACD and DVD-A are different. Because they are both encrypted digital data on discs, it is illegal to rip the data from the media in the US. But once the data has been converted to PCM signals inside a properly-licensed and manufactured machine, the data can be transported outside to other devices such as our DAC1s. There's a further issue with SACD in that the technology is licensed from Sony who stipulate (via licensing) that the digital DSD data stream NOT be made available outside the box. DVD-A might have similar licensing issues, I don't know about that. I'm pretty sure you can backup or play the decoded "LPCM" hi-rez streams from "enhanced" DVD-V like DualDisc, DAD, and so on. Copying is still verboten because it's copyrighted material, but not because of the encryption sanctions in the DMCA act. In the case of the Oppo, they must be using one of the DAC chips that accepts DSD data, converts it to PCM, and then converts the PCM to analog. These DAC chips are the basis of the cheap universal players. I think these chips also function as sample rate converters so the PCM version of the DSD data can be grabbed as an output from the DAC chip. That's probably how SACD gets to go down the HDMI pipe in the vanilla Oppo, and also probably what the modifier grabs and sends to the three S/PDIF outputs that he adds to the back of the case. - Eric

 

[sfogg]

Quote:

Originally Posted by eweitzman /img/forum/go_quote.gif In the case of the Oppo, they must be using one of the DAC chips that accepts DSD data, converts it to PCM, and then converts the PCM to analog. These DAC chips are the basis of the cheap universal players. I think these chips also function as sample rate converters so the PCM version of the DSD data can be grabbed as an output from the DAC chip. That's probably how SACD gets to go down the HDMI pipe in the vanilla Oppo, and also probably what the modifier grabs and sends to the three S/PDIF outputs that he adds to the back of the case.

Eric,

The DAC(s) in the Oppo are actually PCM only. The all in one chip (audio decoder, post processing, video processing and even HDMI transmitter) converts DSD to PCM for the Oppo's DACs. The 980 does have the ability to output native DSD over its HDMI interface, or converted PCM, but it can never feed DSD to its DACs natively.

Because of the all in one nature of the decoding chips the limitations of audio over HDMI actually apply to its own DACs as well. Audio on HDMI is carried in the VBI of the video. The video bandwidth effects the available audio bandwidth. 480i/p does not have enough bandwidth to carry 6x96/24 so when you have the Oppo set at 480i/p output and play a DVD-A the DACs are fed at 48kHz. If you switch video output to 720p or 1080i/p then the DACs are fed at 96kHz.

Shawn

 

[sfogg]

Quote:

Originally Posted by furball /img/forum/go_quote.gif DTS/Dolby Digital signals are encrypted. The encryption is there for copyright protection. Because of the encryption, the DTS/Dolby Digital decoder is both a decoder and a multichannel DAC, you cannot separate out the two. The multichannel digital to analog conversion is done at the decoder level, and the decoder only outputs analog outputs. The decoder will not output PCM style digital output for each of the 5 or 7 channels.

There are many DD/DTS decoders that output PCM to separate DACs within the player/pre-pro or pass the PCM on to additional DSPs for post processing then eventually on the DACs. For example the Oppo DV-980H does this.

There are even pre-pros that will output decoded DD/DTS as PCM over multiple SPDIF connections. Theta Casablanca with the digital outputs card option will do this, pretty much any Meridian from the 565 on will do this too to be able to feed Meridian's DSP speakers.

Shawn

 

[ted betley]

Elias: I finally figured out how to engage asio with j river and it works nicely. But I got an Opticis SUB extension cable today and what a fantastic cable it is! Before Opticis I was running a short usb into my dac which in turn was driving about 40 feet of unbalanced interconnect (Guitar Center generic cable). So when I began using the Opticis I could now run a half meter of silver KK (1120 or something) interconnect or a meter of mogami balanced cable. I could not believe it but my KK unbalanced sounds better than the mogami balanced. I had the opposite effect on an scd1. I have only about 25 hours of breakin on the Benchmark balanced analogue outs. Could this still be an issue or should I change my xlr pad down from -20 db to 0 db? Or is it possible that the unbalanced outs of the Benchmark are better than the balanced outs? Either way I could not be happier with my Benchmark usb dac.

 

[gjwaudio]

Hi Ted
Quote:

Originally Posted by ted betley /img/forum/go_quote.gif ...I could not believe it but my KK unbalanced sounds better than the mogami balanced ... Or is it possible that the unbalanced outs of the Benchmark are better than the balanced outs? Either way I could not be happier with my Benchmark usb dac.

You will be surprised at how the sound from the unbalanced connection improves when you take care of RCA sockets (see here).

It is telling that Benchmark have addressed this issue in the DAC1 PRE. Good for all you new buyers. Too bad they dropped the BNCs though - my experience indicates it's a better connection for S/PDIF. (...maybe in the DAC1-PRE Mk2 !).

Cheers
Grant

 

[illkemist]

Quote:

Originally Posted by gjwaudio /img/forum/go_quote.gif Hi Ted You will be surprised at how the sound from the unbalanced connection improves when you take care of RCA sockets (see here). It is telling that Benchmark have addressed this issue in the DAC1 PRE. Good for all you new buyers. Too bad they dropped the BNCs though - my experience indicates it's a better connection for S/PDIF. (...maybe in the DAC1-PRE Mk2 !). Cheers Grant

Hmm...I didn't notice this on the DAC1 USB that I returned. But I just took a look at my Pre, and chuckled. Thanks for the link.

 

[SCOTTY1]

I'm currently trying to decide whether to get a B'mark Pre or a Stello DA220 Mk2 & would be grateful for any input from those that have heard these units.

 

[poo]

Quote:

Originally Posted by SCOTTY1 /img/forum/go_quote.gif I'm currently trying to decide whether to get a B'mark Pre or a Stello DA220 Mk2 & would be grateful for any input from those that have heard these units.

I think the most helpful input I can offer is to read through the previous 150something pages here, then compare that info to the thread on the Stello DA220.

 

[SCOTTY1]

Yeah, I know but I supppose what I can't find is a post along the lines of, "I have lived with B'Mark Pre for x weeks now and my impressions are ......"

 

[EliasGwinn]

Quote:

Originally Posted by ted betley /img/forum/go_quote.gif I could not believe it but my KK unbalanced sounds better than the mogami balanced. I had the opposite effect on an scd1. I have only about 25 hours of breakin on the Benchmark balanced analogue outs. Could this still be an issue or should I change my xlr pad down from -20 db to 0 db? Or is it possible that the unbalanced outs of the Benchmark are better than the balanced outs? Either way I could not be happier with my Benchmark usb dac.

Ted,

The balanced and unbalanced outputs use the same exact same circuitry and have identical performance. The difference you are experiencing may be a result of the differences in output level. With the -20 dB pads, the XLR outputs will be 4.5 dB below that of the RCA outputs. This difference in amplitude will not affect the quality of the sound, but it will affect the perception of quality.

Thanks,
Elias

 

[EliasGwinn]

Quote:

Originally Posted by SCOTTY1 /img/forum/go_quote.gif I'm currently trying to decide whether to get a B'mark Pre or a Stello DA220 Mk2 & would be grateful for any input from those that have heard these units.

If you have any questions that I can answer, don't hesitate to ask.

Thanks,
Elias

 

[poo]

Quote:

Originally Posted by SCOTTY1 /img/forum/go_quote.gif Yeah, I know but I supppose what I can't find is a post along the lines of, "I have lived with B'Mark Pre for x weeks now and my impressions are ......"

In your shoes (and assuming it has all the features you are after), I would buy the Benchmark, and if it doesn't perform as you'd hoped, sell it here in the for sale forum. Nothing like trying it yourself, and you won't lose much reselling it here if you decide to. Surely the ability to try it yourself outweighs the small financial loss you may incur?

 

[illkemist]

Quote:

Originally Posted by SCOTTY1 /img/forum/go_quote.gif Yeah, I know but I supppose what I can't find is a post along the lines of, "I have lived with B'Mark Pre for x weeks now and my impressions are ......"

Well, I've had it for about 5 days. It's too early to draw any conclusions. However, I did have the DAC1 USB for about two prior to upgrading to this unit. So far, I have been very happy. To be honest, aside from features, I can't really tell any difference in performance between the two products. Is there a particular reason why you're looking at the Pre and not the DAC1 USB?