Recording DSD, playing back over PWT


#1

Just a quick note to repport some of what we’ve been up to lately.



Using the NPC to process vinyl LP’s, in both PCM and DSD, we’ve been playing around a lot with what we can and cannot do. For example,would it be possible to record DSD out of the NPC, record it onto a DSD and play it back via the PWT? The answer, it turns out, is yes, but not without some experimenting.



We first took the USB output of the NPC and plugged it directly into my Mac computer. This was pretty simple, as described in the NPC Owner’s Manual. Using the Audio Midi panel of the Mac, I set the PCM sample rate where I want (in this case 96kHz/24) and record whatever I wish using Audacity. This works great but it’s not the easiest program to use (more on that later).



If I switch the NPC over to DSD, I can again go back to the Mac’s Audio Midi panel to select either single or double DSD. For some reason, on my Mac, I have to unplug the USB cable from the computer and plug it back in when I switch to DSD. Then the two sample rate choices appear. Hmmmm, weird. Choosing standard rate (176.4kHz/24), I can hear a small amount of white noise coming through the speakers. This is normal as there’s really no way to monitor DSD in the computer I know of.



I then take Audacity and set the sample rate of that program to 176.4kHz and try recording a minute’s worth of DSD playing through the NPC. Because we use DoP, which mimics PCM, I tell Audacity to save it as a WAV file, but have to go to some trouble to force Audacity to be 176.4kHz/24 bit. It only wants to do 16 bit. When we go to play this back to see what happens, we get mostly noise but some music. Turns out Audacity is lopping off 8 bits an di indeed only doing 16 bits.



We then switched over to Vinyl Studio. Quite a bit nicer program than Audacity. And if we set it up to record at 176.4kHz/24 bit WAV files, it does it just fine. If we then take the resulting WAV file that Vinyl Studio generates, burn it onto a DVD as a WAV file, then we can play it in the PWT just fine. The PWT will output the DSD file and if you have a DAC that handles DSD, you get wonderful music out. :slight_smile:



We can’t, of course, do double DSD as that’s running at 352.8kHz/24 and that’s a format you can’t transfer over coax or AES/EBU. We can send it over I2S and USB, but that’s pretty limited in what can then play it back.



That’s about it for a moment. We’re still playing. If you have any experience with this, jump into the forum and let us know. So far, Vinyl Studio is the only program we know that works well with DSD - although it doesn’t natively support it or even recognize that it’s recording that format - so it takes a little faith that it’s working.



This really is a new frontier we’re charting here.


#2

Very cool, Paul!



Audacity will accept up to 32-bit streams for recording, but truncates everything to 16 bits. This is why I recommended Goldwave as a quality, inexpensive program. Unfortunately, it is PC only (It will run on Linux with Wine). I expect it would have no trouble with DoP as it handles up to 192/24.



Paul McGowan said: This is normal as there’s really no way to monitor DSD in the computer I know of.


Yes - there is no way to monitor DSD without a significant investment in specialized in hardware and software.

#3

This link shows you what devices support DSD / DoP through the various digital inputs including SPDIF.



www.dsd.sonore.us



Jesus R


#4

Very impressive database.



Thank you!


#5

Paul, what if we already have DoP files? I have many (not all) of my SACDS ripped using my very precious PS3.


#6

Tony, I don’t understand your question. Are you asking what’s going to play those files?



I can give you all a piece of exciting news, Paul, the author of Vinyl Studio in the UK, is working hard on the software to include DSD and he’s already gotten the monitoring problem fixed. What he’s doing is converting the DSD to PCM (for monitoring purposes only) and keeping the DSD stream perfectly intact. What that allows you to do is monitor the recording, cut it into tracks, yet have no problems with DSD files at all.



It’ll be very cool and Paul and I are working together on this.


#7

I have an old Sony PS3 that I use to pull the SACD info off my SACDs. I have them on my PC already as DoP files. So if I start with these, what steps would I take to be able to play some form of them through the PWT?


#8

Simply rename the file as a .WAV file and it should work fine.


#9

And I assume burn them to DVD-R disks? But how? As plain old “files”? Sounds too simple.


#10

If Paul is correct that you can just rename the files as .wav files, then you would follow the procedures for burning WAV files to DVD-R which is detailed in the Knowledge Base. Just access the page: http://www.psaudio.com/learn/faq6/, and then select the first item in the PerfectWave Transport section titled: “How To Burn DVD Discs for PWT Playback Using IMGBurn”.


#11

Thanks Bill. I plan to give this a try.


#12

Wow! You guys are far, far beyond my league. Completely lost.


#13

I can give you all a piece of exciting news, Paul, the author of Vinyl Studio in the UK, is working hard on the software to include DSD and he's already gotten the monitoring problem fixed. What he's doing is converting the DSD to PCM (for monitoring purposes only) and keeping the DSD stream perfectly intact. What that allows you to do is monitor the recording, cut it into tracks, yet have no problems with DSD files at all.


That is excellent news, please keep us informed on the progress!


#14

As long as the files are DoP (DSD over PCM) then they are, actually, WAV files as far as the PWT is concerned. It really never does any decoding, just passing the digital information on like a good little soldier. So simply rename the file extension to .WAV then burn onto a DVD as you would normally.



On the Mac it’s easy (isn’t everything?), just drag the renamed files onto the DVD in finder and burn the disc.



We are working on seeing if we can’t do an update to the PWT to make it even easier, but with the help we’re getting from Vinyl Studio, this should perhaps not even be necessary.


#15

There is nothing tricky about the process on any platform.



First, the files must be wav files. Nothing else will work.



Then, simply burn them to a DVD as a data disc using any authoring software which supports the UDF 2.0 file system.



By coincidence, Macs burn DVDs to this as a default. PCs, as usual, provide for many more options. Thus, one needs to make sure you are burning with the file system the PWT expects.


#16
We are working on seeing if we can't do an update to the PWT to make it even easier, but with the help we're getting from Vinyl Studio, this should perhaps not even be necessary.


My vote goes for updating the PWT if it's possible. Let's not establish too many dependencies on outside sources. If one of them decides to go bye-bye we lose a promising capability, or at least it gets harder to do.

Then, simply burn them to a DVD as a data disc using any authoring software which supports the UDF 2.0 file system.


Simple. Thanks!

#17

I know I am showing my ignorance. Paul says you can rename a DOP file to wave, put on a disc and play in pwt over the DSD player. I have some DSF files and have looked all over the internet and can’t figure out how to convert to DOP. I can play DSF and have software convert on the fly as it is playing. I can convert to FLAC over DOP. I can convert to FLAC. But I don’t see a program to convert to DOP and keep it on my hard disc.


#18

I think the guys here use FOOBAR to convert to DOP.


#19

Using foobar2000 isn’t for the faint of heart: http://www.audiocircle.com/index.php?topic=119364.0

Be sure to use a separate (portable) foobar2000 installation since the SACD reader they use isn’t compatible with the your normal foobar2000 installation.


#20

Having issues with these DoP DVDs stuttering/skipping when playing on the PWT. I have used foobar to convert the DSD files to DoPs and have burned them to a DVD using ImgBurn. My 24-96 PCM DVDs that I have burned in the same way do not skip/stutter. I’m wondering if it is an issue where I need to burn the higher rez DoP DVDs at a lower write speed? I currently use 4x as a write speed.