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Author Topic: DSD to PCM question...thanks.  (Read 5411 times)

gazjam

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DSD to PCM question...thanks.
« on: December 06, 2015, 06:33:40 am »

I have bunch of Dsf and Dff files which I want to convert to PCM.
Looking to check if this is good way to do it, and have a couple of questions....thanks. :)

My preference is to have Weiss Saracon handle the sample rate conversion down to, say, 24/176 or 88, but Saracon only accepts Dff files, not Dsf as input so need another way to convert these files...
Tried Foobar but found it very slow and have a lot of them to do and not a lot of time!

Thinking to use JRiver library tools/Convert Format to extract the Dsf files as Uncompressed Wav, then convert to playable PCM.
A good way to do it?

Two questions on this method though...

1) As Sacd is mastered -6db compared to PCM, will converting to Uncompressed Flac in JRiver affect this or will I add 6db in e next conversion step?
2) Sacd to PCM conversion usually involves some element of Noise Shaping, 30Khz filters etc,  which (I'm assuming) is not done in the conversion to Wav?

Any suggestions on this? Any way to do it post conversion to Wav in JRiver?
I know JRiver plays these files natively, but my server is a bit underpowered and doesn't really cope with on the fly conversions.

Thank you. :)
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dtc

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Re: DSD to PCM question...thanks.
« Reply #1 on: December 06, 2015, 08:09:35 am »

MC applies a filter for high frequency noise. As of MC 20, the default is 24 KHz@48dB/octave. You can turn the filter off or choose from options at 30KHz@24dB/octave and 50 KHz@24dB/octave. The default filter is at a relatively low frequency and the other two are too weak to take out all the noise. There was some talk of changing these filters in MC 21, but I do not have that loaded so am not sure if the changes were made. The filters are set in Tools - Options - Audio - Advanced - Configure Input Plug-ins - DSD. You can also set you own filter in the conversion process in DSP Studio for conversions - Parametric Equalizer.

When converting, there is an option to add 6 dB when doing the conversion.

You can convert directly to wav or flac.
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gazjam

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Re: DSD to PCM question...thanks.
« Reply #2 on: December 06, 2015, 08:45:27 am »

Cool,
thanks for the reply.

Great to know both the noise shaping and the 6db gain are both do-able in JRiver.

Final question?
Regarding Dither, its my (mis?)understanding that this is only needed if your stepping down the bit-depth to, say, 16bit from a 24bit original for burning to CD for example..
If I'm keeping my 24bit DSD files as 24bit PCM, assuming I don't need to apply dither?

Just checking before I undergo a bit batch convert, thanks. :)


Thanks.
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blgentry

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Re: DSD to PCM question...thanks.
« Reply #3 on: December 06, 2015, 09:16:32 am »

Just a few points of clarity:

WAV stores PCM data.  So converting to WAV *is* converting to PCM.  There's no need to do it again with another tool.  The job is already done!

DSD is a "one bit" format.  There's no such thing as "24 bit DSD".  All DSD is single bit.  As I understand it, you would normally apply dither with any conversion from DSD to PCM.  Except for *maybe* converting to 352kHz, as 352 is the equivalent PCM rate of single rate (2.8MHz) DSD.

Brian.
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gazjam

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Re: DSD to PCM question...thanks.
« Reply #4 on: December 06, 2015, 03:05:14 pm »

Thanks again.

Have the workflow worked out...

DFF files converted to 24/176 Flacs in Saracon, +6DB gain with TPDF dither applied. Saracon applies its own low pass filter automatically.

DSF files into JRiver:
Input plugin configured - Permissive (50Hz@24db/octave) set, Dither disabled...extracted as 24/352 uncompressed WAV.
WAVs imported into Saracon, +6db gain, TPDF dither applied, and converted to 24/176 Flac.

*Did a few sound comparisons and the 2 step DSF procedure produced a better final result to me. Different Algorhythm maybe, that plays nicer with my Dac, dunno...
Tried different Low pass filters too, and the Permissive one seems to retain the life in the treble a bit better.

Spent a bit of time fussing over different options, have what works best for me now. :)

Now just to crunch through my SACDs!
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dtc

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Re: DSD to PCM question...thanks.
« Reply #5 on: December 06, 2015, 03:42:14 pm »

I presume Saracon has a frequency display option.. You might want to look at the high frequency noise in the converted signal. My experience is that the 50 KHz@24dB/octave filter leaves too much high frequency noise. I ended up using a 60 KHz@48dB/octave filter to get rid of the high frequency noise.

If I remember correctly,  the Saracon filter is like the default MC one - step at 24KHz or so - or it used to be.
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gazjam

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Re: DSD to PCM question...thanks.
« Reply #6 on: December 08, 2015, 09:01:14 am »

Actually, I'm having a rethink out low pass filtering when going from DSD to PCM...

My Dac has a built in low pass filter so thinking I don't need to apply one in software?
Cant seem to find any option to disable the filter in Saracon, and its on by default, so might extract to uncompressed WAV in JRiver with NO filter applied, (and assume minimum quality loss) then use Saracon just to do 24/352 PCM to 24/176.

Frustrating trying To come up with "best practice" here as I don't want to compromise if mean help it. :)


Thanks guys.
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dtc

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Re: DSD to PCM question...thanks.
« Reply #7 on: December 08, 2015, 09:31:27 am »

You can set a low pass filter for playback in MC, in DSP Studio - Parametric Equalizer. You can not apply the filter in the conversion and then apply it on playback. That lets you change the filter as needed without having to reconvert the files. I have the playback filter in place, but also apply it when I do a conversion, just in case I later want to play the tracks on a software/hardware package that does not do the filtering.

Note : The Parametric Equalizer settings for conversion and for playback use the same dialog box, but they are actually separate settings.
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