In the process of converting Flac files to Wav..have I gone mad!? Well, no actually..

Lets reiterate whats been said up thread it's not the file format itself but the on-the-fly transcoding that seems to bring about the apparent audible difference some peopple detect. Personally I've not noticed it and IVe done the Foobar ABX thing. What mechanism is at play here is anybody's guess.

On the file type itself, If you take a Wav file, create a duplicate, encode the duplicate, manually decode the Flac back to Wav and compare the duplicate to the original you will not find a difference. Perform a binary compare between the two and they will be identical.

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Originally Posted by Clive

It seems that most dacs do very little internal buffering (even though they often claim differently).

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I'm not sure what size the M-DAC's buffer is, however it's very obvious that the DAC is drawing it's data source from there, and there alone...so asynchronous, and subject to it's own timing constraints, which should theoretically remove jitter.

It's quite easy to see that the buffer is the soul source, there is a buffer level meter. Whenever there is a dropout in the buffer there is a dropout in the sound. If you try to use an SBTouch with an M-DAC without a USB hub you'll get plenty of these :eyebrows:

With a hub it's solid at 50% :)

I can't be arsed with all this mucking about with formats lark - I just play music these days :eyebrows:

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Originally Posted by WAD62

I'm not sure what size the M-DAC's buffer is, however it's very obvious that the DAC is drawing it's data source from there, and there alone...so asynchronous, and subject to it's own timing constraints, which should theoretically remove jitter.

It's quite easy to see that the buffer is the soul source, there is a buffer level meter. Whenever there is a dropout in the buffer there is a dropout in the sound. If you try to use an SBTouch with an M-DAC without a USB hub you'll get plenty of these :eyebrows:

With a hub it's solid at 50% :)

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I can't speak for the M-DAC as I've not played with one. What I do know it that JPLAY users report gains in sound quality due to reductions in buffers on the PC side even with async DACs using their own internal buffers. It's one of those things that is strange; you'd think that once the data is lined up in a DAC's buffer the manner in which it arrived should not matter, therefore Foobar, Jriver, JPLAY etc should all sound 100% identical if setup bitperfect. But they don't.

I did some testing with a squeezebox touch and server transcoding from FLAC to WAV a while back. I found that transcoding FLAC files to WAVs on the server rather than the Squeezebox Touch it increased CPU utilisation of the SBT about 25%. I presume this is the overhead of managing the network interface and buffer management within the Touch.

I thought that this was interesting as the rationale of using the touch toolbox 3.0 etc was to eliminate extra processing and allow the CPU to idle more, but this theory didn't appear to be bourne out in practice.

I couldn't tell the difference in a randomised play of WAV and FLAC versions of the same file either at all, despite listening hard for the increased openness etc. It sounds great either way to me, so I am pleased not to be suffering from format anxiety any more - am sticking with FLAC.

Cheers,
Alex

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Originally Posted by AlexM

I couldn't tell the difference in a randomised play of WAV and FLAC versions of the same file either at all, despite listening hard for the increased openness etc. It sounds great either way to me, so I am pleased not to be suffering from format anxiety any more - am sticking with FLAC.

Cheers,
Alex

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It's a good place to be :)

Agreed!

Always happy to find cheap (i.e. free) things that can add to the enjoyment of my music.
Its something I'll do once and forget about, its all automated in Jriver so not a drama.

No anxiety just curiosity. :)

Gary,

Just out of curiosity, have you ever tried or noticed this difference using SPDIF, or do you connect to the MDAC via USB only?. I am wondering if this is a PC-specific difference, and whether the Windows software/driver stack is affected by FLAC decoding and USB processing. I know you said that you said you saw an improvement on the SBT too, but maybe it is DAC specific (I presume you were using a DAC with the SBT - which one?).

I have to say that in my system at least, I am not yet totally convinced that async USB is the panacea that it is cracked up to be. In fact, I am finding SPDIF to sound significantly better than USB with the SB Touch and my Cambridge Azur 851C. I have yet to try this via my laptop, but I think I may revisit this.

Cheers,
Alex

Gaz - do you use "Play Files From Memory Instead of Disk" in Jriver Media Center?

I do - and I can't detect a difference between FLAC and WAV. My theory is that it unpacks the FLAC file to WAV before buffering in memory so by chosing this, so you are effectively playing WAV anyway... As I said MY theory, and not sure if it is how it works or not.

I'm certainly not going to convert nearly 2TB of FLACs back to WAV though, as I just can't tell the difference.

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Originally Posted by AlexM

Gary,

Just out of curiosity, have you ever tried or noticed this difference using SPDIF, or do you connect to the MDAC via USB only?. I am wondering if this is a PC-specific difference, and whether the Windows software/driver stack is affected by FLAC decoding and USB processing. I know you said that you said you saw an improvement on the SBT too, but maybe it is DAC specific (I presume you were using a DAC with the SBT - which one?).

I have to say that in my system at least, I am not yet totally convinced that async USB is the panacea that it is cracked up to be. In fact, I am finding SPDIF to sound significantly better than USB with the SB Touch and my Cambridge Azur 851C. I have yet to try this via my laptop, but I think I may revisit this.

Cheers,
Alex

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Hi Alex,
I take USB out from my server into a Vlink 192.
Its coax spdif from there into my Rega dac.
The Rega doesn't do 24/96 over usb hence the Vlink converter.

USB direct from the server doesn't sound as good as usb/spdif converted from the Vlink.

I bypass the Windows audio subsystem completely by outputting audio with Jriver set to "Wasapi Event Style exclusive access" output.
This enables the bitstream to pass to the Dac unaltered.

With the Touch I felt the improvement came from minimising the strain on its limited resources by getting the server to do the Flac>PCM number crunching.
The difference in the PC sound is similar but comes more from (imo) the additional on-the-fly processing rather than limited resources.

What I feel I have maybe done is take an unnecessary step out the chain?