Testing 24-bit, 96 kHz FLAC?

[ezkcdude]

I just finished building my DAC, and it works, and now I want to test it. The DAC upsamples (or downsamples) to 96 kHz. So, I went looking for FLACs on the Live Music Archive. I found some recent 24-bit, 96 kHZ files of a Drive-by-Truckers concert. Seems like a great test. What will the SqueezeBox output if I play these files?

[krochat]

I found some recent 24-bit, 96 kHZ files of a Drive-by-Truckers concert. Seems like a great test. What will the SqueezeBox output if I play these files?

Assuming you're running slimServer 6.5, 48kHz x 24bit on the digital outputs, and probably the same feeding into the DAC if you're using the analog outputs. Try it, you'll like it!

[ezkcdude]

Assuming you're running slimServer 6.5, 48kHz x 24bit on the digital outputs, and probably the same feeding into the DAC if you're using the analog outputs. Try it, you'll like it!

That's kind of what I figured. Good enough for now, though.

[DCtoDaylight]

I asked this question a while ago, but never did get a final answer...

The Transporter claims to support 24/96 on it's digital outputs. Anybody tested this yet? And if you stream a 24/96 source, what do the SB3's do? Downsample? or are they capable of 24/96 on their digital outputs as well?

Sign me curious!

Dave

[krochat]

The Transporter claims to support 24/96 on it's digital outputs. Anybody tested this yet? And if you stream a 24/96 source, what do the SB3's do? Downsample? or are they capable of 24/96 on their digital outputs as well?

Starting with SlimServer 6.5, 24/96 material is downsampled on the server side to 24/48 prior to sending it to the SB3. It still sounds very similar to the 24/96 feed direct from my PC.

No transporter here, so I can't test 24/96 the output.

[ntom]

Was just giving some thought to recording my album collection for SB3. Anyone have a view as to whether it would be worth attempting 24/96 recording....? If so any suggestions for suitable sensibly priced A/D for PC....?
If not I have a digital recorder that offers 44.1 but still need a spdif i/p for PC....any cards recomended or any to avoid?

Thanks, Neale

[pfarrell]

ntom wrote:
> Was just giving some thought to recording my album collection for SB3.
> Anyone have a view as to whether it would be worth attempting 24/96
> recording....? If so any suggestions for suitable sensibly priced A/D
> for PC....?
> If not I have a digital recorder that offers 44.1 but still need a
> spdif i/p for PC....any cards recomended or any to avoid?

I already had 16 channels of 24/96 IO in my studio, plus a serious
turntable (or at least serious 15 years ago) with a brand new cartridge.
I did four or five LPs.

My opinion is that it is not worth it for albums that are still
available, in print, or whatever the phrase is.

The sound quality was not wonderful, mostly because the LPs were played
and loved. Surface noise, etc., was bad. I tried using some of the noise
removal plug-ins from my studio's DAW software, and decided that I'd
rather have the occasional surface noise than the phase distortion that
the plug-ins caused. I was able to use the DAW software to selectively
torn on the noise removal for only the clicks, but that is a manual process.

I also found that the quality of the preamp was critical. I had my own
Dynaco PAT-5 from the early 70s, and it was pretty bad. Could have just
been bad capacitors after sitting so long. So I ended up having to get a
good preamp with an accurate RIAA equalization curve. (Your local Guitar
Center's DJ section has a fair selection, lower than the insane prices
of most Audiophile vinyl preamps.

So I decided to buy CDs were they were available. The only LPs that I
continued to transfer were the ones that were out of print and special,
mostly jazz from the late 60s and 70s that never made it to CD.

If you are serious about quality, you have to have a ADC that is
external to the PC. Nothing about the insides of a PC is compatible with
quality analog signals. I have two sets of M-Audio Delta 1010s, which
were fairly cool when I got them, but they are now old. They are a lot
cheaper now than when I bought them.

I could be wrong, but I thought that once it was digital, the SPDIF
input's quality makes next to zero difference.

--
Pat Farrell PRC recording studio
http://www.pfarrell.com/PRC

[stevo]

I thought that this was worth reading.

http://www.hifi-writer.com/he/dvdaudio/dvdvscd.htm

"First, my preconceptions: I was inclined to think that there would be no audible differences between the two media. For me at least. On the other hand, I earnestly hoped that I would hear some difference between the media. Failing to do so tends to put one's credibility as a writer on such matters on the line. So to the extent that our subjective impressions are influenced by our expectations and hopes, I think I was fairly balanced."

and

"This leads me into DVD vs CD. I cannot confidently say that there are no differences in the sound delivery of the two media. But I can insist that anyone who uses language of the 'chalk and cheese' variety is fooling him or herself. The differences, if there are indeed any, are very subtle indeed. So before equivocating further, I'd better write what I felt I noticed."

[cliveb]

ntom wrote:[color=blue]
> Was just giving some thought to recording my album collection for SB3.
> Anyone have a view as to whether it would be worth attempting 24/96
> recording....?

My personal opinion is that 16/44.1 is plenty good enough for vinyl transfers, and it's not because I'm not interested in getting the best from LPs. (My vinyl transfer setup uses a Linn LP12/Lingo/Ittok/Karma and a Naim preamp). Others hold differing views, and I am sure they may pop in to give you their side of the story.

My opinion is that it is not worth it for albums that are still
available, in print, or whatever the phrase is.

I agree, with the additional caveat that some CD reissues of LPs have been butchered (either by editing, remixing, or hypercompression). In those cases, you may feel that a transfer of the original LP is preferable.

If you are serious about quality, you have to have a ADC that is
external to the PC. Nothing about the insides of a PC is compatible with
quality analog signals.

Of course it's true that the inside of a PC is awash with RFI, but the amazing thing is that there are plenty of decent soundcards out there that seem immune to it. The Lynx Two and DAL Card Deluxe are the obvious examples at the very high end. But even the humble M-Audio AP2496 (available for under $100) achieves a S/N ratio around the 93dB mark, which is plenty good enough for vinyl.

I could be wrong, but I thought that once it was digital, the SPDIF
input's quality makes next to zero difference.

If you do use an external A/D converter running at 44.1kHz, you need to be careful. Many of the cheaper mainstream cards that have SPDIF inputs (eg. Soundblasters) resample the incoming stream to their internal clock speed (48kHz), and since they do it in real time, tend not to make a particularly good job of it.

[tommypeters]

Starting with SlimServer 6.5, 24/96 material is downsampled on the server side to 24/48 prior to sending it to the SB3. It still sounds very similar to the 24/96 feed direct from my PC.

I think I've read that this is instead done on the SB side, the SB3 is simply throwing away every other sample. This (of course) uses double the bandwidth, but is transparent for use with a Transport that can use all that's sent to it of the 24/96 feed.