Which recording options, sample rate and bit depth

[Jos van Eekelen]

For transferring vinyl to digital (Squeezebox) I have chosen 48 kHz/24 bits per sample/FLAC compression but after reading the threads about the ASIO driver I'm having some questions. I have chosen the above settings because it's a tad better than vinyl, leaving some room for correction etc. My input device (Cakewalk UA1G) has the same settings. Althought the ASIO driver is installed the standard Windows driver is used since VS does not support ASIO (yet). I don't mind about latency, my lp-s are more than 30 years old so a few milliseconds don't matter. Sound quality is my main concern.
My question concerns the digital handling of the data. UA1G outputs 48 kHz/24 bits. Will VS or Windows alter the data or transfer them to disk without any modification? What happens if I choose other settings in VS, will the data then be converted by VS and will this affect the quality? How about the cleanup process in VS, are the data handled "as is" or is it transferred to a standard VS format (44.1 kHz/16 bits)?
I look forward to your reply, I'm not overly worried about this since VS does a great job but just curious. Paul: perhaps it's a good idea to put some info about this in the FAQ or manual. The support of non-CD settings seems to have sneaked in into version 8 (or earlier) and raises questions like the above.

[Paul Sanders (AlpineSoft)]

Hi,

VinylStudio only converts the audio when you ask it to.  This is either (a) when you burn an audio CD (in which case the data is converted to 44kHz 16 bit) or, at your option, when you save your tracks.  All processing within VinylStudio itself is done at the original sample rate and bit depth.

As for choosing a different sample rate or bit depth at record time, it pays to use something supported natively by your hardware.  Otherwise a conversion is done.

[Jos van Eekelen]

Hi Paul,
Thanks for your reply. Previously I had assumed that the data would not have been altered but the discussion about the ASIO driver made me doubt. I intend to do some testing but that's not so easy since recording and playback levels can play an important role in comparing sound quality.

[Paul Sanders (AlpineSoft)]

Hi,

There's now a beta-test version of VinylStudio which supports ASIO.  If you'd like to try it we'd be grateful.  You can get it from here:

http://www.alpinesoft.co.uk/VinylStudio/VSInstall_V8_20B1.exe

Please let us know how it goes.

[bjornvinyl]

Hi,

I've been using VinylStudio for some time now and it does a wonderful job of capturing my precious records. W.r.t. this subject I would suggest that VinylStudio shows which type of input it "senses", i.e. sampling rate and bit depth. A great place to add this information would be when you do the level check. This would help choosing a suitable recording format and sort out some confusion (in my case) regarding which signal I am actually recording when I connect my Harman Kardon HK 990 (no digital spec. seems to be available) with the optical input of my Mac mini running Lion. Since recording a takes a long time it would be good to make the right choice from the beginning.

[Paul Sanders (AlpineSoft)]

Yes, we will add something.

[bjornvinyl]

That will be great!

Another feature I would appreciate is to add another option when normalising the album. Normalising is really helpful, but since the gain applied is usually a decimal number it seems to me that the audio waveform will be resampled - right? To avoid this, and its possible sound degradation, one could perhaps offer an option in the digital domain. That would be normalising with a gain of 2, 4, 8, ... times the recorded signal, i.e. just shifting the bits in the audio samples. Any thoughts?

Thanks again for an already great software!

[Paul Sanders (AlpineSoft)]

The audio is scaled, rather than resampled.  The error introduced is minimal.  Limiting the gain values to powers of 2 would be overly restrictive.

[bjornvinyl]

OK,

I see your point but my suggestion would rather be to expand the options of normalising to achieve maximum quality when possible. When recording from my digital input on my Mac I often have maximum meter response between 20-50% (depending on the recording, nonadjustable) which would benefit from 4 or 2 times multiplication of the signal.

Best regards.

[Paul Sanders (AlpineSoft)]

In that case, you might want to record at 44 kHz 24 bit.  That probably offers the most 'bang for the buck'.

[drystream]

Paul,
I wonder if you could comment a little further on your thoughts about sampling rate.

Given that disk storage space isn't an issue, in your experience have you seen any sonic improvement by recording at the higher rates?  Some people insist that 24/192 files are essential to capturing the subtleties of LPs.

I've recorded many of my albums at 16/44.1, some at 24/48, and a few at 24/96, although I've only used the computer's A/D converter for importing.  I haven't been able to hear any significant difference between these sampling rates.  However, I also have a DAC that uses the ESS 9018 chip that over-samples the incoming signal 386x -- so I'm not really sure what I'm hearing as the final output.

The reason I ask about this is that I got a good deal on a quality A/D converter that claims to reduce jitter and improve the audio signal being recorded.  I can record at up to 24/96, but am unsure if going to the highest bit depth/sampling rate gains me anything over the lower resolution files.

I guess the short answer would be, 'why not?'  If I've got the storage space for the files maybe just record at the highest resolution and don't obsess over what rate to use.

Anyhow, your thoughts on this subject would be appreciated.

[Paul Sanders (AlpineSoft)]

Well, smaller files are always easier to deal with.  They transfer and back up quicker, for example.

I really don't have a specific recommendation for which sample rate to use.  I think it's a matter of personal choice and you need to let your ears decide.  I personally used 16/44 and am quite happy with the results.

[bjornvinyl]

Hi,

I previously asked for a display of sampling rate and bit depth in VinylStudio. Now, when version 8.2 has arrived, there is a button displaying the possible sample rates and bit depths for the sound card. Even though informative this is not what I intended. I would like to know the specification of the digital signal actually delivered to VinylStudio. This should be only one of the options now displayed. Would this be possible?

[Paul Sanders (AlpineSoft)]

Actually, no, at least not on Windows XP.  Windows always supplies the format asked for, even if a conversion is needed.  The new display is intended to help you make an intelligent choice of sample rate and bit depth to record at.

[erniemit]

Bjorn,

What ADC are you using to give you 24 bit x 96 bit-stream?     My NAD phono preamp only sends 16 b x 48 via USB.   However, I can tell the difference between 16 b recording and 24 b recording, so i guess up-converting works.   My Cambridge DAC Magic is a great up-scaling DAC, but the difference is still there (only with great speakers to hear the differences).   I heard from a pro, that owns a store that is registered to sell Audio Research and Mangepan, that the lesser the DAC, the more the differences can be heard between the two.