Topic: 24/96 of a 1974 master analog?

[Belexes]

Someone on Dime asked if the seeder would post a 24/96 of a 1974 master he has.  That's fairly pointless is it not seeing as the master tape was not recorded in 24/96?

[ghellquist]

It depends. A good analog tape can have both a large dynamic and frequency range which can benefit from a bit more than the standard 44.1/16. Depending on the operator doing the transfer I believe the 24 bits is recommended.

It also depends on the AD converter as some of them does not quite deliver what you expect and can sound decidedly different on different sampling rates.

Gunnar

[boyacrobat]

get over 16/44
served us well BUT SERVES US NO MORE.

all analogue masters need to move from 16/44

g

[sunjan]

Someone on Dime asked if the seeder would post a 24/96 of a 1974 master he has.  That's fairly pointless is it not seeing as the master tape was not recorded in 24/96?

I'm with Gunnar and Moke on this.
Besides, the comparison you make between analog and digital is moot, since analog tapes are not recorded in bits... 

[Kevin Straker]

I'm fuzzy on how upsampling can insert meaningful information that was not there to begin with? I'm sure someone will enlighten me.

[aegert]

I'm fuzzy on how upsampling can insert meaningful information that was not there to begin with? I'm sure someone will enlighten me.

It is not an up-sample

You are sampling for the first time.. analogue does not have a Bit depth or sample rate.... :-)

A

[Brian]

as others have said it's not pointless at all.  as a matter of fact i'd transfer it at 24/192.  it's an analog source...might as well get as many samples per second as you can out of it! even if it is just a cassette

remember....when something is recorded on an analog medium, what's on the media IS the source.  when digital, it's just a "representation" of the source.

[Digital Quality]

What is the dynamic range of the cassette? I was thinking it's around 50dB but that's pretty much just a guess. I think the frequency response for tape is pretty high but the range is pretty low. If the range of magnetic tape is really around 50dB, then 24 bits would really be overkill IMO but you would still want a high sampling rate since the frequency response is so high.

[Roving Sign]

I'm fuzzy on how upsampling can insert meaningful information that was not there to begin with? I'm sure someone will enlighten me.

Its about capturing the sound wave in a more naturally rounded form, rather than the stepped staircase, chopped up effect, that you get with 16bit audio.
Of course you're not adding anything to what wasn't there to begin with. You're trying to keep analog more like analog in the digital domain.

Isnt that more about sampling rate than bit depth...? (stepped staircase)

[rastasean]

So if this fellow does want to convert this over to digital, what would be the best way to do this?

[Kevin Straker]

I'm fuzzy on how upsampling can insert meaningful information that was not there to begin with? I'm sure someone will enlighten me.

It is not an up-sample

You are sampling for the first time.. analogue does not have a Bit depth or sample rate.... :-)

A

Thanks, i should have realized that. The analog source will be just like being at a show.

[BlingFree]

So if this fellow does want to convert this over to digital, what would be the best way to do this?

Heres what Menke is doing..

MOTB Release: 0062 24/96
Release Date: 2008-03-07
Band: Grateful Dead
Date: 1979-11-25 (Sunday)
Venue: Pauley Pavilion - University of California
Location: Los Angeles, CA
Analog Audience Source: Master Cassettes [FOB, 60' from stage] (MAC)
Medium Stock Brands: MAC = Maxell UD XL II
Analog Lineage: 2 x Nakamichi CM-700 => Sony TC-D5 >> MAC
Analog Sound Preservation: MAC >> Nakamichi DR-8 => Korg MR-1000 >> DSF [1-bit 5.6448 MHz Stereo] >> Korg MR-1000 => Korg AudioGate >> WAV [24/96]
Taped By: Bob Menke
Transfer By: Bob Menke
Mastering By: Derek McCabe

[DSatz]

Imagine that you have a perfect recording medium that adds no noise whatsoever to any signal that you choose to record. Then imagine that you use this perfect medium to make a copy of an existing recording that has its noise floor at, say, 54 dB below full scale (the 0 level of the recording). Quick: What would be the noise level of the copy that you just made? That's right, it would be 54 dB below full scale.

The same is true if the recording medium is not perfect, but its noise floor is distinctly lower at all frequencies than the noise floor of the recording that you're copying. If the copy is being made on a system with a 95 dB noise floor and the original recording is as above, there will be no difference in the noise floor of the result--you might as well have made the copy with a perfect recording medium.

People, p-p-p-p-p-please let's get this straight: Word length in digital audio--the number of bits per sample--affects ONLY the dynamic range of the recording. You don't get any other improvements in sound quality whatsoever. More bits per sample won't give you "rounder" or less "stairstepped" signals, lower distortion, better "resolution," better sound quality at low levels (apart from the effect that noise always has, just like in analog media). More bits per sample simply makes the noise floor lower. So if you're recording a signal that has a lot more noise than the medium you're recording it onto, there's simply nothing to be gain by increasing the number of bits per sample far past the dynamic range of your source material.

It's 6.02 dB per bit, so you can easily do the math. If this is a very carefully made Dolby "B" cassette recording on pure metal tape (which was newly available in around 1974), 11 bits would be enough to render it. Of course you want the noise floor of the digital transfer to be several dB below the noise floor of the cassette all across the audio frequency range, so by all means go for 12 bits. But don't expect any sonic improvement beyond about 12 bits because by then the noise floor of the digital channel is much lower than the noise floor of the signal you're recording.

I'm sorry but all the references in this thread to "stairsteps" and such are simply wrong and the people who are saying them need to find out how digital audio recording actually works and stop giving advice until they have so learned. There, I've said it--I truly don't mean to antagonize any individuals in this very nice place, but some things are a matter of opinion while others are a matter of knowing how something actually works or doesn't work. Which you only prove that you don't know, if you speak of stairsteps. That metaphor outlived its usefulness in the 1980s. Die, metaphor, die.

--best regards

[sunjan]

It's 6.02 dB per bit, so you can easily do the math. If this is a very carefully made Dolby "B" cassette recording on pure metal tape (which was newly available in around 1974), 11 bits would be enough to render it. Of course you want the noise floor of the digital transfer to be several dB below the noise floor of the cassette all across the audio frequency range, so by all means go for 12 bits. But don't expect any sonic improvement beyond about 12 bits because by then the noise floor of the digital channel is much lower than the noise floor of the signal you're recording.

Thanks for clearing this up, DSatz!
But all that being said, wouldn't you agree that it's still better to do the first A>D transfer at a higher bit rate, allowing more editing in post? And downsample to 12 bits (or 16 bit, whatever) for the final output???
In practice, how would you perform this operation?

/J

[aegert]

Moke +T

I am with you on that... I think that sample rate plays a very big part in sound as well. I really don't want to get in an argument so I won't be detailed about it.. Forum threads usually degrade over this discussion...

From a qualitative perspective 24 bit sounds better... and it affords better editing results.

Higher sample rates make things sound better to me as well.

I think there is a lot lost in the quantitative discussion .. Yes gear designed for certain rates and bits will sound better at them and yes filters for one sound better than at others.. Yes the math plays out differently but I am constantly amazed at the difference I hear...

Now is that a Placebo effect? maybe... But if you believe that saltwater cures cancer and your belief proves to convince your third eye of that truth and your cancer goes away because you believed and healed yourself.... Would you take the placebo or say the math shows something different? LOL

I do feel that the higher and faster you go from an archive perspective gives you the better chance in the near and distant future to revisit the piece and help it out with newer technology.

You can't put Bits or sample in after that fact you will always still have your effective resolution so I do everything as best as I can and damn the torpedos!

Love A