14K is an A and 21K is an E, so it's a 5th.
On Mon, Nov 23, 2015 at 2:25 PM, Dave Burnham <[log in to unmask]> wrote:
> When I was born, (1942), we didn't even have 78s; we only had records. If
> you had gone into a record store and asked if they sold 78s, they probably
> would just looked at you blankly; that all changed in 1948 when LPs were
> In spite of the gifted hearing that my friends and family give me credit
> for having, I, of course, have never HEARD bias except as I described when
> "rocking" tape at slow speed. So it's probably a non-issue. Now, naturally,
> my hearing is not near as good as it was when I was younger, but I was
> encouraged by a comment posted here several months ago that the difference
> between the 21k I could once here and the 14k I may be able to hear now is
> only a few notes of the scale.
> Sent from my iPhone
> > On Nov 23, 2015, at 11:37 AM, Tom Fine <[log in to unmask]>
> > Hi Dave:
> > 1. most if not all professional tape machines had a "bias trap"
> (low-pass filter) to block bias interfering with playback. Keep in mind
> that early tape recorders, and especially early magnetic film recorders,
> had relatively low bias frequencies (several well under 100kHz), which
> could beat with some audible frequencies. So the bias trap was an early
> known thing in magnetic recorder design.
> > 2. in the case of a Plangent transfer, a separate electronics path
> recovers bias, onto a separate digital track. The audio tracks do not have
> any bias interaction or "pollution." John Chester can explain this in
> better detail, since he built the electronics.
> > Also, I agree very much with John Chester's point that the digital
> "recording" system must introduce as few distortions or errors or anything
> else as is technically possible, because all of that compounds on the
> playback errors from the analog source. One thing we haven't discussed is
> that there are many different ADC designs, some offering a more transparent
> analog front end and also some being better able to deal with peak-levels
> from the source than others (ie analog headroom -- you certainly don't
> want overload distortion to happen before something is digitized). The
> thing that I find very impressive about the march of knowledge and
> technology is that we have these kinds of tools today, at affordable
> prices. This has all happened in my lifetime. When I was born (1966), NHK
> had not yet developed a reasonable-fidelity digital audio recorder.
> > -- Tom Fine
> > ----- Original Message ----- From: "DAVID BURNHAM" <[log in to unmask]>
> > To: <[log in to unmask]>
> > Sent: Monday, November 23, 2015 10:50 AM
> > Subject: Re: [ARSCLIST] What is really higher resolution?
> > Well also, (and I haven't read about this anywhere but it seems
> plausible), the analog signal on a reel to reel tape is riding on a high
> frequency bias. This bias signal is on the tape as an audio signal,
> (plainly heard if you are "rocking" the tape across the head at a very slow
> speed. If you're sampling at 196khz, I can visualize some interference
> between the bias frequency and the sampling frequency unless a low pass
> filter completely removes the bias frequency.
> > d
> > On Monday, November 23, 2015 8:42 AM, Tom Fine <
> [log in to unmask]> wrote:
> > Correction -- I meant to say:
> > "Then there's the fact that some tapes AREN'T slit perfectly enough to
> ride through the transport
> > with relatively even track-tracking (i.e. relatively perfect azimuth
> throughout the tape)."
> > For what it's worth, Irish/Ampex/Quantegy battled slitting-imperfection
> issues throughout its
> > existence. 3M slitting was generally better, as was BASF and Agfa and,
> I'm guessing (due to no
> > experience with the product), EMI. Audio Devices (AudioTape) was also
> generally slit precisely.
> > Keep in mind too that age physically distorts some tapes, so the ride
> across the heads is even less
> > perfect. We all know about acetate tapes warping and curling and
> shrinking. There hasn't been much
> > science done on baking polyester tapes and whether that creates
> transport-azimuth issues. My own
> > experience is that some tapes do have issues because, after baking,
> there is some non-sticky residue
> > on the tape surface and edges. This problem can probably be mitigated by
> running a baked tape across
> > a Pelon wipe before transfer.
> > My main point is -- and you can test this with sine-wave and square-wave
> signals on even the most
> > modern and well-maintained tape machines -- tape is far from
> output=input, so it's falacious to say
> > its output is "steady-state" fidelity to the original source. Tape's own
> mechanical and electrical
> > imperfections are constantly "chopping bits off" the original signal,
> and thus reducing resolution.
> > Same with disk recording and playback.
> > -- Tom Fine
> > ----- Original Message ----- From: "Tom Fine" <[log in to unmask]
> > To: <[log in to unmask]>
> > Sent: Monday, November 23, 2015 7:27 AM
> > Subject: [ARSCLIST] What is really higher resolution?
> >> There is an argument to be made that analog media playback can't
> possibly offer that many data
> >> points to be collected. To wit ...
> >> 1. when you play a tape, you are fighting the laws of physics. For one
> thing, no transport
> >> provides a perfect ride across the heads. Resolution is damaged by wow
> and flutter (time-smear),
> >> plus imperfect tape-to-head contact cause by anything from uneven head
> wear to imperfections in
> >> the tape surface to simple dust and other particles in the air. There's
> also static electricity
> >> and other results of friction. Then there's the fact that some tapes
> are slit perfectly enough to
> >> ride through the transport with relatively even track-tracking (i.e.
> relatively perfect azimuth
> >> throughout the tape). Tape electronics, especially old ones, are prone
> to what are now considered
> >> high levels of distortion and noise, and unless they have been
> thoroughly overhauled, aging
> >> components compound these problems.
> >> 2. a commercial disk release has mechanically-lowered resolution from
> the get-go. There are some
> >> issues with lacquer "memory" (where the groove shrinks back a little
> bit when it cools after
> >> cutting -- this is a controversial topic among cutting engineers, but
> direct-metal mastering was
> >> invented as a solution to this alleged problem). Then there is
> resolution-loss in the plating
> >> process, because the laws of materials science and physics say it's
> impossible to make a perfect
> >> imprint (there is some granularity to all materials, plating cannot be
> perfectly uniform, etc).
> >> And, the pressing machines can't be perfectly clean on every press, the
> vinyl biscuit can't be
> >> perfectly pure, etc. In fact, if you think about disk-manufacturing,
> it's quite miraculous that
> >> the whole system got to where it can sound as good as some records do.
> With shellac records, it's
> >> even more so because the technologies hadn't evolved as much and
> shellac itself is a very
> >> imperfect carrier material. So, before a stylus even hits the groove,
> you have stages of materials
> >> imperfections baked in (literally), which results in at least surface
> noise if not ticks, pops and
> >> groove distortion. And then there's the matter that no stylus tracks a
> groove perfectly, there is
> >> an inherent noise floor in all mechanical playback (dragging a diamond
> through a groove), and that
> >> only the very best preamps offer super-low noise floors (this is even
> more of an issue with
> >> low-output moving-coil setups).
> >> One argument made by the anti-digital crowd of yore (I don't hear this
> argument made about
> >> higher-resolution digital, except by ideologue zealots) is, "no matter
> how much you sample a sound
> >> wave, you're still breaking it into chunks and it's not a steady-state
> wave." But, see above. The
> >> output from the analog playback system itself is not really a
> steady-state wave. Physics and
> >> materials science prevent that from being so. So the question is, which
> system is actually
> >> capturing more "resolution"? Let the debate begin!
> >> -- Tom Fine
> >> ----- Original Message ----- From: "Corey Bailey" <
> [log in to unmask]>
> >> To: <[log in to unmask]>
> >> Sent: Monday, November 23, 2015 3:14 AM
> >> Subject: Re: [ARSCLIST] Hi-Rez symphony recordings
> >>> Correction:
> >>> Data points per bit should have read: data points per dB of dynamic
> range (I changed the math,
> >>> but not the description).
> >>> So, the comparison should read:
> >>> Lets take a look at the available data points for each dB of dynamic
> range for CD quality digital
> >>> audio: 65,536 (data points) divided by 96 (dB of dynamic range) =
> 682.6 data points for each dB
> >>> of dynamic range of a given sample.
> >>> Compare that to 24 Bit/ 96K digital audio: 4,294,967,296 (data points)
> divided by 144 (dB of
> >>> dynamic range) = 29,826,161 data points for each dB of dynamic range
> of a given sample. And,
> >>> there are more than twice a many samples taken! Now, we are talking
> about some decent resolution.
> >>> Also, my hand typed chart got wacked by the forum formatting.
> Hopefully, you get the idea.
> >>> Cheers!
> >>> Corey
> >>> Corey Bailey Audio Engineering
> >>> www.baileyzone.net
> >>>> On 11/22/2015 7:47 PM, Corey Bailey wrote:
> >>>> Mr. Kevil:
> >>>> Let's take a look at Bit Depth as applied to digital audio: "Bit
> Depth divides a given sample
> >>>> by its value."
> >>>> Thus:
> >>>> BIT DEPTH DATA POINTS DYNAMIC RANGE
> >>>> 8 256 48dB
> >>>> 16 65,536 96dB
> >>>> 24 4,294,967,296 144dB
> >>>> Now, lets take a look at the available data points per bit for CD
> quality digital audio: 65,536
> >>>> (data points) divided by 96 (dB of dynamic range) = 682.6 data points
> for each bit of a given
> >>>> sample.
> >>>> Compare that to 24 Bit/ 96K digital audio: 4,294,967,296 (data
> points) divided by 144 (dB of
> >>>> dynamic range) = 29,826,161 data points for each bit of a given
> sample. And, there are more than
> >>>> twice a many samples taken! Now, we are talking about some decent
> >>>> So, even though you have only 70 dB of dynamic range available for
> those old tape recordings
> >>>> (before the introduction of Noise Reduction), you will obviously
> capture much more of that
> >>>> available dynamic range using the archival standard 24Bit/96K (Hi
> Rez) sample rate and bit
> >>>> depth.
> >>>> The same logic applies to any of the old audio carriers.
> >>>> Plus, when restoration takes place, the results are less artifact
> prone when using higher bit
> >>>> depths and sample rates.
> >>>> Cheers!
> >>>> Corey
> >>>> Corey Bailey Audio Engineering
> >>>> www.baileyzone.net
> >>>>> On 11/22/2015 3:03 PM, L. Hunter Kevil wrote:
> >>>>> A transfer of a 1960s tape marketed in a 24/96 wrapper is what?
> Doesn't the resolution of the
> >>>>> tape correspond to the equivalent of an 8- or 12-bit word? If so,
> what does the wrapper do?
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