Print

Print


Hi Andrew:

Any scientific measurement of bass input vs. output shows that 88.2 works just fine for 
analog-digital transfers. But, as I often say, horses for courses. If you like 55kHz sampling rate, 
enjoy. If you do work for anyone who's getting grant funding, you probably have to adhere to NARAS 
specifications and use 96kHz.

The rest of your posting seems to be a slag of PCM in general, that it's allegedly not reproducing 
some sort of "automagic" (your word), which is fine for an opinion but I choose not to argue over 
it. Digital denial is fine, but the rest of the world has moved on. My opinion is that it's ignorant 
to dismiss a technology because of flaws -- real or perceived -- in implementing it (or using it, 
for that matter).

I can't imagine a frame of reference where a mass duped cassette sounds "better" than a CD (assuming 
same master source and competent production of both media). Some seem to prefer added hiss and 
distortion as "euphonic," so I can imagine a frame of reference where a cassette recorded on a good 
cassette deck from a favorite LP would be preferred to a CD-resolution A-D transfer of the same LP, 
although I certainly don't share that frame of reference.

-- Tom Fine


----- Original Message ----- 
From: "Andrew Hamilton" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, April 11, 2012 1:40 PM
Subject: Re: [ARSCLIST] Recording_78rpm_records


On 4/11/12 12:14 PM, "Tom Fine" <[log in to unmask]> wrote:

> To prove Karl's point, and I am sure this experience is not unique, I
> encountered a stereo LP this
> morning that had the exact kind of vinyl "pimple" described previously. The
> pops and ticks
> transferred just fine at 88.2/24-bit PCM, despite being very sharp rise times
> and dropoffs. They are
> definitely not square waves, but they rise quickly between samples. The
> waveform editor did not show
> any "ringing" at the top of the rise, and the dropoff was uniform also, so I
> conclude that PCM
> sampling captures these as they are produced by the analog equipment.

I hope it's understood that what I wrote before in this thread was, "...the
pops and clicks are near square waves, in terms of their rise times..."  -
not that a click or pop = square wave.  They propagate suddenly. The clicks
which propagate more suddenly than 3.6 µs, when sampled at 88.2 kHz Fs, are
simply not encoded - whence the absence of perturbation.   Still, that's a
nice fast sample rate which, according to Dan Lavry, is technically too fast
for perfect accuracy of the bass.  55 kHz is the current sampling speed
limit, according to the designer.  88.2 kHz is good for this test, however,
since we are talking about high frequency events.  Still, the music may be
best at 48 kHz Fs, in spite of the worse Squarepushing.  It was suggested to
me that program with only a few instruments (chamber music or solos?) would
be best at 48 kHz, and music more rich in overtones would possibly be better
at 88.2 kHz.


> It is
> also clear that the
> needle is not leaving the groove because the pops "ride" on top of the music
> waveform and thus can
> easily be edited out with the pencil tool. When they occur during pauses in
> the music, they are
> clearly "riding" on top of the surface noise and rumble. This can easily be
> seen by zooming in far
> enough in the waveform editor. It was reasonable ambient humidity and the
> vinyl was not carrying a
> bad static charge, so I didn't encounter any of the saturation-pops to
> analize, but I have done that
> previously and stand by my previous description, adding that those, too, are
> not square waves.

Here's what I sent to one of the thread responders about the term, square
wave, as I used it, earlier, in this thread.   Perhaps we can get some kind
of "rise" out of it:


" The square wave's rise time is what was described as happening in clicks
and pops in this thread.  Not [actual] brief, but perfect, squares. Yes,
impulse-like.  Not pure impulses, of course, which would happen in less than
a measurable length of time... (instantaneous propagation)

Square waves - which are sudden - are created by summing many frequencies
together, over many octaves.  Square waves are meant nearly to be forming
with the summed overtones of a full orchestra hit, according to my
protected, and infallible, source.

Digital audio sampling at, say, 96 kHz has radical attenuation above 48 kHz.
This means that normal LPCM release formats can't "approach" the square wave
as well as can its analog counterparts.  Faster than 48 kHz Fs LPCM, also,
is less accurate with the low frequency audio content, due to settling time
requirements being exceeded (according to Lavry, who don't offer rates above
96 kHz Fs in their high end professional equipment).  Once you go to DSD,
there's too much hf noise that needs to be filtered for square wave
bandwidths to be cleanly decoded.

There's an urban legend going around which might be true that Stan Ricker
found he had recorded the tape recorder bias signal (over 100k) on a lacquer
disc.  It was very quiet, but not silenced.  That would approach DXD
bandwidth, albeit quietly...





> Karl is correct that no equipment, digital or analog, can reproduce all square
> waves and impulses,
> but good ones can handle that information within the bandwidth of human
> hearing. And, in defense of
> the CD format, if 44.1/16 were so limited in the ability to capture, process
> and reproduce square
> waves and impulses, then almost all synthesizers would sound like total crap
> on CD, and
> "electronica" as a music genre would have never risen up in the CD era.

CD alias-dampening is not by any means a deal-breaker.  It's a question of
high fidelity, only.



> The
> same can be said for
> highyl-synthesized genres like hip-hop, 80's pop-rock and post-disco dance
> music, not to mention
> movie soundtracks. Yes, there is more "there" there with higher-resolution PCM
> digital, but there's
> a lot of "there" with the Red Book resolution and it can jump out at you
> better without tape hiss or
> LP surface noise and rumble competing with it.

Too much of the wrong, "there," and not enough of the automagic
enhancements, as well as the ability "to approach" the square wave with
derived integrity.

> Given that, by the time CDs
> took hold as a mass
> medium, the most popular mass medium for music distribution was fast-duped
> cassettes, the Compact
> Disc was a great leap forward

In certain measurable ways, LPCM is like an elegant advanced alien audio
technology.  In others, it is like Big Brother's electronic harassment for
crowd dispersal.  Depends on where you place the probe. I agree that most
CDs sound clean (in an antiseptic and glassy or white noise, sort of a way)
.  But I listened to those old cassettes so many times the rust was
practically rubbed off.  You can have most of the CD's I've bought over the
last 30 years.  What shrill junk.  (:   Rhetorically offered, only - I might
need them for critical reference, still., (l;


> (cassettes outsold LPs soon after the Walkman
> Revolution took hold;
> CDs didn't outsell cassettes until the early 1990s -- see numerous references
> and industry data
> available online).

OK, but sales are one thing and good sound may be something else.  People
bought those Blue Amerols, since that's what was up, and it was once "new."
Ringtones are cooler, nowadays, than CDs, aren't they.  The Target® depends
on the shopper.







Andrew






> -- Tom Fine
>
> ----- Original Message -----
> From: "Karl Fitzke" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Wednesday, April 11, 2012 11:20 AM
> Subject: Re: [ARSCLIST] Recording_78rpm_records
>
>
>> Dale's question (or I suspect, point made in the form of a question) is right
>> on the mark.
>>
>> All electronic systems, analog or digital, have their limits.  The ability to
>> record, reproduce,
>> process, square waves or short impulses for example, depends on a system's
>> high frequency response
>> and dynamic range.  There is NO technology out there that can record a pure
>> square wave or
>> infinitely short impulse.  Some systems are of course better than others at
>> recording audio band
>> square waves, impulses, and complex waveforms with important high frequency
>> content.  But whether
>> they are digital or analog is not the determining factor.
>>
>> It's a mistake to close our minds to digital audio, and its most prominently
>> employed sampling
>> methodology, Linear Pulse Code Modulation (LPCM), just because we might be
>> dissatisfied with CD
>> quality digital audio (16-bit 44.1 kHz sample rate LPCM).
>>
>> Regards,
>> Karl
>>
>> On 4/11/12 7:04 AM, D. Allen wrote:
>>> Dale Francis
>>>
>>> On Apr 11, 2012, at 2:05, "Andrew S. Hamilton"<[log in to unmask]>  wrote:
>>>
>>>>   It's that the pops and clicks are near square waves, in terms of their
>>>> rise times, and digital
>>>> can only capture sines.  So, it changes the attack and harmonics of the
>>>> surface noise and makes
>>>> it ugly, whereas the same noises on the vinyl are easy to ignore and might
>>>> even be exciting>?<
>>>> Incidentally, he said this is also why digital fails to deliver, musically,
>>>> even though it does
>>>> great telephony, since the combined harmonic overtones of a full orchestra
>>>> during a fortissimo
>>>> would approach a square wave on an oscilloscope, but the CD can't make that
>>>> happen.   So, for
>>>> all its accuracy and quietude, its just a stomp box (LPCM).
>>>>
>>>>
>>>> Cheers,
>>>>      Andrew
>>>
>>> Can either a phono cartridge or a speaker can accurately encounter a square
>>> wave without side
>>> issues ... needle leaving groove ...
>>
>> -- 
>>
>> Karl Fitzke
>> Audio Engineer
>> Macaulay Library
>> Cornell Lab of Ornithology
>> 159 Sapsucker Woods Road
>> Ithaca, NY 14850
>>
>> 607-254-1100
>>
>> [log in to unmask]
>>
>> Our Mission:
>> To interpret and conserve the Earth's biological diversity through research,
>> education, and
>> citizen science focused on birds.
>>

-- 
Serif Sound ♬ CD Premastering
     www.serifsound.com

➣ Dingbat Lacquer Sound Disc
     www.dingbatlsd.com

513-542-3555
2836 Spring Grove Avenue
Cincinnati, Ohio
45225