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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. 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.

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. 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. 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 (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).

-- 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
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