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80 Million bps Analog Tape

watchnerd

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While shopping for some reel to reel analog tape, I ran into this statement:

"To understand why, a professional tape recorder provides the most lifelike reproduction revolves around a couple of important factors. The key lies in the inherent technology of the tape itself. Audio tape in use during the 1950s and ’60s provided approximately 65,000,000 magnetic particles per second of recording a quarter inch format at 15 inches per second (ips) tape speed. Each magnetic oxide particle or groups of particles takes on either a north or south orientation after exiting the recording head. Starting to sound like digital bit stream? Well yes and no. However there is one huge difference between analog tape recordings and even the best digital recordings.
RESOLUTION
The highest digital resolution today offers 4,608,000 bits switching per second. Not bad. Big improvement over the standard Red Book CD but it is not even close to sub-micron particle resolution of ATR Master Tape.
RANDOM PARTICLE STACKING
Quarter inch, two track ATR Master Tape running at 15 inches per second (ips) involves approximately 80,000,000 oriented and randomly stacked particles per track second. It’s not just the particle count but the random stacking that turns this super binary resolution into pure analog playback. This is why even a narrow track width recording still sounds so detailed despite the lower surface area."

https://www.atrtape.com/sound-of-tape/

How big is a magnetic particle?

Is that a molecule?

An atom?

A quark?

A chunk of metallic oxide dust or dirt?
 

solderdude

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Me thinks ... gap width/azimuth/tapespeed/alignments.... the magnetic direction also is not 'digital' as in north or south.
 

derp1n

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Bob Stuart needs to barf up some MQA-Tape format to take advantage of this incredible discovery.
 

Wombat

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Whatever. It is still a coating on a problematic substrate. o_O
 

bennetng

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Reality...
http://www.broadcaststore.com/pdf/model/10728/PCM-3348.pdf
Supported by its highly reliable tape transport and refined servo
control system, the PCM-3348HR provides 24-bit 48-channel
recording/playback by increasing the tape speed to 1.5 times that
of current 16-bit DASH machines. By employing this technique, it
can perform both 16-bit (at 30ips and 48kHz) and 24-bit (at 45ips
and 48kHz) recording/playback without changing the type of tape
used.
A maximum of 44 minutes of 24-bit 48-channel recording can be
achieved on a standard 14-inch reel of 1/2-inch tape at 44.1kHz.
So when using this encoding method and 1/2 inch tapes:
45ips = 48000Hz * 24bits * 48ch = 55,296,000bps
30ips = 48000Hz * 16bits * 48ch = 36,864,000bps

If tape width and speed are proportional to data rate then 1/4 inch at 15ips should be 9,216,000bps only, which can be 192000Hz * 24bits * 2ch.
 
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Wombat

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restorer-john

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Or a carpet snake

carpet snake.JPG
 

Wombat

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