From: scott@psy.uwa.oz.au (Scott Fisher)
Newsgroups: rec.audio
Subject: Sony Scoopman NT-1 was Re: DAT, DCC and MD
Date: 28 Jan 1993 02:57:30 GMT
Organization: The University of Western Australia
NNTP-Posting-Host: wapsy.psy.uwa.oz.au

graeme@labtam.labtam.oz.au (Graeme Gill) writes:

>In article <C1EuKp.3wq@fulcrum.co.uk>, igb@fulcrum.co.uk (Ian G Batten) writes:
>|>Au contraire, VCR technology is expensive.  Cheap, nasty cassette
>|>players cost ten pounds.  DCC's only expense over a grungy cassette
>|>mechanism is the head, which isn't a moving part but is more complex
>|>than a standard analogue head.  But in the digital domain problems like
>|>wow and flutter can be addressed by buffering, and high mechanical
>|>accuracy is what costs money.

>	I came across an article recently from Sony in which they describe
>a play only DAT mechanism that uses a non-tracking technique combined with
>memory buffering. By "non-tracking" they mean that the play head doesn't 
>track the helical tracks but may read them at a slight angle, and may read
>the same track several times. As a result they don't need a fancy rotating
>head motor, and mechanical tolerances need not be as fine. They
>claim this design leads to a low cost, low power consumption mechanism
>that is very rugged. It is intended for car DAT players and walkermans.

I have the Feburary issue of Electronics Australia in front of me as I type.
It reviews the Sony NT-1 Scoopman...

Specs: (Test data..not factory claims)

Frequency Response: 10Hz - 14.5 kHz (+/- 0.1db)
                     2Hz - 14.6 kHz (=/-3dB)

Dynamic range:      75dB unweighted
                    80dB (A)

Channel Separation: 20Hz  = -80dB
                    1K    = -78dB
                    10kHz = -70dB

THD:
			Level	THD
			3.0V	0.12
			2.0V	0.10
		(0dB)	0.5V	0.09
			-2.0dB	0.07
			-4.0dB	0.06
			-6.0dB	0.05
			-10dB	0.03
			-20dB   0.04
			-30dB   Below noise 

The cassette dimensions are 30mm x 21mm x 5mm, the tape comes in 60, 90 and 120
minute lengths and is 2.5mm wide.  The tape has two sides. The machine will 
record for 7 hours on a single AA battery. It's stereo sampling at 32 kHz with 
12 bit non-linear quantisation.

The rotating head mechanism works something like this...

With a direct drive 4 head head drum of 14.8mm diameter the machine records on 
1/2 the tape width (2 sides remember) for a total track width of 1mm.

The NT in NT-1 stands for Non Tracking...basically the rotating head is pushed 
into the cassette shell (in the same way a convetional tape deck pushes it's
heat into the tape) and all the tape guides etc are built into the cassette.
Just imagine your compact cassette has a rotating head in place of the fixed
one it has now.  When the head pushes into the casette the tape is wrapped
around the drum.  The machine reads at 2X recording speed...this causes the
machine to read the same tracks twice on playback.  Each track (angled
stripe across the tape) contains 104 data blocks.

According to the reviewer the quality of recorded CD's was "astounding."
He suggested that he had a hard time picking the difference between the CD and 
the NT-1 recording (he did mention that he must be getting old :-)

Regards Scott
_______________________________________________________________________________
Scott Fisher [scott@psy.uwa.oz.au]  PH: Aus [61] Perth (09) Local (380 3272).                
                                                             _--_|\       N
Department of Psychology                                    /      \    W + E
University of Western Australia.      Perth [32S, 116E]-->  *_.--._/      S
Nedlands, 6009.  PERTH, W.A.                                      v       

Joy is a Jaguar XJ6 with a flat battery, a blown oil seal and an unsympathetic 
wife, 9km outside of a small remote town, 3:15am on a cold wet winters morning.
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