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Interesting fact about the world's first CD player

restorer-john

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I saw something quite interesting whilst poring over the world's first CD player, the Sony CDP-101 schematic:

1577692209403.png


CX-193. Pin 19 "strobo". And a bunch of unused (tied to Gnd) functions on the Disc Motor Servo IC. What were they for?

The CX-193 is a very early IC number from Sony and all the player ICs are in the 4 digits (CX-xxxx)

Was it actually a dedicated Quartz Lock DD turntable IC they used for the world's first CD player's BSL motor drive? Hence the unused 'strobe' output?

Yes it was! I thought of a few Sony TTs with a single point PLL derived strobes, the PSX-50 and the PSX-70 from 1978/79. These guys with the nice PUA-xx arms:

1577692752224.png


1577692943041.png


PS-X70 Turntable:
1577692617708.png

PS-X50 Turntable:
1577693074042.png


Very cool adaption of an already existing Sony Turntable IC by Sony engineers. The RAM control IC (CX-7934) controls the CX-193 to speed up or slow down the disc to ensure the RAM buffer remains optimal.

Handy to know, if you need a CX-193 for a PS-X50 or 70, as they are inside old Sony CDP-101s or vice versa.
 
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restorer-john

restorer-john

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What you saying? With a mod or two you could play LPs on CDP-101?

You'd have to cut down the LPs to fit them in the CD player drawer and the play time would be, very, very short. In fact, it'd be mostly lead-out groove and label. Oh, and we'd need an arm and cartridge too.

I couldn't do it. Heitaro Nakajima (R.I.P.) would turn in his grave. ;)
 

JoachimStrobel

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You'd have to cut down the LPs to fit them in the CD player drawer and the play time would be, very, very short. In fact, it'd be mostly lead-out groove and label. Oh, and we'd need an arm and cartridge too.

I couldn't do it. Heitaro Nakajima (R.I.P.) would turn in his grave. ;)
Would it not be better to mount the laser-pickup on the arm and turn the Cd around? That would play longer, and I am sure there is a software piece to change the pitch afterwards.
 
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restorer-john

restorer-john

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Would it not be better to mount the laser-pickup on the arm and turn the Cd around? That would play longer, and I am sure there is a software piece to change the pitch afterwards.

OMG, you crack me up. :)

My "discovery" was only a component part, but nonetheless, you can imagine the TTs guys at Sony saying "hands off our PLL IC for your new fangled laser disc player". Although I believe it was H Nakajima who was head of Audio and Digital at that point and he had the patents for the BioTracer TT servo arms to his credit, so he probably got exactly what he wanted without question.
 
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Wombat

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OMG, you crack me up. :)

My "discovery" was only a component part, but nonetheless, you can imagine the TTs guys at Sony saying "hands off our PLL IC for your new fangled laser disc player". Although I believe it was H Nakajima who was head of Audio and Digital at that point and he had the patents for the BioTracer TT servo arms to his credit so he probably got what he wanted without question.

Do I have that chip in my PL L1000 T/T?
 

Wombat

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restorer-john

restorer-john

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Do I have that chip in my PL L1000 T/T?

Here you go Wombat, it was PA-xxxx ICs

1577703528623.png



If you have the PLL 1000a, then it's a different story altogether. I think I have a spare motor here someplace if you need one...
 
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restorer-john

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My Sony PS-8750 may have it?

No, your beautiful PS-8750 is pretty much totally discrete. It's a lovely TT and several years before the TTs I am discussing.
 
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