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Introduction
The SL-P10 is a now quite rare first generation CD player
that was produced by Technics in 1983 close on the heels of the
Sony CDP-101, a player that I have owned
since that time. In the old days of CD, I had a choice of the
Sony CDP-101, the Technics SL-P10 or a
Hitachi DA-1000. The only real reason that the Sony won me over was that it
had remote control, a feature not present on any other player at the time.
The SL-P10 would of course have been a much better match for my
Technics SE-A5 back then, but at least I
have one now!
SL-P10 Description
 On the outside, one thing stands out in the design of the SL-P10 and that is the
fact that the disc is played vertically. This is how the prototype Sony
player was and all first generation players were like this except the
Sony CDP-101 with a loading draw and the
early Phillips machines like the
CD-100 that were top loading like old Laservision video players. This makes it look
quite interesting as you can see the whole diameter of the disc spinning as it
plays and the loading & unloading sequence of the door is quite fun to watch,
much more interesting than a dull plastic tray sliding in & out!
Having said that, the sales guys at the time loved the remote on the Sony where
they could surprise curious browsers in the shop! On the
door itself there is a small red LED indicator that shows the location of the
laser or sled on the radius of the disc. It has a graduated scale printed on the
door that gets smaller as it goes to the right towards the edge of the disc.
So this represents the approximate physical time points on the disc where the
pickup head is with one large mark for every 10 minutes, and one small one for
every two minutes. As data is recorded in a spiral on a CD (Constant
Linear Velocity) with the data
being read at a linear rate, the disc spins quickly at the center (about 519
RPM) and more slowly towards the end (about 204 RPM) and the
pickup sled moves more slowly towards the edge of the disc and so the scale is
compressed. As well as this cute physical indicator, the SL-P10 has a
fantastic VFD display that is far superior to the
Sony CDP-101 or just about any other CD
player ever! The display is divided into five sections. The top
section displays time in a linear fashion, this time with a mark for every 5
minutes and a numbered mark every 10. That part of the display is static.
The second section under that is made up of bars, one for
every minute of
playing time passed. As each minute passes, another bar lights up building
up into a row of bars ending at the current play point. Also, the bar that
indicates the time of the final minute lights. So by looking at this and
the scale above, you can easily see how much of the disc has played, and how
much there is to go. Next under that is a third section. Here there
are similar bars but this time, one bar lights up to indicate the beginning point of
each track. In the fourth section there are bars again, this time each bar
representing a programmed point on the disc. Next under that is a standard
numerical display that shows the current track number and current playing time.
There is no time/lap button to change this part of the display to show remaining
like on a normal player, but who needs it with this super display that can be
seen clear across the room! Technics certainly splashed out a lot of money
for such a display in those days! There are the usual buttons for repeat, search, stop,
play & pause but strangely there are no forward and back skip buttons common on
all other players. To go to a particular track you have to enter the track
number and press play. Then as the sled makes it's way to the required
location on the disc, the first row of bars expands or contracts in exact time
with the motion of the sled. Cool! Truly a beautiful piece of Technics equipment designed at a time when they could just do it how they wanted
and make it sound & look right! Click
here to see the user guide.
This really is the
SE-A5 of CD players!
Inside the SL-P10
The Technics SL-P10 CD player is pretty unique in its construction, in that it
is built like a tank! A heavy all
metal case like all high-end Technics
gear and a metal framework of internal construction. To look inside the
SL-P10 and the
Sony CDP-101 together, you could
easily believe that the SL-P10 was made years before the Sony if such a thing
was possible. The sled servo or
traverse servo as they used to call it is
built heavy and looks as though it would be just as at home if it were inside a
washing machine! The spindle motor is big with the platter being fixed on
with a hex Allan key and the bearing leaks more oil than my truck! The optical
assembly is more than three inches long with a cross- section of about 3/4 of an
inch and is made from an extruded black anodized aluminum casting which is
finely machined to accommodate the optical components which are clearly
assembled by hand. The door is operated by a heavy series of worm drives,
gears and belts and believe me, it is quite an effort just to get the door of to
see what's inside! The main PC board at the bottom of the player has two large daughter boards on the right side and there are 7 other smaller daughter
boards too. The right most daughter board looks like it has most of the
digital circuits and the big chips there with their gold legs look like something from Star Trek! Another board fits on top and there are two large boards
at the front behind the display. All of this is connected together by streams of thin
individual wires and there are numerous wire straps snaking around on all the
boards. I can also see about 20 or so small trim pots that no doubt need
to be adjusted "just-so" for it to work. To be frank, it's a real mess in there
and I don't think it could take too much vibration! Having said that, it
is certainly strong. There are
12 key LSI chips in the design and as well as that there are numerous other
74LS series logic gate chips all over.
Optical Pickup Assembly
As
the construction of the optical pickup is so large and hand made, I thought it
would be nice to disassemble one that I have that is not working so
as to record the inner details. While a description of how a CD player
works is outside the scope of this page, I'll go through all the components of
the pickup. In the marketing materials for the SL-P10, Technics had a nice
diagram (upper left) that showed all the components. In the service
manual, there is the diagram (lower right) that this probably came from with a
little more detail. I just added the red to more clearly indicate the path
of the laser light. With the pickup out of the player, the three main
components can be seen bolted onto the outer casing of the extruded aluminum
case, the laser diode at one end, the photo detector at the other and the pickup
focus lens on the side.



More coming soon...
Service Data

| Chip No |
Chip Type |
Description |
| IC101 |
AN7673 |
Drive Matrix |
| IC104 |
AN7674 |
Trick Play Control |
| IC105 / 106 |
AN7671 |
Actuator Drive |
| IC111 |
MN1400 |
CPU / Microcontroller |
| IC110 |
AN7676 |
Stepper Motor Driver |
| IC251 |
AN7670 |
Head Amplifier |
| IC301 |
AN6635 |
Motor Driver |
| IC302 |
AN660 |
Servo Controller |
| IC501 |
MN1542 |
Display Controller |
| IC701 |
MN6611 |
EFM Demodulator |
| IC702 |
MN6612 |
CIRC Controller |
| IC703 |
MN6613 |
Error Correction |
| IC704 |
AN6610 |
Servo Controller |
| IC705 |
MN1564 |
Microcontroller CPU |
| IC801 |
AN6608 |
D/A Converter |
|
| Board Descriptions (click for pictures) |
| 01 |
Optical servo, audio and constant voltage |
| 02 |
Digital |
| 03 |
Head amplifier |
| 04 |
Display |
| 05 |
Keyboard |
| 06 |
Tracking hold and spindle motor control |
| 07 |
Power fuse and filter |
| 08 |
Waveform shaping and PLL |
| 09 |
Drop-out control |
|
Click
here to see the complete adjustment manual for the Technics SL-P10.
More coming soon...
Pictures

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