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!
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...
Click here to see the complete adjustment manual for the Technics SL-P10. More coming soon...