SUPER Early Access: A Tale of 2 CD players

The headphone output is normally tapped off the main line-level signal inside the player and amplified with its own little chip. More likely either a) some marketing dude in Sony decided this was the least used feature or b) some bean-counter decided that omitting the amplifier chip, socket and volume pot would make a worthwhile saving in cost (or both) ;-)

Gordo

Wow. So, my parents STILL have their Sony stereo setup. I remember vividly thinking that it was cool that you could put disks into the CD changer while it was still playing a disk. Over the years however, the components to the setup have slowly died. The CD changer was the first to go (I think my parents are on the 3rd or 4th at this point) and I just recently found the tape player to have stopped working (ironically with a Smashing Pumpkins tape in it haha) and finally the speakers blew out at some point (probably a product of age mixed with having 4 teenage boys in the house). I had tossed around the idea of rebuilding the system and finding original components, but finding working ones in this day in age might be a little more than I feel like dealing with for the time being. Like your family, mine is very big into music, and the Sony stereo has been in near constant use for as long as I can remember. Cheers :)

Ginger Spice

Jeez Sony had how many engineers dedicated to coming up with these machines?

Phillip Cosgrove

Damn, you're onto something there.

Ketafuki

That thumbnail makes a good profile picture! Great smile :D

This is super neat! Like an alpha or beta release, but for da youtubes =D

Ketafuki

as it a 'seperates' unit, did people just plug headphones into their amp? so ended up redundant on the player

Ben O'Hara

I wonder if the person who designed the non-exchange mechanism went "D'oh" when they saw the new style. If they spent a few more dollars, they could've put a CD detector under each tray, no rotate- routine required.

Wim

Yeah the 225 probably has the same position sensor. I was able to move the tray by hand rather easily (a flaw in its original drive design I guess) and as soon as I pressed disc skip, it realized it was out of position and did the shimmy to correct itself. I realize that the 235 needs to have the tray stationary when it's closing with a disc playing the ex-change mode, but it shouldn't matter for general loading and and unloading. I suspect the later player that my parents have operates with this assumption. Spin while loading if not playing a disc, don't spin if a disc is in play. Perhaps it was just simpler for the programming to not differ from mode to mode, so they always have the tray stationary when closing. And thanks for the pics! I plan on keeping the 235 intact so it's neat to see what's there.

Technology Connections

the 235 has to keep track of which slot the spinning CD came from, and ensure that slot is in the correct position when the tray closes, otherwise the mechanism could push a CD around if there was one in that position. The 225 doesn't have to care about this because all the CDs are in their slots when it ejects, so it doesn't have any state it needs to restore when it closes, and can go right to the disc you just put in (without having to put the old disc back first). Maybe the addition of the IR disc sensor is related, so it can check that a slot is empty before it closes and tries to put a disc there? I took apart my CDP-245 (September 1994), it seems to be the same as the 235. Here's a pic of the IR sensor with the tray off: <a href="https://www.dropbox.com/s/w48h6uxzclpzllj/2018-09-09%2015.30.58.jpg?dl=0" rel="nofollow noopener" target="_blank">https://www.dropbox.com/s/w48h6uxzclpzllj/2018-09-09%2015.30.58.jpg?dl=0</a> There is also a second IR sensor for detecting the position of the rotating tray: <a href="https://www.dropbox.com/s/6smvcpayag07une/2018-09-09%2015.32.56.jpg?dl=0" rel="nofollow noopener" target="_blank">https://www.dropbox.com/s/6smvcpayag07une/2018-09-09%2015.32.56.jpg?dl=0</a> (you can also see how the tray rotation is driven). The tray has an encoding on it <a href="https://www.dropbox.com/s/lc7o354v2z5n8vp/2018-09-09%2015.33.06.jpg?dl=0." rel="nofollow noopener" target="_blank">https://www.dropbox.com/s/lc7o354v2z5n8vp/2018-09-09%2015.33.06.jpg?dl=0.</a> putting the tray back in completely different position than it was when I took it out, the player was still able to figure out which slot was which. My guess is the 225 has this sort of encoder too.

adcurtin

1 guy 2 cd changers

Lorenzo Novara

Well that's going in the description! (I actually had that in the first upload--this was a re-upload due to a render issue and I forgot!)

Technology Connections

It was the best of times, it was the worst of times. A tale of two CDs. :D

adcurtin

I assume the thumbnail features the moment just before they put the straight jacket on you and took you away.

Kyle Olson

It's a very uneducated guess, but what if it needed some kind of common resource (i.e. main IC I/O wire) that was taken from the headphone jack and repurposed for the new disc detection system in the newer model?

rozboris

You can post a link, and a startling one at that!

Technology Connections

Not sure if I can post a link on here, but that wonderful auto-thumbnail seemed very familiar. An idea started SHINING out in my mind. HERE it comes, via some really naff MS Paint skills! I'm not sure Jack Nicholson would approve... <a href="https://ibb.co/jDuxs9" rel="nofollow noopener" target="_blank">https://ibb.co/jDuxs9</a>

Gavin Rea-Davies