Service Manual/Schematic Philips CD680

[danvee]

Hi,

I've just obtained a Philips CD680. It's in REALLY good shape, but it does need a little help sonically. I've modded many Magnavox models in the past, and the layout of this player is similar to the Maggie 471/2/3, but the mainboard is different, including a daughtercard for the analog outouts.
I've searched the 'net to the best of my ability and turned up nothing in the way of a service manual, or even much info at all on this player. It uses the venerable tda1541/saa7220 set.
If anyone here could help me, I'd very much appreciate it.

Thanks in advance,

Dan

[amc184]

I haven't seen the manual for this player around before, but most likely it's very similar to or the same as a few other Philips players. If you take a photo of the player's internals from above, I (or someone else here) should be able to find which manual will suit you best.

[danvee]

I should have thought of that---Thanks!

[SoNic_real_one]

Looks like my Sylvania CD1473 (that is actually a Philips CD473). TDA 1451, LM833... Yours has the headphone output on the right side, mine on the left (under the CD tray).

[danvee]

Thanks for the help!

Does your CD1473 have a remote volume control? The inverted board on this one has a pair of MC14051BCPs feeding an NE5532 to the L+R line level outputs. Looks like this would be part of a remote volume control setup.

Dan

[danvee]

My guess would be that the red connector carries the R+ L+ and ground to the board. That's another reason for wanting the schematics.
The CD473 daughterboard appears to be different from this. I've posted the image from the CD473 Service Manual as well.

[SoNic_real_one]

Yes, the board that is upside-down is the volume regulator with MC14051 and a NE5532 made by JRC (as a buffer). And yes, it has a remote that can control the output volume.
The one from the manual (that you posted) is the headphone regulator (has an separate buffer and an analog pot).
I have removed the LM833 from the main board and rolled some other OpAmps in that location. The best sound IMO was with LM4562.

[danvee]

Thanks!

I've had some pretty good luck with the 4562s as well, but they sound a bit "harsh" at times. I've been playing with the AD8620ARZs and those do well in my CDB650.
I'd really like to bypass all of that R/C volume circuitry and the extra op-amp, as I've no need for the R/C volume (and I don't have the remote, either).
I've also added an image of the "headphone board" from the CD473 S/M.
Maybe there are a few revisions not accounted for in the manual that I have.....

Dan

[SoNic_real_one]

Don't worry about the headphones board, it is not in the way.
The gray connector brings the audio from the mainboard to the volume reg - you can bypass that. Just pull the big, green 100uF capacitors out and use a shielded conductor between the empty holes. Or you can leave only one capacitor in place to block the eventual DC offset component...

Or, if you look on the mainboard, there is a area with empty places where was supposed to be a fixed volume output. You can "build" that one.

PS; There where more that 5 "revisions" for the CD473, mine is similar with the ones labeled 01r, 05r, 07r

[SoNic_real_one]

Something like this.