Hi all,
Nobody seems to have written an awful lot about this decent old (1986 design) Philips model, so I will.
I bought a CD650 via Ebay for about £10 or so a while back. I can't remember why I bought it but as my main cd player is out of action at the moment I've been listening to it.
It uses the famous TDA1541 DAC and has the immediately familiar character of solid, chunky, warm goodness heard in other TDA1541 designs. The only problem is a lack of detail, a slightly woolly bass and very poor treble.
I popped the lid last night and had a look inside. In particular I noticed:
* TDA1541 PSU lines are decoupled by tiny 47u caps
* Op-amps are NE5532
* Op-amp psu caps are more of the same 47u Nichicon poop
* Signal goes through electrolytics and muting transistors
* The chassis is plastic
I warmed my iron, cleaned off some of the dust and had an initial tinker.
I made the following changes:
* -15V decoupling cap on DAC changed to 2200uF / 25V Panasonic FC
* -5V decoupling cap on DAC changed to 4700uF / 6V Pana FC
* +5V decoupling cap on DAC changed to 220uF / 35V Elna Cerafine
* DC blocking / signal caps cut out and shorted with a solder blob
This has livened the player up a lot. The bass is tighter, the treble less dirty and veiled, imaging is better and the soundstage is more layered. The good qualities of the player don't appear to have been adversely affected.
More to come soon.
Simon
Nobody seems to have written an awful lot about this decent old (1986 design) Philips model, so I will.
I bought a CD650 via Ebay for about £10 or so a while back. I can't remember why I bought it but as my main cd player is out of action at the moment I've been listening to it.
It uses the famous TDA1541 DAC and has the immediately familiar character of solid, chunky, warm goodness heard in other TDA1541 designs. The only problem is a lack of detail, a slightly woolly bass and very poor treble.
I popped the lid last night and had a look inside. In particular I noticed:
* TDA1541 PSU lines are decoupled by tiny 47u caps
* Op-amps are NE5532
* Op-amp psu caps are more of the same 47u Nichicon poop
* Signal goes through electrolytics and muting transistors
* The chassis is plastic
I warmed my iron, cleaned off some of the dust and had an initial tinker.
I made the following changes:
* -15V decoupling cap on DAC changed to 2200uF / 25V Panasonic FC
* -5V decoupling cap on DAC changed to 4700uF / 6V Pana FC
* +5V decoupling cap on DAC changed to 220uF / 35V Elna Cerafine
* DC blocking / signal caps cut out and shorted with a solder blob
This has livened the player up a lot. The bass is tighter, the treble less dirty and veiled, imaging is better and the soundstage is more layered. The good qualities of the player don't appear to have been adversely affected.
More to come soon.
Simon
The to-do list after having a little look at it and chat with others about models using the same or similar chipset:
* replace opamps with DIP sockets (probably to use LM4562 or similar)
* change opamp caps to Rubycon ZA, BG standard or similar
* shield the processor and digital filter chips (maybe others?)
* feed the digital filter/decoder chip with its own regulator
* change PSU diodes to schottky type
* place player on wooden cones and install damping
* install Sercal C1 clock in place of 11.2Mhz crystal
* renew most electrolytics
To take it all the way:
* Sercal S Power regulators everwhere
* consider NOS connection and/or chip stacking?!
* new power supplies with transformers
* S1 or S2 (single or double crown) DAC
I don't think I'll take this one too far as the thing's quite ugly and plastic. A more worthy TDA1541 player is the Marantz CD94 in my opinion. Modified, those are terrific. Not terrible as standard, and not very ugly.
Simon
* replace opamps with DIP sockets (probably to use LM4562 or similar)
* change opamp caps to Rubycon ZA, BG standard or similar
* shield the processor and digital filter chips (maybe others?)
* feed the digital filter/decoder chip with its own regulator
* change PSU diodes to schottky type
* place player on wooden cones and install damping
* install Sercal C1 clock in place of 11.2Mhz crystal
* renew most electrolytics
To take it all the way:
* Sercal S Power regulators everwhere
* consider NOS connection and/or chip stacking?!
* new power supplies with transformers
* S1 or S2 (single or double crown) DAC
I don't think I'll take this one too far as the thing's quite ugly and plastic. A more worthy TDA1541 player is the Marantz CD94 in my opinion. Modified, those are terrific. Not terrible as standard, and not very ugly.
Simon
Hi Simon,
Welcome to the world of the TDA1541A
The NOS mod will alter the sound, but you might also do well if you keep the SAA7220, improve its power rail decoupling, and reclock the I2S before it enters the DAC. 4xOS is not a bad thing, per se, its just the chip that does it puta lot of jitter in the signal, and noise on the rails.
My 1541 has currently a simple IV (the single opamp IV with just a resistor and capacitor in the feedabck path as in the 1541 datasheet - don't skimp on that feedback cap, some faster opamps oscillate without it) followed by the passive filter Ray used on his CD63. I did try a discrete IV stage, but I'm yet to get it working. As far as I'm aware, the discrete IV for the CD63 won't work as the output of that DAC is voltage not current based.
There's also stuff you can do to alter the voltage levels of the I2S into the 1541, to reduce noise going into it
You'll enjoy the 1541, its a very different DAC to what you're used to. I found it was easy to get a good sound out of it, with relatively little effort.
Improved regulation will help, and many believe increasing the decoupling caps for the most significant bits (can't remember the pins) to about 1 or 2 uF.
Oh, and, I don't think you can easily stack them. They all need their own decoupling capacitors.
AND, might be worth searching for DEM reclocking. I tried it, and didn't have much luck, but some have had great results.
There's quite a few threads about on this (one hilarious one where I fail to understand simple electronics trying to go 4x OS) so have a search.
Send us some photos of what you've done.
Cheers,
Phil
Welcome to the world of the TDA1541A
The NOS mod will alter the sound, but you might also do well if you keep the SAA7220, improve its power rail decoupling, and reclock the I2S before it enters the DAC. 4xOS is not a bad thing, per se, its just the chip that does it puta lot of jitter in the signal, and noise on the rails.
My 1541 has currently a simple IV (the single opamp IV with just a resistor and capacitor in the feedabck path as in the 1541 datasheet - don't skimp on that feedback cap, some faster opamps oscillate without it) followed by the passive filter Ray used on his CD63. I did try a discrete IV stage, but I'm yet to get it working. As far as I'm aware, the discrete IV for the CD63 won't work as the output of that DAC is voltage not current based.
There's also stuff you can do to alter the voltage levels of the I2S into the 1541, to reduce noise going into it
You'll enjoy the 1541, its a very different DAC to what you're used to. I found it was easy to get a good sound out of it, with relatively little effort.
Improved regulation will help, and many believe increasing the decoupling caps for the most significant bits (can't remember the pins) to about 1 or 2 uF.
Oh, and, I don't think you can easily stack them. They all need their own decoupling capacitors.
AND, might be worth searching for DEM reclocking. I tried it, and didn't have much luck, but some have had great results.
There's quite a few threads about on this (one hilarious one where I fail to understand simple electronics
trying to go 4x OS) so have a search.Send us some photos of what you've done.
Cheers,
Phil
Thanks Phil,
Did we meet in Chesterfield last July? You've given me plenty to think about, thanks. I don't want to do anything too extravagant just yet, but a few simple mods first and see how it sings.
Some wooden cones arrived in the post from Hong Kong today - lovely! I'll get those put on tonight and I'll rustle up some pics as they're the fun part.
Cheers
Simon
Did we meet in Chesterfield last July? You've given me plenty to think about, thanks. I don't want to do anything too extravagant just yet, but a few simple mods first and see how it sings.
Some wooden cones arrived in the post from Hong Kong today - lovely! I'll get those put on tonight and I'll rustle up some pics as they're the fun part.
Cheers
Simon
philpoole said:
I thought the name was familiar. I keep killing my CD63.. but a good friend keeps fixing it. The CD650 has opened my eyes to a more appealing sonic character so I want to see how it can be taken further. Detail levels are currently a pathetic joke next to the HEAVILY modified CD63.
Any links to your TDA1541 project? I'd be very interested in reading about it!
Thanks,
Simon
I am busy to mod a CD880. Have been working a lot with CD304MK2, CD660 and CD640. The last two have the same decoderboard as your 650, the 650 has a sort of subpcb for a uController i think.
What i want to say is the CD640/50/60 have a good pcb layout in special the gnd screening is done properly. The CD880 has a more open gnd screen (you can shine a light through the board) i have a lot of interference problems now to solve after a kwak clock install. The 880 has an epoxy board, the 6## series paper-filled, and careful soldering is required
What i want to say is the CD640/50/60 have a good pcb layout in special the gnd screening is done properly. The CD880 has a more open gnd screen (you can shine a light through the board) i have a lot of interference problems now to solve after a kwak clock install. The 880 has an epoxy board, the 6## series paper-filled, and careful soldering is required
CD660 manual available here
http://71.203.202.83/pdf1/Electronics/Service_manuals/Other/Cd660.pdf
Andy
http://71.203.202.83/pdf1/Electronics/Service_manuals/Other/Cd660.pdf
Andy
Links...
Well, this one is quite out of date, but does show my CD940 used as a transport (with SPDIF disabled )
http://www.diyaudio.com/forums/showthread.php?s=&threadid=99920&highlight=
This one is the amusing one, where I completely fail to grasp (or I was perhaps too lazy to do it initially) that I needed to slave the transport to the clock in the DAC, but essentially details using the SAA7220 (which I suspect you have in a CD650) to make my DAC go 4xOS - and how it sounded.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=99652&perpage=25&highlight=&pagenumber=1
There's some other stuff kicking about, not many photos I'm afraid. I guess I'll have to take some more soon.
I'm currently trying to replace the SAA7220 with a PMD100 (using a schematic posted by Guido), so 8x OS and HDCD (although a little bit pointless with a 16 bit DAC). Its a bit hit and miss at the moment (I think I've got a bad joint somewhere), but first impressions are very promising.
Cheers,
Phil
Well, this one is quite out of date, but does show my CD940 used as a transport (with SPDIF disabled
)http://www.diyaudio.com/forums/showthread.php?s=&threadid=99920&highlight=
This one is the amusing one, where I completely fail to grasp (or I was perhaps too lazy to do it initially) that I needed to slave the transport to the clock in the DAC, but essentially details using the SAA7220 (which I suspect you have in a CD650) to make my DAC go 4xOS - and how it sounded.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=99652&perpage=25&highlight=&pagenumber=1
There's some other stuff kicking about, not many photos I'm afraid. I guess I'll have to take some more soon.
I'm currently trying to replace the SAA7220 with a PMD100 (using a schematic posted by Guido), so 8x OS and HDCD (although a little bit pointless with a 16 bit DAC). Its a bit hit and miss at the moment (I think I've got a bad joint somewhere), but first impressions are very promising.
Cheers,
Phil
I got one of those new. I agree it looks flimsy, but after 20 years or so it still works. Indestructable.
Search for pooge modifications, they can be applied to most philips. And DEM reclocking too.
There are 650 versions with and without sub pcb for processor.
If you really dive into the tda1541 specifics it gets complicated.
All the info is in the digital section, search.
DAC is the old non A, 7220 is the older A model. 7210 is there, but might havea different print M.... something. Three microprocessors in there also, bit much...
Put the powersupply on the filter pcb on a small pcb and you have space to put in other i/v's.
And yes, i've removed the 7220 and put in a pmd100
Re: Re: Philips CD650 mods
They come on sockets in this player so it won't be hard to do, just a case of sourcing those ICs... but I know someone that may be able to help.
It's hard to imagine a nicer sounding DAC than this. The player's not endowed with large detail levels just yet though.
Simon
musicomputer said:
They come on sockets in this player so it won't be hard to do, just a case of sourcing those ICs... but I know someone that may be able to help.
It's hard to imagine a nicer sounding DAC than this. The player's not endowed with large detail levels just yet though.
Simon