You made me curious about those 2 and 4 pins. I have a TDA1541 and it has the connection between them. I will see if it is working the mod... It would be weird, but not impossible.
And, even if the datasheet for non-A shows internal DEM capacitor, my player has one on the outside too... Wonder why.
And, even if the datasheet for non-A shows internal DEM capacitor, my player has one on the outside too... Wonder why.
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In my CD960 (which is almost identical to a Marantz CD94 MKI) the std chip is a non A version.
The board links pins 2&4 and there is a 680pF dem cap.
Interestingly, the only difference between the CD960 and the CD94 is the A chip in the CD94.
My point being, the boards are identical for the A and non A.
I'd definately link pin 4 to GND for an A version (unless its an S version in which case i'd try it on sysclock).
I'd also build the DEM reclock (/4 inverted and non inverted) in place of the DEM cap (infact thats exactly what I've been doing for over a year now!!)
The board links pins 2&4 and there is a 680pF dem cap.
Interestingly, the only difference between the CD960 and the CD94 is the A chip in the CD94.
My point being, the boards are identical for the A and non A.
I'd definately link pin 4 to GND for an A version (unless its an S version in which case i'd try it on sysclock).
I'd also build the DEM reclock (/4 inverted and non inverted) in place of the DEM cap (infact thats exactly what I've been doing for over a year now!!)
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I don't have the 7220 chip in place but I'm feeding the external clock to 7210 through the 7220 clock out line.
I noticed that on a lot of the old Philips boards the clock out from the 7220 to the 7210 also has a link connection to the pin 2&4 of the 1541 chip. This is generally not connected with a link though.
I decided an experiment was in order and put the link in and removed the normal link to pins 2&4. Result? Silence. I did have continuity between 7220 and 1541.
Anyway I reconnected the original way and it worked again.
Regards
Pete
I noticed that on a lot of the old Philips boards the clock out from the 7220 to the 7210 also has a link connection to the pin 2&4 of the 1541 chip. This is generally not connected with a link though.
I decided an experiment was in order and put the link in and removed the normal link to pins 2&4. Result? Silence. I did have continuity between 7220 and 1541.
Anyway I reconnected the original way and it worked again.
Regards
Pete
CD650 Wiring harness problems
And here's the link - I forgot to include it on the last post:
Philips Magnavox CD650 CDB650 Restoration |
Regards
Menahem Yachad
And here's the link - I forgot to include it on the last post:
Philips Magnavox CD650 CDB650 Restoration |
Regards
Menahem Yachad
Hi Matthieu,
How did you find the fetishizator, I'm thinking of trying one myself. Did you build the simple one with just the BF245 or the one with the additional BS170 cathode follower?
Any advice?
Regards
Pete
Hi Pete and everyone.
I've been modifying an Arcam Alpha to a much higher level than I ever achieved with my CD650 (better caps, better supplies, more nice regs, better clock) and it is very good indeed! But there is something I got from the CD650 that has not been quite as present in the Alpha (same DAC, digital filter but maybe different decoder - Alpha uses 7310, is it 7210 in the CD650 et al?)
This thing I'm talking about is a certain creamy, warm sweetness. I think it's a change intrinsic to the player, not my mods, given at first my mods were almost identical.
It could be that the plastic chassis gives a superior character, it could be the TDA "decoupling" caps being ceramic have a certain cuddly charm, or the decoder chip being different (is it different? I forget). Or perhaps it's something else. Food for thought.
Simon
I've been modifying an Arcam Alpha to a much higher level than I ever achieved with my CD650 (better caps, better supplies, more nice regs, better clock) and it is very good indeed! But there is something I got from the CD650 that has not been quite as present in the Alpha (same DAC, digital filter but maybe different decoder - Alpha uses 7310, is it 7210 in the CD650 et al?)
This thing I'm talking about is a certain creamy, warm sweetness. I think it's a change intrinsic to the player, not my mods, given at first my mods were almost identical.
It could be that the plastic chassis gives a superior character, it could be the TDA "decoupling" caps being ceramic have a certain cuddly charm, or the decoder chip being different (is it different? I forget). Or perhaps it's something else. Food for thought.
Simon
I noted with interest the Fetishizator chap claims the sound character difference of the big-boy players like CD94 was due to the larger "decoupling" (wrong term hence "") caps around the DAC, though surely a crown DAC also provides some of the desirable sonic colour. I had previously put the great sweet treble and fluid sound of the '94 down to the superior CDM1 mechanism and discrete and huge servo section. I still don't know, maybe it is all of the above working together.
Hi Pete,
that was with no other TDA1541A player to compare, but went in instead of the OEM op amp set-up, so it's a JRC21** vs discrete fight, not that fair I went full circuit. Until now that my CD-43 has the CFPed DOS I held the CD-40 to sound better, full of life, and the Fetishizator was playing its part. No real amp at that time, but vs my slightly modded CD-43 it has realness and bass.
It was enough and worth it, even if I've never found the "link" between the tech commenting how bad it is designed and how good it sounded, again on a crappy amp and a bit better than average speakers.
Have parts ? Do it! Or the Pass D1?
that was with no other TDA1541A player to compare, but went in instead of the OEM op amp set-up, so it's a JRC21** vs discrete fight, not that fair
I went full circuit. Until now that my CD-43 has the CFPed DOS I held the CD-40 to sound better, full of life, and the Fetishizator was playing its part. No real amp at that time, but vs my slightly modded CD-43 it has realness and bass.It was enough and worth it, even if I've never found the "link" between the tech commenting how bad it is designed and how good it sounded, again on a crappy amp and a bit better than average speakers.
Have parts ? Do it! Or the Pass D1?
Well, I've built the fetishizator output twice now.
First time, nothing. Second time generally nothing but sometimes (sometimes when I poke it) a very distorted sound output.
It's such a simple circuit and I've dpouble checked it, I can't see how I've gone wrong with it.
Life's too short, back to the opamps.
Pete
First time, nothing. Second time generally nothing but sometimes (sometimes when I poke it) a very distorted sound output.
It's such a simple circuit and I've dpouble checked it, I can't see how I've gone wrong with it.
Life's too short, back to the opamps.
Pete
I just recently picked up a Magnavox CDB650 and I would like some guidance on modding it. I plan on using it as a source for my headphones. Specifically, I was wondering if the headphone output's Op-amp (JRC 4556) is worth upgrading, or if I should just save up the $50 or so that I'd need to build a CMoy amp.
Also, note that I'm 16 years old and that I don't have a job or much experience with modding so I probably can't afford the most premium components or do the more complicated mods yet.
Also, note that I'm 16 years old and that I don't have a job or much experience with modding so I probably can't afford the most premium components or do the more complicated mods yet.
Hi All, just digging up an old thread! I have dug my old Philips CD620 (similar to the 650?) out of the loft and plugged it back into my Sansui amp! Suffice to say the CD player is working fine (from what I can hear) but having stumbled across this modification thread, it makes me wonder ho wit could be improved after 20 years. I hope SimontY (diyAudio - View Profile: SimontY) is still around as he seems to have done the most mods on the 650, shame I'm no longer in York as it would have been great to meet and mod together! I now guess I have about 110 pages to read through to understand what is possible and to work out how easy it might be!
Hi ANdy, firstly thanks for your reply.
To answer:
Same value/voltage replacements. If not the same voltage then the next up but I don't think I did that on this occasion.
I've swapped out the CDM2/10 from a CD460 and have the same continuous spinning. Identical symptoms.
I've checked the voltages on the regulators, no issues there. Checked the supply voltage to the Saa7220, correct voltage there.
It's a bit tricky to test anything on the SAA7220 with the upside-down circuit with the flip-flop IC's mounted.
I've had the BC548 on the daughter board out, and it's fine on the component tester too.
There is laser output, and the head bobs up and down on both CDM2/10 assemblies. Laser current is correctly adjusted to 50mV within tolerance.
I think I read it's something to do with the clock, but I'm unsire where to go!
I haven't yet attempted to reflow or recap the two boards mounted on the back of the front panel, but dismounting and checking there could be my next effort.
Before the recap it was working when cold but warm it wasn't - bad solder joints. I'm carefully checking where I'm resolder, and where I'm reflowing with lead solder NOT modern solder, but the answer is eluding me!
Next up is to get the thing onto a Hantek DSO but that's going to be fun with the daughter board in the way!
Cheers
Greg
To answer:
Same value/voltage replacements. If not the same voltage then the next up but I don't think I did that on this occasion.
I've swapped out the CDM2/10 from a CD460 and have the same continuous spinning. Identical symptoms.
I've checked the voltages on the regulators, no issues there. Checked the supply voltage to the Saa7220, correct voltage there.
It's a bit tricky to test anything on the SAA7220 with the upside-down circuit with the flip-flop IC's mounted.
I've had the BC548 on the daughter board out, and it's fine on the component tester too.
There is laser output, and the head bobs up and down on both CDM2/10 assemblies. Laser current is correctly adjusted to 50mV within tolerance.
I think I read it's something to do with the clock, but I'm unsire where to go!
I haven't yet attempted to reflow or recap the two boards mounted on the back of the front panel, but dismounting and checking there could be my next effort.
Before the recap it was working when cold but warm it wasn't - bad solder joints. I'm carefully checking where I'm resolder, and where I'm reflowing with lead solder NOT modern solder, but the answer is eluding me!
Next up is to get the thing onto a Hantek DSO but that's going to be fun with the daughter board in the way!
Cheers
Greg