Hello to all
I also have a '48' and i found that all the blue philips axial cap were way out of spec! So i replace them with fresh caps and put them under the pcb as on the pic above from andreas.
Also the 3r3 are fusible rezistors and used as protection againt power supply!
So you can remove them and put a 7805 reg for each supply (analog, digital, ref)
Dimitrios.
I also have a '48' and i found that all the blue philips axial cap were way out of spec! So i replace them with fresh caps and put them under the pcb as on the pic above from andreas.
Also the 3r3 are fusible rezistors and used as protection againt power supply!
So you can remove them and put a 7805 reg for each supply (analog, digital, ref)
Dimitrios.
Once I'm happy that a power supply is working properly I tend to remove these fuse resistors, might be more dangerous but it's never caused me an issue yet.
If the shinkohs aren't fusible then they don't provide any protection anyway and a wire link will sound better.
REgards
Pete
Hello to you Dimitrios!
Are you sure about that ?
The 3R3 resistors I refer to take the 5 volt supply to the analogue, digital and i/v internal op amps of the dac chip and are very close to the chip. They just look like ordinary resistors - so if you are correct I'm very glad you pointed that out.
It does not refer to this in the service manual either.
Can I really remove them and just feed clean 5v straight into the dac chip?
I'd like to do that but only if it's safe - I'm also sure that Pete who posts here and who has a similar 1549 based cd player mentioned fusible resistors but I was unsure what he meant if I'm honest.
I already have smoothed and regulated 5v supply to the analogue, digital and i/v op amps and they even have their own transformer ( see my pics ) so power to the dac chip is very strong. I feed the new 5v x 3 straight to the 3R3 x 3 resistors which then carry it to the dac chip.
Thank you Dimitrios - this has been very helpful and will prevent me doing something bad. I've worked hard on this and don't want to damage it now !!
Are you sure about that ?
The 3R3 resistors I refer to take the 5 volt supply to the analogue, digital and i/v internal op amps of the dac chip and are very close to the chip. They just look like ordinary resistors - so if you are correct I'm very glad you pointed that out.
It does not refer to this in the service manual either.
Can I really remove them and just feed clean 5v straight into the dac chip?
I'd like to do that but only if it's safe - I'm also sure that Pete who posts here and who has a similar 1549 based cd player mentioned fusible resistors but I was unsure what he meant if I'm honest.
I already have smoothed and regulated 5v supply to the analogue, digital and i/v op amps and they even have their own transformer ( see my pics ) so power to the dac chip is very strong. I feed the new 5v x 3 straight to the 3R3 x 3 resistors which then carry it to the dac chip.
Thank you Dimitrios - this has been very helpful and will prevent me doing something bad. I've worked hard on this and don't want to damage it now !!
Blimey.....you are here too Pete !!
Thanks for heads up - and what a headache this is !
The new power and regulation is firing straight into these resistors and everything works.
If you were me....what would you do ?
Right....wire links it is then.
I'm confident in the regulators enough to do it.
I've just read the service manual again and all I see is a triangle with an exclamation mark inside it - adjacent to the 3R3 resistors in the drawings.
Nothing else refers to them being fusible unless that sign means fusible resistors does it ?
It doesn't matter now anyway but thanks must go to Philips for the clarity of their manuals....haha
Much appreciated
Andrew
I'm confident in the regulators enough to do it.
I've just read the service manual again and all I see is a triangle with an exclamation mark inside it - adjacent to the 3R3 resistors in the drawings.
Nothing else refers to them being fusible unless that sign means fusible resistors does it ?
It doesn't matter now anyway but thanks must go to Philips for the clarity of their manuals....haha
Much appreciated
Andrew
Hello again!
Yes these are fusible resistors and are fisicaly biger than the rest of the resistors! They are a bit grey!
These are in almost every cd from philips/marantz of that era and if you are confident with the power supply you can take it out!
Also don't forget to verify the axia philips caps!!
Yes these are fusible resistors and are fisicaly biger than the rest of the resistors! They are a bit grey!
These are in almost every cd from philips/marantz of that era and if you are confident with the power supply you can take it out!
Also don't forget to verify the axia philips caps!!
I've got tants over all the old Philips axials so I'l leave them as they are.
I forgot I'd done that and it also explained where they all were when I was looking for some yesterday....
Anyway I'm in and it's stripped down to the green board again
I've got a proper bc547 based teddy reg for the tda 1301 and a 7805ct reg for the saa7345 + tant and bypass cap.
Wires are twisted ( + ve and gnd ) and I'm almost there.
Wire to snip, trace to cut and then put it all back together again.
I've got to say I'm unusually nervous and I've come in from the cellar to have a cup of tea.
Oh...and the cellar is a room under the house which is my secret soldering place. I live on a hill hence the cellar existing.
It's NOT a giant Mansion with a wine cellar...hahaha
I forgot I'd done that and it also explained where they all were when I was looking for some yesterday....
Anyway I'm in and it's stripped down to the green board again
I've got a proper bc547 based teddy reg for the tda 1301 and a 7805ct reg for the saa7345 + tant and bypass cap.
Wires are twisted ( + ve and gnd ) and I'm almost there.
Wire to snip, trace to cut and then put it all back together again.
I've got to say I'm unusually nervous and I've come in from the cellar to have a cup of tea.
Oh...and the cellar is a room under the house which is my secret soldering place. I live on a hill hence the cellar existing.
It's NOT a giant Mansion with a wine cellar...hahaha
It's all in...it works and sounds VERY VERY nice indeed.
It's almost like it's playing slower but it's not....it's like I let a brake off or something.
It reads discs faster and just get's going quicker - brilliant !!
Metallic resonances, decay and instrument timbres are super clear and etched.
I love it - it's done something excellent and really worthwhile.
The power and scale across the room is the same which I like but it's cleaned it all up in a way that is reminiscent of the old SAA7220 getting it's own supply.
Maybe the clock feed is now cleaner and that's working better too ?
I'm shocked and delighted with the whole thing.
Thanks Andreas - brilliant tips, advice and pictures
It's almost like it's playing slower but it's not....it's like I let a brake off or something.
It reads discs faster and just get's going quicker - brilliant !!
Metallic resonances, decay and instrument timbres are super clear and etched.
I love it - it's done something excellent and really worthwhile.
The power and scale across the room is the same which I like but it's cleaned it all up in a way that is reminiscent of the old SAA7220 getting it's own supply.
Maybe the clock feed is now cleaner and that's working better too ?
I'm shocked and delighted with the whole thing.
Thanks Andreas - brilliant tips, advice and pictures
Nice job Andrew!! I like you got it further by mounting special regulators !!
It is a real upgrade for all players where I tried something like that.
I'm wondering what are those blue tubes at your laser mechanism assie? Are they something like suspension pods or..?
Cheers and happy audio sessions!!
I reduced the resolution of the camera...now it works !
I guess suspension pods is a great name for them - yes that's what they are doing but it's a temporary measure while I build my new case.
The player sounds so much nicer now - smoother and full of body.
I can't thank you enough Andreas.
So to you....did you get your external i/v boards working yet or test them ?
Andrew
Attachments
One from the underside....you can see the twisted pair going to the regulator, the orange tant and blue bypass cap.
The red tants are across the original philips axials only.
I did not take out the fusible 3R3 resistors this time - but I will eventually.
I was too keen to do the regs today.
The red tants are across the original philips axials only.
I did not take out the fusible 3R3 resistors this time - but I will eventually.
I was too keen to do the regs today.
Attachments
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