Marantz CD273

[thirteeneast]

Don't think ive ever posted here before but have read the board for quite some time.

So first of all hello,

I've got a few CD Players but the one I use most is a CD273, mainly because I like the Size and it plays well.

Is anything worth changing, Any recommendations?
Op amps already able to be swapped and most caps have been changed due to its age, But any worthy gains that can be achieved?.

Many thanks.

 

[thirteeneast]

For example would it benefit from a stable temperature compensated crystal?
such as 11.2896Mhz 11.289600Mhz TCXO 0.1ppm Ultra precision Golden Oscillator CLOCK power supply high precision temperature compensation|Amplifier| - AliExpress

 

[StewartH83]

I'd start by replacing those blue Philips electrolytic caps as they're usually low in capacitance, the 33uF on the circuit board under the transport can give issues towards the end of discs. You can use common radial types as replacements.

Also, use bi-polar caps or even film caps on the output of the Opamps.

Install sockets for Opamps and try different ones.

As mentioned, a clock upgrade has decent improvements

 

[thirteeneast]

Hello Stewart,

Many thanks for that, I'll work my way through the rest of those caps, the ones on the transport are all replaced just the main board and one at the front of the display left.

At the moment it has OPA2134 as the IC sockets id already done.
Would any of these be a prefered match?

Also as far as the clock is concerned any advise on either of these? (the last two requiring TCXO)

11.2896Mhz 11.289600Mhz TCXO 0.1ppm Ultra precision Golden Oscillator CLOCK power supply high precision temperature compensation|Amplifier| - AliExpress


Free ship Function clock precise regulated power supply board compatible with TCXO OCXO frequency divider board|supply board|board boardboard power supply - AliExpress

high stability Clock oscillator buffer module TCXO oscillator power board to CD player DAC AUDIO|dac audio|audio dac boarddac audio board - AliExpress

Many thanks for your help.

 

[StewartH83]

Try the NE5532 and LM833 first. These will go straight in as they're dual bipolar Opamps. Check the datasheets for the others to see if they're the same.

Those clocks seem ok, check you have the correct frequency as the one you're replacing, I think they're are fine but just to make sure. Keep the wires as short as you can

Have you tried bipolar caps on the output of the Opamps? Also, good practice to put a ceramic capacitor, around 0.1uF (104) across the DC supply pins of the Opamps

 

[thirteeneast]

Hi Stewart,

I'll have a browse at the datasheets thanks.
My players clock is 11.2896 so thats what ive ordered, I will be able to mount it extremely close to the original position so should be able to keep the cable very short.
Im waiting for some Nichicon MUSE 47uf caps I ordered last week for the output caps but hoping I can find some polyester caps amongst odds and sods laying around.

"Any prefered value for these output caps"?

I will also add the ceramic across pin 4,8 of the op amps as i've plenty of those around, thanks for the tip.

I was thinking to bypass the SAA7020 but i'm not convinced (any thoughts)
Thanks for all the help.

 

[N101N]

Bypassing the SAA7020 could be the most significant improvement.

 

[thirteeneast]

Hi,

I had read its preferred to give the SAA7020 its own dedicated power supply?
Tda1541 Nos Mod Pro's vs Con's | pink fish media
I think the comment here "trying to sort the wheat from the chaff" is exactly where I am at the moment.
Which of the non oversampling mods would you recommend? just wire bypass or using 74HC175N

 

[N101N]

According to a description:

1. Locate the "LEG 1" on the underside of 1541 and 7220 chips
2. On 7220 cut both traces as close as possible to legs 15 and 16
3. On 1541 cut trace as close as pos on leg 1
4. Using a thin wire connect the 1541 and 7220 : leg 1 to 1, 2 to 2, and 3 to 3.
5. Connect the 7220 leg 23 to the de-modulator chip 7210 leg 11. If the mute trick does not work, you must float (isolate) the leg 11 on SAA7210 before connecting it to SAA7220P 's leg 23.

 

[thirteeneast]

Hi,
Yes thanks I'd seen that on lampizator as well, But I was referring too which method is preferred and looking for personal experiences with non oversampling mods rather than the procedure of doing it.

Have you experienced the comparison?

Thanks

 

[rfbrw]

I'd tell you NOS sounds like sh1t but I'm just one data point. The only way to know is to try it.

 

[percival007]

And here's an opinion that NOS sounds wonderful.
But as above, it is a subjective thing I think so only you can decide.

It's easy to do on that Player and therefore really easy to put back if you don't like it.

P.

 

[N101N]

thirteeneast,
that should be the preferred method to carry out the nonoversampling modification and to gain personal experiences.

I'd tell you NOS sounds like sh1t but I'm just one data point.

You may also have bad taste.

 

[rfbrw]

You may also have bad taste.

Maybe. Maybe not. But it could be worse. I could be you and that would be a life sentence.

 

[N101N]

It was a mistake to implement oversampling in this technique (that is qualitatively unsurpassed up to the present time).

 

[thirteeneast]

And here's an opinion that NOS sounds wonderful.
But as above, it is a subjective thing I think so only you can decide.

It's easy to do on that Player and therefore really easy to put back if you don't like it.

P.

I'm sure I have a 24 pin socket around, making the reversal even easier.
but i'll leave it till last to see what difference it makes rather than doing it in the middle.

Appreciate the opinions though, Opinions are subjective and Im normally outside the box, so i'm happy with subjective.

thanks again.

 

[StewartH83]

How are you getting on?
Interesting about the non oversampling. I may have to give it a go on my Marantz CD75.
Also want to see how you go on with the clock upgrade as I may do that too.
I'm guessing you have no headphones output on the player?

 

[StewartH83]

I believe increasing the caps to the bottom right can have a good improvement. I'll be trying that. They're 47uF on mine, may go upto 220uF.

I have two caps left in the power supply as they tested good. The Elna's around the Opamps I've not removed yet but I'd need smaller caps there if I'm to fit some sockets to try other Opamps. I'll try some LM833, LM4562 and some Burr Brown's when they arrive.

The Opamp output caps were two 100uF's back to back = 50uF but they tested the worst in the unit. I did try some 10uF Nichicon Muse BP but found some 22uF BP Cerefines I pulled from an old Denon player sounded better.

Also thinking of removing the muting transistors 🤔

 

[Lampie519]

Non oversampling is better then most digital filters (as used in most players). Once you heard oversampling done correctly then there is no way back.

 

[thirteeneast]

Many thanks for all the replies,

Not had chance to do much more as I've been busy with work work no fun.

Ive parts on order that i'm waiting on like a 74HC but i'll be sure to keep the progress updated.

Non oversampling is better then most digital filters (as used in most players). Once you heard oversampling done correctly then there is no way back

Which method would you consider properly done?

Many thanks.