Philips CD951 • A DAC7 (TDA1547) vs TDA1541A R1 vs SM5872 story

[Malefoda]

Hi guys,

here I go with a CD-53 ars at the CD951's one
Before this, it was OEM output caps bypassed with MKS 1µF (well, won't be worse than dead elcaps!) and LM4562, 4.7µF after +/-15V regulators (yes 4.7!!!) are now Cerafine 100µF.

It was more balanced in frequencies than my CD-53 wich have clocks and regulated drivers and load of caps for now, CD-43 output stage but MKPs to RCAs.
CD-53 was more detailled, a bit more bass and that's it. So in this state the 951 was the one to live with, CD-53 wanted more work.

But now it's another story, DOS from Ray's site ( check the CD63 & 67 thread ) for balanced voltage output DACs. It's a direct fit, and I also used my MKP/Russian Caps combo.
And well also fited in a dedicated 7805 with a LPF on its supply at the SAA7350.

Guess what? Wow! I've the "rediscover my discs" deases again! It's wider, deeper, cleaner, bottom is just far better than CD-53, it's so well balanced, not bright, not dark.
Voices have no fat on lowers like CD-53, it's already very good.

So now I'm a bit disapointed, CD-53 need so much work to sing ( but with the DOS it will ), this one already sings high end, it might be a wonder with clock and clean PSUs...

This could be heaven or this could be hell...
If I mod it, how I'll get back on my CD-53, cost of a CDM9, have to invest in 3 players... if one is sold then only 2... what should I do...
If only there was a garantee that money invested (and work!) will be back... it's a risky job there. Risk on 3 players...
Damn, as we say in french let's wait tomorrow as " la nuit porte conseil "...

Sell it... but I just can't kill the beast...

[mb]

Congratulations on the progress with the CD951. I have modded many CD950s, which I believe are almost identical to the 951, and results have been much better than anything I could achieve with the Marantz 63/67.

For coupling caps I remove them (bypass by wire) completely. They are not needed. Just check dc offset before using. Nothing beat a coupling cap like wire.

My mods were mostly before the LM4562 was introduced, and the most success was with LM6172. If I had to do a unit now, I would use the LM4562.

The bulk of the mods were power supply related. Schottky diodes throughout, Panasonic FM caps, and new separate regulated power to the analog section of the TDA1547. This was the trickiest, building up a small regulator boards and cutting off the original supply tracks, but it brings new life to the player.

[Malefoda]

Hi MB,
right now I don't use the player's analog stage anymore. It's a discrete stage and this does a lot of DC, anyway sound is so much imporved that even with coupling caps it's better than opamp based output.
As for me my CD53 (same as 63) is very well modded (well beside the output stage is in the CD951... ) and sings quite nicely.
But I must admit the CD951 sings well for less modding job.

Matthieu

[Thomo]

Hi Matthieu, are you still using your TDA1547 based player? I've recently switched back to mine and am just starting to mod it properly again.

Cheers,

Lee.

[Malefoda]

Hi Lee,

no, it's an ended story now, my CD-43 does it duty well
Anyway it was very good even if the needed dedicated PSUs are close to a nighmare!

[Thomo]

That's a shame, but I'm glad you're happy with your current cdp.

And yes, that tda1547 does have lots of psu rails doesn't it? lol.

Cheers, Lee.

[Thomo]

What made you switch back to the cd43? Did you not solve the intermittent problems you mentioned earlier in the thread?

Lee.

[Malefoda]

CDM9 was defo dead.