CD100 NON OVERSAMPLING

fralippo

Member
2006-01-29 10:46 am
Italy
Is it possible to configure the Philips CD100 for non oversampling? I can't find anything about on the internet. I tried the mod, but it doesn't work. I already did this to other 14bit, tda1540 based players succesfully. Maybe problem is due that my CD100 uses a M4300 ic in place of the usual SAA7000. Connections on PCB are the same as SAA7000 though.

Any idea? Thank you.
 

poynton

Member
2005-03-10 11:57 pm
UK
I do not understand why you would want to do this to this great player.

The oversampling was done on the TDA1540 chipset to bring it up to red book standard.
If you do a NOS conversion, you will lose 2 bits UNLESS you are replacing the TDA1540 with 16-bit DACs.

It will be an inferior sound, for sure.


Also, these players are now greatly sought after and go for over 200euros !


Andy


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fralippo

Member
2006-01-29 10:46 am
Italy
Hello Andy. Yes, I know, and I appreciate and understand your concern. This is an interesting player, historically also, and sounds really well as it is.

Did you ever listen to a TDA1540 in NOS? For me it's great! Before trying it, I also thought about the two bit less. And was a little worried, but sound is so good!

For years I used a TDA1541 based cd player, well modified. Low jitter clock, 3 separated power supplies (no LM317/78xx crap) for the DAC, output stages with no ICs, no feedback, very well supplied, DC coupled. NOS. A very good cd player!

About one year ago I bought a Revox B225 player (TDA1540). I removed oversampling, provided 6 nice power supplies to the DACs (a lot of Black Gate around), added a low jitter clock, replaced ALL electrolitic capacitors. Output stage is tube based (Aikido, 6N2P + 12SX7), done with very good components. Power supply is dual mono, tube rectified (UX-280 from the twenties), stabilized again by tubes, capacitors are PIO and MKP.

It sounds better than the good 1541 based player! No doubts.

Regards
Fabio
 
Ok, problem solved. I made a wrong connection. All is fine now!

Hi Fabio!
I have CD303 with not usual DAC board, i think the same as yours cd100 (m4300 chip instead of saa7000). I want to do NOS mod , but do not have idea what to do with m4300 (should i do switching to 14bit or not, i can't find any datasheet for this chip)

Can you share your experience how to do NOS with this chip set

Thank you in advance
Mikhail
 

fralippo

Member
2006-01-29 10:46 am
Italy
Hi Mikhail,

as I experienced the M4300 or SAA7000 share the same pinout. Here're usual instructions to get TDA1540 NOS:

remove TDA7030 completely, connect four 50/100 ohm resistors between:

pin 20 - pin 3
pin 17 - pin 10
pin 18 - pin 6
pin 21 - pin 7

- de-solder only pin 16 on SAA7000/M4300 with a solder wick and make sure pin 16 "floats", it does not make any contact the circuit board. (or simply cut the trace)
- solder a 1K resistor on top of SAA7000/M4300, between pin 16 and pin 18 (to put SAA7000 in 14 bit mode).

That's all. Post your impressions on sound after mod, please. I'm curious!

Regards
Fabio