modified in june/  july 2008

The heaviest of the "TDA1541" range Sony CDP-555ESD on the outside seemed to me identical to my beloved CDP-337ESD but on close inspection I found that the PCB of CDP-555ESD is slightly different, with better regulation, better caps, only one DAC - better everything except that the DAC Philips TDA1541 is not doubled, but OTOH who said that two DACS are better than one?... The face-plate is (almost) identical BUT on close inspection it is totally different. Differences are a millimetre here and there, but this is a DIFFERENT thing. So looks can be deceiving. Funny why they did not use parts sharing in the production.


sony CDP555ESD

Sony CD Lampizator

The double backpack (camel?)

Similar thing applies to 337 versus 227. They look identical. Also the DAC seems the same - a paralleled TDA1541A (non-s)
BUT - first - the 337 is TWICE as heavy, due to double floor plate, metal chassis versus plastic, and twice as big transformer, and last but not least - a gigantic mechanism of 337 being Sony's top KSS190A. The 227's mechanism KSS151A is not bad either, but nothing prepared me for the KSS190A. It is so well made, that Accuphase used it in all their top models. Also Teacs V.R.D.S. uses sony mechanism with additional pressure plate. The mighty KSS190A is also similar to Kenwood's X9010 mechanism. Absolutely stunning masterpiece of engineering. Similar to CDM1 from Philips. The CDP-555ESD has two transformers - one for digital section, second for the analog. These trafos are so big, they have been mounted outside in a backpack fashion. This is just screaming "oh I have such beefy trafos I can't stand it !!!" My lampizator transformer adds to the list so we have THREE!


All in all - CDP-555ESD is the best Sony so far, one of the best TDA1541 players so far, and overall - one of the best players so farperiod. Sonically it looses only to the Wolfson DAC but only by a hair.
Arguably only Sony's own 557ESD may even be better by another hair. I am really impressed.

Non-oversampling or not ?

The CDP-555ESD has 4 times oversampling applied inside the chip that precedes the DAC  TDA1541, which is SONY CXD1088. We can identify the pins which carri I2S signals and bypass the chip with a bridge of 3 wires a'la Philips 7220p/B. BUT..... the sony chip is so small and it is SMD that the soldering is too difficulkt for me. Even with 10 x magnifying glass and a sharp tip I am unable to do it properly.
The tracks leading to and fro this SONY 1088 chip have no other points where I could tap to them. The only possible scenario is to solder to chip legs.
I thew the towel. Sorry.

KSS190A Mechanism ald laser

Sony KSS190A
This is the underside of the drop dead wonderful Sony KSS190A mechanism on Haal magnetic rails and everything is made of metal.

This is the bottom side of the beast. The red metal is not copper, it is copper-galvanized steel. Just like in Grundig 9009.

A glimpse of Sony laser underneath. The whole thing probably weights some 2 kilos.

This is a TRANSPARENT PCB of the SONY CDP-555esd - I never saw one like this before. Stunning look against the backlight.

Just look at these caps - Elna Duorex a size of a decent amplifier power supply. This CD player has more of them than I can count, and what I never saw before - they used shottky diodes for the bridge !
On the PCB of the
Sony CDP-555ESD every major cap has a regulator next to it. And every power consuming device has separate power regulation. What an overkill design !!!

The Philips DAC TDA1541

not A and not S1 DAC  is hidden underneath a ceramic red plate. I dunno what for - vibration? Heat dissipation? Temp stabilization? All three?
Note the copper heatsinks from voltage regulators just near the dac - just like the doctor ordered.
The clock is 16 meg, and it has anti-vibration black sock on it. All caps are premium Duorex again.

The top view of Sony CDP-555ESD

The output stage has separate power and regulation section. Shame we will leave it unused.

A comment: this player can be used without tubes. Just connect the first op-amp (a 20 leg Mitsubishi monster) to the output RCA's via MKP caps and the sound is SO GOOD IT IS BEYOND DESCRIPTION !!! POwer, purity, space, extension - all is there in spades. It left me in total disbelief. Getting rid of 3 more op-amps per channel cleans this CD in a fantastic way. The op-amp chip pinout is in the

The Philips DAC TDA1541 section close up - it has the 14 caps of premium quality (the red heads)  - no need to replace them. Although adding underneath in parallel some extra 220nF capacitance and increasing overall from 100nF to 320nF would be a nice icing on the cake.

lampizator, tube output stage on the Sony CDP-555ESD

Lampizator installation

cdp-555esd lampizator
Drilling the tube holes required some serious disassembly job ....

sony 555esd

New RCA's in the old holes and the tubes stick out a little bit to dissipate heat and to be replaceable without opening the CDP.


All power supply is hidden underneath the main PCB. A little tricky hob to be honest.


I basically repeat the most successful schematics:
The DAC Philips TDA1541 has current output called I-out which dictates that only very high gain tube must be used. IDEAL tube is the russian 6N2P (6H2pi) and even better - its super duper variant - EB (EV)

Do not, I repeat DO NOT try other tubes. This one mops the floor with the Siemens ECC801S.
Circuit SRPP, both cathode resistors 180-250  Ohms, ideally 200.
Conversion (for one DACTDA1541 ) is by 90 Ohm, (from 68 to 100 but NOT MORE)
Anode power 175 VDC (from 130 to 230 VDC)
Current is circa 1  mA.
Heaters are 350 mA per tube by 6,3V DC (do not use AC here).
6N2P is a drop in replacement  (same pinout) of: 6N1P, 6N6P, ecc88, E88CC, 6922, 6DJ8. Except the 6N1 and 6N6P have higher heater current. Just add a resistor of say 5 Ohms by 1 Watt to limit current of heaters when substituting either 6N6P or 6N1P.
Read about 6NxP series of tubes HERE