june/ july 2008
The heaviest of
the "TDA1541" range Sony CDP-555ESD on the outside
seemed to me identical to my beloved CDP-337ESD
close inspection I found that the PCB of CDP-555ESD is slightly
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
The face-plate is (almost) identical BUT on close inspection it is
totally different. Differences are a millimetre here and there, but
is a DIFFERENT thing. So looks can be deceiving. Funny why they did not
use parts sharing in the production.
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.
227's mechanism KSS151A is not bad either, but nothing prepared me for
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
plate. The mighty KSS190A is also similar to Kenwood's
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
All in all - CDP-555ESD is the best Sony so
far, one of the best TDA1541 players so
and overall - one of the best players so farperiod. Sonically it looses
Wolfson DAC but only by a hair.
Sony's own 557ESD may even be better by another hair. I
am really impressed.
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
I thew the towel. Sorry.
KSS190A Mechanism ald laser
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
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 !!!
not A and not S1
DAC is hidden underneath a ceramic red plate.
I dunno what for - vibration? Heat dissipation? Temp stabilization? All
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
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 WWW.alldatasheet.com
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
tube holes required some serious disassembly job ....
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.
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.
SRPP, both cathode resistors 180-250 Ohms, ideally 200.
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
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