modified in December 2007
My apologies for taking photos with flash - hence the horrible visible dust

Sony CDP-337ESD

The cheapest of the "TDA1541- equipped" Sony range - the Sony CDP710 and its sibling CDP950 on the outside seemed to me identical to my beloved CDP-227ESD but on close inspection I found that the PCB of 227 is muuch better, with better regulation, better caps, better DAC system - better everything. The face-plate is identical BUT in 227 it is metal, in 950 - all plastic. Also mechanisms are different.
So looks can be deceiving.

Similar thing applies to Sony CDP-337ESD versus 227ESD. They look identical. Also the DAC seems the same - a paralleled TDA1541A (non-s)Sometimes the 337 has a non-A variant (better to my ears)
BUT - first - the Sony CDP-337ESD 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 151A is not bad either, but nothing prepared me for the 190A. It is so well made, that Accuphase used it in all their top models. Also Teacs VRDS 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.

All in all - Sony CDP-337ESD is one of the best made CD players I ever saw, in my opinion all things being equal it slightly beats Marantz 80, 94, 95, 94MK2, and also Philips 880 and 960.

Arguably only Sony's own 555ESD and of course grundig 9009 comes better by a hair. I am really impressed.
The Sony 333 ESD is about equal but it has only one TDA1541A chip not two.

What a bullshit about staggered 4D/A.  They simply put two paralell stereo chips, thats all.

Sony CDP-337ESD oversampling

Now if I could only find out how to kill oversampling in this player ! I MUST make it a NOS.

The Sony CDP-337ESD mechanism and laser - Sony KSS190A


Everything in this mechanism - the drawer, the motor, the sub chassis, the clamp - all parts are metal. The operation is not a pleasure - IT IS A DELIGHT !


The clock is 16 Meg type

Unlike all other SONY's, the PCB is white  (??)

Plenty of room in the corner for the new transformer for lampizator. The transformer is about twice as big as in CDP-227esd
The AC stealing point for lampizator transformer is the violet and white wire pins.

Some other Sony CDP-337ESD's have a non-A chips, but mine does have A.

The decoupling caps (burgundy coloured 14 caps per one DAC ) are 100nF. I would prefer 470nF but at least these are premium quality, not SMD crap.

No comments. These caps are to be found in Ongaku power supply.

Unlike for example in AKAI CD55 cheap plastic impersonation, this whole drawer is METAL and the metal decor face is attached by REAL screws.

Impressive spindle, all  machined from one block of metal.

The 190A laser on magnetically floating HAAL motor sledges...

Usual outputs...


I basically repeat the most successful schematics of the Grundig 9009:
Tubes - a pair of 6N2P,
Circuit - 200 Ohm resistors in both cathodes of SRPP lampizator,
Conversion (for parallel DAC) is by 56 Ohm,
Anode power 175 VDC
Current is 1mA.

UIn the second unit I used one Siemens ECC801S triode (a better equivalent of ECC81)
I used it in triode mode anode follower. One half of tube per channel.
The heaters are AC and there is no hum !!!
The Ra is 20K
The Rk is 150 Ohms
R i/u (conversion and grid) is 50 Ohms because this is paralelled DAC. Normally it would be just under 100 Ohms.
Ia is 3,5 mA
U is 150 V
U Out is 80 V

Lampizator - sound

I am not sure which version I like better, perhaps the latter one. In any event - both are absolutely stunning. The dynamics is a little bit better than in the Marantz/Philips application of the TDA1541A. It seems that Sony did a great job understanding what makes the TDA tick.

sony CDP337ESD

There is more voltage regulators than in any other player that I have seen, except maybe the NAIM. But at NAIM the regulators are RELIGION. And rightly so.

sony CDP337ESD

In the red circles you see the signal stealing points. Just lift the shorting pins - the ones marked with arrows in red circles and solder a wire to the empty holes. This forms a perfect signal stealing point. Paralelled with the other DAC but untouched by any other connection. The whole current will flow to the tube grid - resistor 50 Ohms. No capacitor.
In the yellow circle is a pin which is very handy because it represents the ground of the player.

sony CDP337ESD

The yellow and blue wires steal the signal for lampization.

sony CDP337ESD

The Siemens tube fits nicely there, and pay attention please - it is not directly above the DAC because of heat. TDA 1541A is a very hot chip and it needs space to breathe.
The SAA7220p/B is even hotter, it is DAMN HOT chip. At least in the Sony they don't use it.

Final words about the Sony CDP-337ESD:

Is the TDA1541A chip worth every sin ? Yes, especially inside Sony and Naim players.
Is the Sony CDP-337ESD better than the Sony CDP-227ESD weighting half and costing half but electrically almost identical - YES, the KSS190A mechanism is worth its weight in gold.
Is two TDA's better than one ? No, its not.
If you get this player and want to keep it forever - replace the DAC capacitors touching legs 28, 26 and 15 with black gate caps, change the 28 decoupling caps with 0,47uF (470nF) MKP and change the DAC for TDA1541A-S1 crown ones.
That will be the last CD player you will ever own !!!