Pioneer PDS904 versus Radford CD player

Breathing NEW LIFE into CD players

Jonathan Wong

If you are familiar with computers, you will find that no matter how advanced and how powerful the computer is now, it soon will be outdated within three months, or even weeks.

I assembled a PC for my much younger brother about 18 months ago. Recently he seriously complained to me because his PC could not even provide the basic services he wanted, such as high speed surfing, graphics manipulation, watching DVD or play the latest games. His computer was built with an A-Open motherboard, 64M RAM, AMD KR CPU and a 3Gb hard disk.

Reluctantly, I had to spend about S$900, to upgrade his PC to an Intel Celeron 600 (over clocked to 700) system, with DVD player, 15G hard disk, 3D graphics card and a new V90 modem. I suppose the only thing that stayed was just the 64Mb memory module, the old hard disk, diskette drive and the old CD ROM, not forgetting the yellowish casing. However, for S$900, that is a lot more functions added! In the old days people might be proud of keeping things for decades. But with rapid changing of technology, things like PCs seldom last more than a year for many people! Hi Fi is now getting closer to Computers, because of Digital Audio. So, Hi Fi is not spared from this rapid change?? Will the S$1000 CD player become obsolete soon as a PC?

This incident prompted me to conclude from past experiences, develop solutions and publish on UPGRADING CD players in 1388.com !

CD player formats are fixed with the Sony Philips standards, and have been introduced more than 10 years ago. Today, the software available for CD is tremendous and the library is very extensive. CD is a format widely acceptable by many audiophiles. Unless you are looking for the best, and can only live with LP, most opted for CD player because of its conveniences.With the DVD players, CD can live. CD/DVD players are severely crippled by two weak areas:

* Analogue Output Circuit

* Digital Clock/timing Circuit

To illustrate how to breathe life in CD players, two players have been selected: the Pioneer PDS904 and the Radford (small British audiophile company, but Radford also reminds me of Martin Radford, my good friend in Leicester. Where are you now, Matt?). Both are old players but have proven reputation and performances. These are considered mid priced CD players now, and are unable to compete with new players like Wadia or Ensemble. However, after the upgrade, they may even out perform many models with big names. Another reason of using the two CD machines is to avoid offending the local agents: I might expose the flaws of certain current models. Both the Radford and Pioneer can now only be found in the 2nd hand market.

In 1992, I modified Joe Lee’s Philips CD850 using three op-amps from Analog Device and changed the analog and tracking circuits. The player allowed Joe to build a system that stunned many even up to today. Although the op-amps cost less than S$60 that time, the cost of modification could easily exceed $150 to $200 by people offering mod services. Joe’s Philips CD850 went out of service after 5 years of very heavy use. It is now a classic and even many recent players are based on the backbone of the Philips CD850.

The Radford is actually the Philips CD850 backbone with an upgraded TDA1514AS1 Crown Digital to Analog converter, and a very well designed, super audiophile grade power supply and analog board. The board boasts LT1028 IC, which is very expensive and low noise, high performance op-amps from Linear Technology. Despite the age of the Radford, not many modern CD players are comparable to its performances.

The Pioneer PDS904 has an excellent stable platter CD transport. It is also built with high-grade components such as ‘Silmic’ capacitors in the analog section. The Legato Link DAC is well designed, very coherent sounding without any lack of warmth. However, the definition is not razor sharp and the separation is still poor at times.

The two players are compared using the following intentions:

Using a Radford that represents a player that has as much modification done to the Analog System as possible. 

Using a Pioneer that represents a player that has as much modification done to the Digital System as possible.