I have the CD4000 last ten years. It gives me satisfaction.
This is a drive to its well-balanced, fair, not aggressive. A beautiful sound, simply. The sound spectrum is well distributed, naturally. The stamps are real and beautiful. The definition is excellent. Everything is comparable to what I got a good player mission that I had before, and which it is a misfortune happened ...
For the price, this was unexpected. Basically, this is clearly a Philips player. There must be a way to improve greatly as indicated Blérald Christian, replacing the operational amplifier and changing the diet completely. But it is beyond my skills and I did not venture!
However, I got a significant improvement without opening the unit. It now rests on a granite slab 2.5 cm thick. Device based on another granite slab, 4 cm thick (see photo). (This is Christian Blérald who recommended me to place the thicker of the two plates above and not below.) The result is impressive, not easy to describe in words: sounds seem much cleaner (attacks harpsichord notes, for example), but it gives an impression of "calm", lack of stress in restitution.
The CD4000 is my third reader; I first had a Philips (very good) and a Mission.
I feel no need to change the drive and hopefully keep the CD4000 long time.