What is purpose of a cd transport?

Go listen and judge for yourself.......

To supplant Rcprince with an example -- some cdr/dvd-r are better than others. Some power supplies are more elaborate than others. Why separate? Good question -- sometimes it;s just a matter of space, sometimes marketing.

Pbb's post wasn't here when I posted. In theory, a well-designed one box player should beat separates, because that's one less interface and a shorter path for the electronic signal. In fact, the original CD players, with the main exception of Sony's state of the art two-box system they came out with (the 703?), were one-box units. Separate DACs came into play from the high-end designers to take advantage of the additional space in the separate box for the better power supplies and analog sections that couldn't fit in (or for pricing reasons weren't put into) the standard CD player's chassis and because the original one-box players didn't sound that great; then companies like TEAC began manufacturing no holds barred transports that were built like tanks and were far better than the cheap mass-market CD player transports. At that point, with no real high end manufacturers involved in the single box CD player business, a separate DAC made more sense to a person who wanted a better-sounding CD playback system. Now, the power supplies, analog sections and transports in the better one-box players are on a par with the better separates and may have tipped the scales the other way, though a well-designed inexpensive DAC (and there are plenty of them) is still a viable alternative for better sound from an inexpensive CD player. I personally have heard differences in some, not all, transports, but I don't really feel they come close to the magnitude of the differences I've heard in DACs.

There are two completely separate parts of digital playback; the reading of the source material and the conversion of that digital data into analog sound. To perfect them both is two separate tasks. Having them together in one box only makes perfection harder to achieve.

If you an expert digital design engineer, what do you know about making a transport? There are a lot of companies that only make the DAC. If you limit yourself to one box players, you are missing a huge part of the market. You are also missing most of the higher end of the market.

Look at turntables. What if the cartridge and phono stage was built perminently onto the turntable? If you wanted to change something you would have to buy a whole new turntable. I don't know any audio person who would consider that an improvement.

That is actually one thing that turns me off to the lower end of the audiophile turntable market. They are all selling plug and play solutions. You have to pay for the cartridge they picked for the turntable. Back in the pre-digital days in the 70s and 80's the cartridge was mostly a separate purchase, even if you were just buying the entry Dual turntable.

Blue Circle just came out with a two box version of their DAC. The very large power supply is in a separate box. So with the transport you have three boxes in total. MSB has had separate power supplies for years (the P1000).

Audio Logic has done the same thing with their DAC in the past (the new MDX version is a one-box DAC)--in fact, their prototype actually had three boxes, one for the DAC circuitry, one for the analog power supply and one for the digital power supply. With my Forsell's air pump, I have four boxes instead of one. My non-audiophile friends roll their eyes a lot. Does it all make a difference? I think so, but in objective terms the difference all of my esoterica makes is probably very little in the grand scheme of playing music, otherwise I could not be moved listening to music on my car radio.