Upconverting DVD players..how does it work? (1 Viewer)

[AmusingistheDawn]

Joe,

I totally agree with you...however, where do you draw the line? What made you decide to buy what you bought? Obviously the AVR does make a difference, as it does a multitude of things. I have a $1200 AVR. What price for an all in one is justified to match my AVR?

At this point i'm ready to dump the oppo and find an "all in one". You raise some good points, I just wish some people like RAF would chime in. What justifies the purchase? I notice that items like the sony 550 and panasonic 35 are popular for the average consumer that can't afford $2K BD players, but what you are saying is that the quality is the same?? Do you understand my point and why this is so confusing?

I would just like to hear from some other people that can help clarify something: Why do people buy seperates? Or is it only the big spenders that do so? With a budget of $600, will I ever be able to hear a difference in stereo playback through an "all in one"..compared to a stand alone CD player of the same price?

 

[Greg_R]

I'll throw in my 2 cents. Note that my thoughts lean more toward the scientific side then the audiophile side of the argument / discussion. When I say 'high end' I'm talking about a $1k+ kind of player.

Let's take a CD player as an example because it's less complex than a DVD or Bluray device. A CD player contains the following major parts: Enclosure, transport, power supply, DAC, Clock circuitry, and Analog ouput stage.

Enclosure The enclosure is the 'box' surrounding all of the parts. Higher end players tend to have a much beefier and heavier enclosure. They also tend to be more aesthetically pleasing (pretty lights, knobs, switches, etc.). Everything tends to be over-engineered and has a very 'solid' feel. Some enclosures include additional EM shielding (copper Faraday cage, etc.) to prevent external electronic noise from affecting the internal circuitry. A good enclosure also dampens external vibration which can affect the transport circuitry. My current CD player is an old Pioneer Elite DV-05 that does not have the best enclosure design. During loud sound passages, my stereo can actually make discs skip when I use this player. A high end enclosure would not have this issue (hopefully!). I fixed my problem by sticking a marble slab on the top and air-packing material on the bottom ($5 fix). However, my experiences do highlight the benefit of a quality enclosure in certain situations.

Transport The transport encompasses the mechanical mechanisms and electronics that read the bit stream from the disc. Sony, Philips, and Teac all make transports with the Sony being the most popular (cheapest). All three do a good job but the Teac's mechanism is very beefy. An argument can be made that the error correcting code found on each CD eliminates the need for a heavy-duty transport. Most high end manufacturers start with a basic mechanism from these manufacturers and tweak it so they can claim some form of added value.

power supply The power supply converts the inbound AC power and sends ultra-clean DC power to control the various functions of the player. A good ground system (star, etc.) will help create a very low noise floor. High end or modified CD players often upgrade the power supply for the analog section of the player and have a separate supply for the transport and drive motor. This keeps the electrical noise from the motor and clocking circuits away from the DAC and analog output logic.

DAC DACs convert digital information to an analog waveform. A more accurate term would be "reconstruct" the information. It can be mathematically proven that an _ideal_ DAC can perfectly reconstruct a bandwidth limited signal (CDs = 0->20kHz). Read up on the Nyquist and Fourier theorems for more info r.e. the math of reconstruction. A lot of forum arguments hinge around whether an ideal DAC is possible and whether we are losing important audio information above 20kHz (analog vs digital debate). The best DACs today measure very well assuming they receive clean power and an uninterrupted bitstream. High end manufacturers go a few steps further by adding dedicated power supplies, upsampling, deeper buffers, DACs in parallel, and other redundant features to make the DAC operate in the most ideal fashion possible.

Clock circuitry All CD players are controlled by an internal master clock. The clock ensures that the transport and DAC are working synchronously with each other. The accuracy of this clock is a big selling point by high end manufacturers. Often a lot of parts are dedicated to creating an ultra accurate clock (where 1-2 parts are used on a cheap CD player). If your DAC has a deep enough buffer, "misses" due to poor clocking can be tolerated (this is standard on all but the cheapest devices). Also, clocking circuitry on a high end device is often powered by a different supply then the DAC. The noise from the clock circuit tends to pollute the DAC's power (which affects it's accuracy). Ultra high-end devices use an external master clock (Apogee Big Ben, etc.) so there is NO clock circuit inside the box.

Analog ouput stage This is where the player takes the low level analog signal from the DAC and amplifies it to a line level output. You could view it as a baby amplifier in your CD player. The quality of these amplifiers differ significantly. High end players focus heavily on these circuits while cheap players tend to use an off the shelf solution. The differences between a cheap player and a quality solution's analog stage are measurable and audible on most systems.


So, if you are only using the digital output of your player, do you need a high end transport? As long as the transport can handle in-room vibrations and your external DAC (likely in your receiver) has a deep enough buffer to recover from errors then my answer would be no. Personally, I have ditched the mechanical transport entirely and have been using a ripped lossless copy of my CDs for critical listening. Many high-end audiophiles have also experimented with this approach (using battery powered DACs to eliminate the power supply issue + high end HTPCs to read the files). Also, PCM is being ditched in favor of USB and I2S for these systems (packet vs streaming data, clocking is no longer a factor for transmitting the data).

 

[AmusingistheDawn]

Great information. Thanks!
I think I'm going to just buy the panasonic 35 BD player and use it for everything. I said this in another forum...1 avr, 1 player, 1 tv, and 3 hdmi cables...very very simple. By only spending $200 on a player, I can invest the rest in a fund for new speakers.

 

[seedybrick]

personally i have separate cd/dvd/bd players because i feel that an all in one would simply get too much abuse in my house.

at least with 3 components i'm spreading out the wear and tear


anyhoo.....why are you using analog outputs for your CD player?
the only reason i can think of is for SACD??