how the process all those digits and then how they amplify the signal. I'm sure someone will have a much more in depth comment, but it'll likely be the same when boiled down.
Ever see a digital camera image when blown up? start seeing those pixels? The smaller the pixels the better the resolution. Ditto for CD players. When you blow it up, it's synonomous to amplfying the music, little errors all of sudden become big.
Hope that helps in laymans terms |
The digital to analogue converter (s) selected play a big role, the more accurate and less prone to inaccuracies the better; Crystal Semiconductor and Texas Instruments (bought Burr Brown a while back) make some of the better known and respected DACs.
The quality of the transport makes a difference as well. The transport motor needs to be accurate (think of variations in speed on a turntable, same thing), stable so there aren't unnecessary and unwanted vibrations, and of course a good quality laser mechanism.
Like all electronic equipment the power supplies make a big difference, filtering out the grunge and providing a pure, clean voltage reference to the inards of the player. Some of the better CDP's have seperate power supplies for the digital and analogue sections of the player.
Finally, keeping airborne nasties out by extensive shielding teechniques is the hallmark of a good design. Goes without saying the quality of the various external parts impact the sound as well; the RCA and/or balanced jacks, power cord, etc....
Once you take all these things into account it's easy to see how CDP's vary in sound from one design to the next. Equally important to note turntable designers face some of the same challenges (obviously no DACs to deal with though). If you can, buy a top notch vinyl rig as a reference to compare how well various CD players sound in your setup. |
What separates the best from the rest is the quality of the analog and output sections. This is where the sound happens. Upgrading and modifying the analog and output sections of a CD player is mainly what Stan Warren, Dan Wright, Dusty Vawter, and others do when performing their magic.
The DAC chip while still important, is secondary. There are many high quality older 16, 18 and 20 bit players that will still sound a lot better than a cheap 24bit/192 DVD/CD player.
Jeff can probably tell you about the quality of the old 20 bit Burr Brown PCM-63K grade mono DAC chips. |
Specs & measurements. I don't have a clue what i'm talking about but i hear this is very important. I heard about this from a guy who thinks he is a reviewer. Or i guess is one.
JA from audiophile. Wouldn't dare try listening to one unless it measured up to the required measurements. |
A lot has to do with the DAC's used but also how they are implemented. Power supply isolation and capacity plays a big part. I personally think the jitter level is a very important factor. It seems to follow the other items listed and ultimately effects the sound you hear. There are a lot of reasons for difference. As this thread progresses, you should get the idea. |
Tom,
You're right, the PCM-63K's were some of the best DAC's I've played with. Damned expensive, I think they were around $60 a pop (the K version denotes military grade and were much tighter tolerances). Smooth, analog sounding and definately worth the price of admission. Sadly they were discontinued in favour of the PCM170x series. Crystal is making some fine stuff these days, showing up in most of the better units on the market. Advances for sure but still not the equal of my turntable... |
Some high end CD players like the tube based BAT VK-D5SE uses four PCM-63K (two per channel). So based on Jeff's quote, BAT spent $240 just for the DAC chips. |
Which one use my ML 36s ? Hope it is OK to ask her!
Thanks |
Krazeeyk: You've asked a very difficult question, actually. Despite a plethora of "theories," attempts to corrolate sonic differences to technical attributes are pretty much purely speculative. |
Saw this thread last night, before anybody had posted on it. I was thinking about all the kinds of responses it was likely to draw, and wrote out a fairly long, fairly philosophical response in anticipation of the onslaught, which in the end I thought better of and decided not to post after all.
Looking at the above, it's partly what I had expected, with the exception that no one seems to have taken the tack of telling the questioner what to listen for. Either way, I don't think this approach is necessarily going to help him buy his CDP - not that I know for sure what will.
Krazeeyk, from your other posts it looks as though you're just getting started, and trying to assemble a system on a $5K budget. It appears you may have already gotten some Sonus Faber speakers and Musical Fidelity amplification. I can appreciate the intent of your question, but it's really so broad that it can't be satisfactorily answered. In other words, no one can draw you up a laundry list of things to look for in a CDP which will help to choose one to buy used online without prior auditioning. It just doesn't work that way. Although there's no substitute for actual listening experience, if you must choose sound-unheard, why not post a short list of your leading contenders, so respondents can make specific comments about your possible choices? |
Hello all,
Thank you all for your responses, I will look into them in more detail. Zaikesman, this question came up after I pretty much decided on a CD player. I was just curious to see what paper specifications made a difference. I am familiar with D to A conversion, but not familiar enough to know how implementation specifics affect the final product. From what I understand, the beauty about digital is simplicity, its why we use it in the first place. It makes processing that much easier. But how that affected the sound of a product when compared to one costing 3 times as much is really a mystery to me. Its not as obvious as comparing cds to records. The question also stems from some discussions that I've read about Naim and Meridian units. From what I've heard, they are all fine and dandy, but I never really got the chance to take one home to really do some great comparison. I wanted to know if there was really a paper basis to justify the significant price. Being on a budget, I elected to take the second hand route, therefore did not want to pester hifi audio stores. Since I have no real intention of buying from them. So I am basically left with trial and error as my only means of finding that system I like. I am one that honestly believes that the way it sounds is all that really matters, the room I will be using is also quite large, larger than most listening rooms I've been in. Before I found out about audiogon, I did listen to the Grand Pianos, and serveral B&W nautilus speakers. I just liked the Fabers that much better, though that is the last component I am planning on purchasing. I do not really expect to gain that much exposure to other speakers, so I am pretty much limited to the choices that my experiences dictates. The musical fidelity gear is also a gamble, I've just read that they work well with the Fabers and are in my budget, thus I am on the market for those. But if you have any alternative amplification components, I'll gladly look into them. There are just too many variables in the equation for me to be able to merely isolate a single component to a certain sound, especially since I haven't heard these components together. So the only real way for me to get a good feel for whats going on is to take a small gamble. I have pretty much made a deal for an Arcam cd72 player. Buying it second hand lets me avoid the huge depreciation hit in the event I find it just isn't working out. I was considering the Musical Hall mmf-25 and the Rega planet 2000. Which I may try out later in this lifetime, but the deal arcam seemed pretty good, so I took the risk. I have an old magnavox that I've been using (one of the first cd players to come out)which I will make my own comparisons on. Hopefully I will find that the arcam is much better, or I will have to re-evaluate this whole hifi thing. Zaikesman, I hope this kind of narrows the playing field of my question. You do make a valid point about "what to listen for", and I would appreciate some insight on that if you would be so kind. This can help me during my evaluation of the Arcam. I have an idea of what I would like to hear, but do not know yet which component is responsible for it. One thing I really enjoy and look for is the full extension of an instrument. The plucking of a guitar string, the complexity of a symbol strike and its fully extended decay, the reverberation of a bass drum, and the extension of the rattles on a snair. These are things that I have started looking for in the music I listen to, but I lack the experience to tell me what component does what. If it is a cd player that does this, I could use some suggestions as well.
Thanks in advance |
Krazeeyk, you are pretty much correct about the process you're about to be going through. But don't feel badly - trial and error is a continual experience for audiophiles with a lot more years and gear under their belts than you. I'm not going to try to tell you what to listen for; that wasn't my intent in bringing that up - rather merely to say that even if respondents made a laundry list of sonic attributes, that wouldn't be any more helpful than a list of design features, or paper specs as you put it. You've just got to start somewhere, and keep listening. Besides, you really can't start right from the beginning with your ultimate system, or even one for a price, without experiencing some different stuff in between through an upgrading process, especially if you're not auditioning beforehand. And I admire you for not wanting to waste the time of dealers if you have no intention of buying from them. You're correct about using Audiogon to minimize your financial risk in trying stuff out in your home.
Anyway, to get back to your questions, I don't know about digital being simplicity (that more describes analog), but I can say that specs and chips and design features aren't necessarily going to tell you much about what a player will sound like. I can also tell you that digital differences can be pretty subtle, compared to speakers or amplifiers (though they don't have to be), and that you probably can't go way far wrong in choosing from among the various moderately-priced options in your range - none will sound like the best, but none should ruin your sound either My best advice would be to try and stick with well-known makers and pretty up-to-date models, just as a hedge if you decide to sell again. I'm sorry I can't comment on the specific model you're talking about getting, but maybe others can. Best of luck and happy listening! |
Krazeeyk,
I will try and shedd some light on a few topics..
Physical layout:
The PC board layout has a huge impact. Think of the board layout for a CD player as a 3 bedroom house floorplan one room for the digital components one for the analog one for the power supply ect... The reason the PCB is split into 3 rooms (or atleast should be)is to isolate noise from the Analog section.. (think analog clean and pwr supply/digital dirty). Usually what will happen is the D to A converters will bridge the analog and digital sections of the PCB because the converters need an analog pwr/gnd and digital pwr/gnd and we want to keep those pwr/gnd's seperated as much as possible but eventually they will need to tie together. Typically for a "quality design" the PCB will have atleast 4 layers. There are exceptions but not many.
That is a very general explanation... The difference bettween a good PCB layout and a bad one is how someone
goes about doing what i explaned. Most chip manufactures will give some physical guidlines for implementing their chips... (that someone has spent alot of time on figuring out) and a good engineer will take that info into consideration. A good engineer will have the ability to translate whats on the spec sheets and his schematic into a Physical layout that takes into consideration whats going to take place on the PCB.
Component selection:
Simple... without quality components you dont get hi-fi.
The better the components and implementation the better
the results. I think someone else mentioned the output
stage and the guys doing tweaks.. What they are doing is
"upgrading" the components. But if its a bad PCB layout
(poor grounding, poor component placement, poor trace routing.. ect.) the product still wont be what it should.
Jitter:
Jitter is a timing problem between digital domains. Think of it as you trying to syncronize your wrist watch to the
clock on the wall that keeps changing (i cant think of another analogy right now). Jitter can be caused by many things including Crappy cables, Pwr supply noise ect... With many outboard DAC's what they will do is take the signal and re-clock it and get the jitter out as well as upsampling ect.. A good CD player will have been designed for minimal jitter in the first place. Jitter is a killer
in any digital domain but where it really hurts is in our
beloved hi-fi equipment because we hear it...
Those are a few areas that will differentiate a good CD
from a bad one...
Hope that helps. |
Took a peek to see what direction this thread headed towards, and the "trust your ears" is always sound advice (pun intended). I posted some pseudo-technical stuff as a response because ALL good sounding CDP's take these things into account. I'm a geek and a tweak, love to pop the hood and see what's what in gear. Partly due to my job, I've been in the semiconductor business for 20 years. Bottom line, if the designer ignores these fundamental issues your ears will bleed.
I was one of the unfortunate souls that bought a CD player when there were two titles available, and have upgraded many many times over the years. The advance in digital has been obvious but sadly still comes nowhere near vinyl for musical enjoyment. |
