Will my Dvd give me good playback of CDs or is a seperate CD player Important? (1 Viewer)

[Saurav]

That's obvious I meant the magnitude of the swing, sorry for not making that clearer.

 

[chung]

Suarav:

No problem.

 

[Larry B]

Chung, Saurav, and all the other EE's.
I'm curious as to your opinions as to why some CD players (that includes DACS, so I'm not obsessing about jitter ), as well as pre-amps, sound so much better than others? Some very-well respected designers (Charlie Hansen of Ayre, for example) seems to feel that the DC power is critical, as is isolation of circuits (thus the use of external power supplies). What do you folks think?
Larry

 

[Saurav]

This is where I put on my software engineer hat and let Chung handle this question
I don't think you can ever single out one factor and say "This is what you need to make a system sound good". DC power, for instance - for certain kinds of tube circuits, and very high gain circuits like phono stages, it would make more of a difference. However, you can always have DC power and mess up a zillion other factors and end up with a poor sounding product. As in most things, IMO, balance is the key.

 

[Larry B]

Saurav:

Agreed. And achieving that balance almost certainly entials lots and lots of factors, which is why companies like Levinson, Ayre and Naim (to name three) spend so much time and money on R&D.

BTW, I don't know if this is well known, but I've been told by reliable soures that the high-end companies spend devote considerable energy into optimizing the POSITION of various circuits, as this influences the sound.

Larry

 

[Saurav]

I've experienced that first hand - move the wrong wire by half an inch in a tube circuit, and the noise will go up several times.

 

[chung]

Larry B:

I'm curious as to your opinions as to why some CD players (that includes DACS, so I'm not obsessing about jitter ), as well as pre-amps, sound so much better than others? Some very-well respected designers (Charlie Hansen of Ayre, for example) seems to feel that the DC power is critical, as is isolation of circuits (thus the use of external power supplies). What do you folks think?

Well, I think the key is "sound so much better". I have listened to a lot of CD players, and there are ones that sound noticeably worse, but the majority of them sound very similar to me. With analog preamps, my experience is that if you use the line-level inputs, all competent preamps sound very similar, assuming you are not using any tone-controls. The difference is less than what you get from different power amps. You may want to read Roger Russell's website (he's from McIntosh Labs, and I provided a link earlier in this thread) where he described his measurements with amplfiers. Preamps are easier to design than power amps, and there are fewer things that can go wrong. That's not to say someone cannot screw things up, though.

If you are talking about phono-stages, then very noticeable differences exist among different preamps. The phono cartridge loading that the preamp inputs present, and the design of the RIAA equalization can have major effects on the sound. That's one of the reasons why I honestly believe the CD technology is a much better one. It is also not easy to say which one phono stage sounds better. When people say things like "open, airy, veiled, bright, dark, warm, etc." I don't know what they mean, and I have a suspicion they don't either. Most of these can be described more precisely with frequency response and distortion measurements. It is difficult to find a RIAA design that is accurate, for instance, to 0.3 dB across the whole band, and I have seen deviations > 1dB all over the band. Those deviations can account for the differences that are audible easily.

When you are comparing tube with solid state, then the differences are very noticeable and understood. I, like most audio and electrical engineers, do not consider tube amps accurate. I understand why people like them, and that's OK. I have owned tube amps, and I never regret selling them.

Back to CD players. Here's what I think, in order of importance, are the things affecting the sound:

1. DAC's.

2. Analog design (filters, output stages, power supply, etc.).

3. Digital design (jitter, error rate, etc.).

DAC's are a lot better today than in 1982, so there is a detectable difference. However, some of the DAC's even back then are pretty good, and some early '80's CD players still sound good compared to present day players. There are certainly bad players back then, too. Today's sigma-delta DAC's are linear almost by virtue of the architecture, and it is no problem getting better than 16 bits of linearity. The oversampling architecture has just about eliminated the problem of the reconstruction filter causing in-band aberations. The expensive players tend to pay more attention to power supply decoupling, digital noise decoupling, better crystal oscillator design, better mechanical design, and so on to gain a marginal sonic improvement, but the servo and the read mechanisms are very similar between an expensive and a sub-$200 player. I do not believe you need separate transports and DAC's to get execllent results. I think that Meridian Labs probably make some very good CD players, based on what I have read on their website and what other audio engineers have written about them. I have not listened to them though. If I were to buy one, and I have a $1K budget, I would seriously consider them. I have read some of the papers that Bob Stuart, the chief engineer at Meridian, wrote, and he understands digital audio well, in my opinion. I can't say the same thing for all other "hi-end" designers.

Placement of circuits make a difference in noise pick-up, but those things are not hard to understand and do correctly. They also show up in measurements, so there is really nothing "black-magic" about placements. When you said that high-end companies put a lot of money on R&D, you have to understand the relative scales. A good EE will cost anywhere between $200K - $300K per year. So even one EE could be a large burden for a small company. Companies like Sony probably have >1,000 engineers developing audio products. Today's pre-pro/receivers are quite difficult to design, because of the mix of digital and analog circuits. Traditionally the high-end companies employ analog designers, so they probably have a hard time now finding people who can do the digital design/firmware well. Like I said earlier, very few young EE's go into audio engineering, so I see a major problem for the boutique companies to compete well with the large manufacturers.

When you said there are big differences, was that based on blind testing?

 

[Saurav]

The phono cartridge loading that the preamp inputs present, and the design of the RIAA equalization can have major effects on the sound.

Noise becomes a bigger factor too, because of the high gain involved. A 0.1mV difference in noise level between two opamps means practically nothing if the opamps are used in a line stage application, but will make a bigger difference if that same opamp is now used in a phono stage.
That was a good post.

 

[chung]

Larry B:

BTW, I don't know if this is well known, but I've been told by reliable soures that the high-end companies spend devote considerable energy into optimizing the POSITION of various circuits, as this influences the sound.

Have you tried out the new portable MD players? They sound surprisingly good. The size is just a tad bigger than a stack of business cards. That's an amazing feat of engineering, putting so much electronics, with moving parts, into so small a space. Compared to that, positioning and packaging circuits in a high-end pre-pro (where space is infinite by comparison) is a walk in the park.

As an engineer, I have tremendous respect for those at Sony, etc. who pull these things off with incredible regularity.

 

[Larry B]

Chung:

Thank you very much your response.

When you said there are big differences, was that based on blind testing?

No it was not. I should perhaps mention that I am a scientist by training, and have published numerous articles in some of the best journals in my field (neuropharmacology), and hold nearly a dozen patents. I mention this not to brag, but to indicate that I am a firm believer in the scientific method. However, I feel that there are many problems associated with blind testing when it comes to audio testing. (By the way, I also do not use blind testing when I choose a favorite food, nor a favorite piece of music, nor a favorite masseuse for my old and aching muscles.) This does not mean that I feel that blind testing of audio equipment is all bad; rather, that the good is outweighed by the bad.

I am well aware that I, like most everyone else, is biased by certain preconceived notions. On the other hand, twice in the past 6 months I have compared 2 pieces of equipment (different pieces each time) and both times, I ended up preferring the piece that was not the one I went in "wanting to like." Interestingly, in each case I intitially liked the one I thought I was going to like but after extended listening, I changed my mind. It was not easy shelling out hard-earned cash for a decision that flew in the face of my established beliefs, but after many hours of listening, it became clear which product brought me more satisfaction.

I guess that's a long answer to a short question.

Larry

 

[chung]

Suarav:

The $200K to $300K includes overhead, which means the salary is anywhere from $120K to $200K. If a company hires a consultant, then the $200K to $300K is the actual compensation to the consultant, amortized to per year.

You're correct that the noise in phono-stages is important because of the high gains. Typically, though, the noise from the LP and cartridge dominate, in any competent preamp design.

 

[Saurav]

Typically, though, the noise from the LP and cartridge dominate, in any competent preamp design.

True.

 

[Larry B]

Chung:

Have you tried out the new portable MD players?

I have not.

Larry

 

[chung]

Larry:

However, I feel that there are many problems associated with blind testing when it comes to audio testing. (By the way, I also do not use blind testing when I choose a favorite food, nor a favorite piece of music, nor a favorite masseuse for my old and aching muscles.)

The difference, at least as far as I am concerned, is that there is a well-defined goal in audio equipment: accuracy. Choosing food, or music, or who is your favorite masseuse are fundamentally different issues, because personal opinion is what matters.
Now if you believe that personal opinion is the most important thing in choosing HiFi, that is a position I can respect. But it will be very difficult for you to convince others that a piece of equipment is better, or simply different, than another, without some sort of scientific testing that removes the personal biases.
I should probably stop here before I get myself any deeper into DBT debates .
There are also other factors in buying decisions: aesthetics, reliability, ergonomics, prestige, etc. Those are perfectly valid factors.

 

[Saurav]

Now if you believe that personal opinion is the most important thing in choosing HiFi, that is a position I can respect. But it will be very difficult for you to convince others that a piece of equipment is better, or simply different, than another, without some sort of scientific testing that removes the personal biases.

I really don't see why anyone needs to go beyond "I like this more". Trying to find further justification for a decision is probably more about ego (and/or insecurity) than anything else

 

[Larry B]

Chung:

As has frequently been mentioned here and elsewhere, few of us actually know what the original event sounded like - - - we can only guess. I choose equipment based on (1) its (their) ability to sound most like what I believe musical instruments (including voice) actually sounds like, and (2) the pleasure I derive from it.

As for DBT, I suppose it's possible that every audio review ever conducted has been based on imagined differences, and it is unlikely that I can prove otherwise. However, it is noteworthy that, at least in the case of The Absolute Sound, the reviewers usually agree on the sonic properties of equipment, irrespective of their own personal preferences. That is, they seem able to separate the objective from the subjective, not unlike wine tasters.

Larry

Edit: Saurav, you have one again hit the nail on the head.

 

[Pete Gia]

I have an older Sony 7000 DVD player. This piece has separate pickups for DVD or CD. It does a GREAT job for CD..However,I have a separate CD player. My reasoning is that there`s less wear and tear on the DVD player. Good Luck----Pete

 

[chung]

Larry and Suarav:

I don't disagree with the fact that measurements don't tell everything about actual performance; that was not the intention of the post where I brought up accuracy. My point is that blind testing should reveal those differences even if they were not measurable on the bench. The fact that measurements do not relate well to performance is a tangential issue. Once differences have been established to exist, via blind tests, that we should investigate what cause those differences, and if the current measurements are insufficient, devise new measurements.

The problem today is that there is no consensus that some claimed differences exist (as in the case of cables), and DBT does not validate the claims that such differences exist.

I promise this is my last post on this thread on DBT. If someone wants to read more, do a google search on the rec.audio.high-end newsgroup. There is a debate ongoing right now.

 

[Saurav]

I wasn't referring to differences in cables, or anything that ususally gets discussed in the DBT debates. I'm talking more about, say, differences in 2 pairs of speakers, or 2 amplifiers when used with the same set of speakers, even though the superficial measurements show that they should perform very close to each other.

 

[chung]

Suarav:
I do not disagree with what you said.
It is very difficult to come up with a set of specs that will tell us how speakers sound in our rooms. Power amps and preamps are easier. The typical specs in a data sheet are not always sufficient to characterize power amps because of the reliance on resistive loads. To make matters worse, some amps do not meet published specs. Having said that, all power amp designers would start out with a set of specs they want to achieve, and then supplement that with live testing on a range of speakers.