Can I really hear a difference between two cheap CD transports?

[abacus]

Cannot understand why no one ever sticks to the original post. The need to spout knowledge continues I guess.......

I'm still waiting to hear what amp the OP managed to connect a CD transport to. Presumably one with an inbuilt DAC.

the store guy described the difference in sound to me

In other words, you heard what he wanted you to hear, not what you actually heard. (Just one of the many tricks of the trade that dealers use to get you to buy what they want you to buy, rather than what’s best for you)

Bill

 

[keeper of the quays]

Cannot understand why no one ever sticks to the original post. The need to spout knowledge continues I guess.......

I'm still waiting to hear what amp the OP managed to connect a CD transport to. Presumably one with an inbuilt DAC.

 the store guy described the difference in sound to me?

In other words, you heard what he wanted you to hear, not what you actually heard. (Just one of the many tricks of the trade that dealers use to get you to buy what they want you to buy, rather than what’s best for you)

Bill

to be fair to hifi dealers..its important to give a good first impression! Years ago my mother and her husband went to audition some hifi..i went with them..they seemed to think i knew something bout hifi? Lol..(I know nothing! Therefore I know something? Which is nothing!! Lol) I can't remember which speakers they auditioned but the sales assistant wired them up wrong way round? Sounded bit 'meh' even though he explained his mistake..no amount of listening altered the fact that initially they sounded 'meh' so they weren't bought! They ended up with Yamaha cassette player, tuner..a aura amp and a Linn turntable...heres the mad thing..my mothers husband had a old pair of whafdale Linton's knocking about so they used those! Horrid speakers..all that money spent..if that twit sales assistant actually knew what he was doing they would of had a decent pair of speakers!! Nuts really!! Upshot of my tale is aura packed up! Then replaced with a horrid cheap amp courtesy of my sisters husband..tuner died too...but happy ending! (no..not Thai massage parlour! Haha) I now have the Linn and Yamaha cassette player..going through my quad/musical fidelity and AE1mk3s..sounds lovely...my mum never got to hear it sadly..i inherited the hifi...this post is wildly off topic? However the the need to spout knowledge is what it is...no knowledge in my story..just a anecdote...a hifi one! No less...

 

[cheeseboy]

I take your point, but is it bias? Expectation is just that! I expect a £700 cd player to sound better than a £250 cd player,

expectation bias is necessarily about the more expensive being better, it can also be the fact that you've changed something so you expect to hear a difference, regardless of what that difference is.

 

[Rups]

In other words, you heard what he wanted you to hear, not what you actually heard. (Just one of the many tricks of the trade that dealers use to get you to buy what they want you to buy, rather than what’s best for you)

Bill

Understandable comment given how I described the situation but nope, absolutely not. I am probably the most sceptical person in the world and was particularly disinclined to listen to a word this guy had to say as he was a wide-boy yoof who didn't seem to have much knowledge and was keen just to make a sale. I made a mental note of what I thought the differences sounded like and then I told him that I thought they both sounded great (lie) but different and asked him what he thought. He looked startled and scared and then sort of gave in and stammered something out. What he offered was spot on. Without him I then listened to the bit with the electronic beat a couple of times in the Yamaha and could hardly pick it up at all, which seemed less about quality of sound and more a matter of fact. On returning to the CXC it was still there clear as day.

If we're going to get technical here then the only way I can think of that one of these two transports could possibly sound different would be if:

A) one of them was actively modifying the sound at the digital stage; or

B) there was some significant degradation of the digital signal in one or both of them that the DAC was then having to 'paper over'

I suspect there must be a bit of the latter going on.

have decided to go the EBay route suggested by an earlier poster anyway as on reflection there seems to be good stuff out there. (Van loads of pristine Arcam 7SEs for example...though not convinced the Arcam style is for me)

 

[Rups]

expectation bias is necessarily about the more expensive being better, it can also be the fact that you've changed something so you expect to hear a difference, regardless of what that difference is.

I'm still happy to accept (though not convinced in this instance) that this may be partly or entirely the explanation. But it wasn't any psychic suggestion by the shop assistant. I also doubt my playful suggestion he may have sabotaged the Yamaha audition! (After all I watched how he wired it up)

 

[cheeseboy]

I'm still happy to accept (though not convinced in this instance) that this may be partly or entirely the explanation. But it wasn't any psychic suggestion by the shop assistant. I also doubt my playful suggestion he may have sabotaged the Yamaha audition! (After all I watched how he wired it up)

as I said before, I wasn't saying that expectation bias is/was the reason for hearing differences, just that unless you specifically do things to try and rule it out, one can't discount it as a reason for hearing differences.

 

[MajorFubar]

There's really only one way to answer this: digitally record a track from the same CD to a computer from each transport, perfectly align them in a DAW such as Audacity, and see if they null each other when you invert the phase of one. If they do, then the outputs are the same. If they don't then they are different. Most people already have the tools to do this, you just need a soundcard in your computer with an appropriate coax or SPDIF input and Audacity is free to download.

Two types of people will question the validity of that test though. Firstly, you'll get the type of people who say they don't have the technical competence to carry out such a test and why should I expect them to have. Then you get the type who say digitally recording the output from the two transports to a computer is not the same or representative of plugging the transport into a DAC and listening to the output. Truth is, with both types of people, they simply don't want to be presented with indisputable evidence which proves them wrong (assuming the null test proves there is no difference, which it should).

 

[davedotco]

There's really only one way to answer this: digitally record a track from the same CD to a computer from each transport, perfectly align them in a DAW such as Audacity, and see if they null each other when you invert the phase of one. If they do, then the outputs are the same. If they don't then they are different. Most people already have the tools to do this, you just need a soundcard in your computer with an appropriate coax or SPDIF input and Audacity is free to download.

Two types of people will question the validity of that test though. Firstly, you'll get the type of people who say they don't have the technical competence to carry out such a test and why should I expect them to have. Then you get the type who say digitally recording the output from the two transports to a computer is not the same or representative of plugging the transport into a DAC and listening to the output. Truth is, with both types of people, they simply don't want to be presented with indisputable evidence which proves them wrong (assuming the null test proves there is no difference, which it should).

Some time ago I was involved with a company that did something very similar during it's in house investication of transports and mechs.

You may recall that back at the dawn of (digital) time there were a few dacs and players that had led indicators, that flashed when errors were detected in the data stream. Hi-fi buys found them irristible to the point that cds and the players themselves were being returned in large numbers due to the 'number' of errors, such players dissappeared from the market quite quickly.

Well, one company used similar technology to monitor the error correction cuircuit so that it could compare the number of errors in the data stream of various transports. Many devices were tested and repeatable results were obtained that showed a great variation between models and even between samples of the same model.

Results showed that the two stand out mechs to be the Teac VRDS 25 or 25x and at lower cost the Pioneer Stable Platter. The cheaper VRDS 4x and the various Sony and Phillips mechs all produced many more errors. I actually watched these tests being carried out, the differences were not small.

Bear in mind that these were 'measurements', not listening tests so I am not in a position to state whether these differences were or were not audible. Such tests were carried out but I was not party to them.

All I can say is that th companies top players continued to use the expensive VRDS and their choice for their entry level ($2990) player was the Pioneer.

 

[Jota180]

You may receive quite a number of replies from certain members telling you that everything sounds the same because it all measures the same. You need to take this advice with a large a pinch of salt. Many imparting such wisdom have at best a GCSE level of electronics understanding, but because they can seemingly talk-the-talk they can sometimes sound quite convincing. Doing a little research beyond their limited knowledge will generally expose those shortfalls so is always advisable.

The most appropriate subjects to have knowledge of to make the best decisions is not electronics, its biology and psychology.

The world greates scientists know not to put absolute trust the human senses which is why they test the way they do. You simply cannot trust your ears anymore than you can trust your brain and knowing this and taking account of it should help the decision making.

 

[Vladimir]

The Pio Stable Platter were really well sorted out players.

 

[MajorFubar]

@Davedotco

It would be very interesting to know if the outputs from the different transports passed the null test based on their outputs not their running error rate. With the error correction built into red book CDs as standard, I understand it takes a lot to go wrong before the output stream is 'unfixable' and cannot be reconstructed bit-perfectly, even if one reading mechanism/laser mechanism is reading at a higher error rate than another. Though that's bordering on the limit of my knowledge. I do know that even I've been right royally fooled into thinking the rips from two drives sounded different until I proved it to be an illusion. And I'm a skeptic.

 

[davedotco]

Just retelling an experience I had with Wadia in the late 90s.

Unlike many hi-end companies they considered themselves to be 'technology' based, so based their products on sound engineering.

The tests that I saw did not involve listening and relied on measuring the 'raw' data before error correction, not quite the same thing as we were discussing, but interesting I thought.

As an aside, the equipment would also show the effects of external vibration and was used in the development of their casework.

 

[MajorFubar]

The tests that I saw did not involve listening and relied on measuring the 'raw' data before error correction, not quite the same thing as we were discussing, but interesting I thought.

As an aside, the equipment would also show the effects of external vibration and was used in the development of their casework.

Yep indeed, wouldn't have minded seeing that myself, just for the experience really. Clearly there's a lot of logic that better transports and laser mechanisms which read the discs with less errors put less of a demand on the error correction software which has the uneviable task of rebuilding corrupt data back to its original state of bit-perfect intactness.

I always quite rated the Pioneer stable platter mechanisms, it didn't take a genius to work out that certainly the recipe was right for the mechanism to reduce read errors caused by vertical oscillations of the spinning disc. And even if one accepts that doesn't necessarily automatically translate itself into better sound quality (because of the inherrent error correction), you can't argue it's certainly no bad thing. So it always surprised me then how most Pioneer decks so equipped received fairly blasé (if not mediocre) reviews by the HiFi press. It seemed odd and unlikely that Pioneer would compliment this advanced reading mechanism with substandard DAC and analogue circuitry. Maybe it was because the mechanism was so expensive to build! Though I never heard one myself.

 

[davedotco]

In the UK at least, Pioneer players of the period were hampered by the companies mass market stance, they could and did do better but we saw little of their top end product in the uk.

The testing that I saw has stayed with my, some of the mechs were open so that the vibration of the disc was obvious to the naked eye, making the servos work that hard to read a disc did, and still does, make me pretty critical/sceptical of cd playback.

 

[Vladimir]

You can't listen to gear and music at the same time. You have to give up on one.

 

[keeper of the quays]

Im not convinced re expectation bias...

unless you do things to specifically remove them from the equation (which I wouldn't expect anybody to do in a casual situation such as buying a cd player - just for the record) then you can't rule it out, just the same with the placebo effect etc.

It's human nature, it's built in, there's certain things you can do to mitigate or try and rule them out, but if you don't, you can't rule them out full stop.  Just the way it is, and it's not just hifi this applies to, it's pretty much everything.

edit - just to add for those that like to make stuff up.  I'm not saying expectation bias *was* the reason you can hear the change, just that you *can't* rule it out when you have done nothing to rule it out.

i listened to a sacd last night..it sounded brilliant! I then realised it wasnt a sacd..said sacd in display window of player..i looked at manual online..went to menu on tv..(its a dvd/cd,sacd player) and realised my mistake..i was so sure i wss listening to sacd..i then compared it to cd version on other cd player that only plays cds..my bias fooled me..because i thought i was listening to sacd...no fool like a old fool.

 

[BIGBERNARDBRESSLAW]

Can I really hear a difference between two cheap CD transports?

No.

 

[andyjm]

@Davedotco

It would be very interesting to know if the outputs from the different transports passed the null test based on their outputs not their running error rate. With the error correction built into red book CDs as standard, I understand it takes a lot to go wrong before the output stream is 'unfixable' and cannot be reconstructed bit-perfectly, even if one reading mechanism/laser mechanism is reading at a higher error rate than another. Though that's bordering on the limit of my knowledge. I do know that even I've been right royally fooled into thinking the rips from two drives sounded different until I proved it to be an illusion. And I'm a skeptic.

Certain data storage and transmission systems are expected to have errors, and this is allowed for. At the lowest levels, Ethernet, hard disks, CDs all have errors, all the time. I remember reading somewhere that a 'good' CD has 220 errors per second at a physical read level.

Error correction fixes this. Redundant information stored or transmitted alongside the wanted data is used to identify and fix the errors.

A £25 CD drive will rip a CD in halfway decent condition without a single bit error after error correction. I have ripped CD after CD that have had 100% CRC matches (no bit errors) with the Accuraterip database, all without the drive having to do multiple seeks. I am sure the CDs had errors, but the correction fixed this. At approx 1.5Mb/s, a 30 minute CD has 4,050,000,000 bits of data, all without errors when ripped. Quite remarkable really.

The redbook CD spec was robust, and laser and servo technology has moved a long way since the 80s. CD errors are a red herring.

 

[Rups]

In the end I got an amp without an onboard DAC and went for a decent CD player. Chose an Audiolab 8200cd at an end-of-line price. Love the DAC functionality. And the sound is detailed and controlled. I dont agree with the many who find its sound above all to be "natural" like hearing music as it was performed. Sounds somewhat manipulated to me, especially on the filters the manufacturer appears to push most...if a cellist accidentally taps his bow against wood in the orchestra it is not just picked up but sounds like a drum. But this seems to be a trade off for detail and ambience, which I'm enjoying.

I also very much enjoyed all the above discussion which was fascinating. Thanks to everyone.

 

[NSA_watch_my_toilet]

In recording studios it happens a million times the engineer adjust an EQ knob, say treble, and hears he got it just right, but only to learn after hours of work the treble EQ function was defaulted (turned off). This is called expectation bias and to avoid it manufacturers put bright LEDs indicating if the EQ is on or off.

Maybe there is a difference between the CD transports you compared, maybe there isn't. There shouldn't be one unless the units are malfunctional or poorly designed. Unless you do a controlled test where you take away all your expectation biases, you can't know if what you heard was true or not. And no, "I wasn't expecting to hear a difference but I did, so I don't need to do controlled tests" is not a valid argument. You had an expectation, you were listening for differences like the studio engineer was turning the treble knob. You can't say you weren't listening for differences when you compared Cambridge CXC transport versus a Yamaha CD-N301.

Very good explaination dear Vladimir. Like often should I say.

 

[nopiano]

In the end I got an amp without an onboard DAC and went for a decent CD player. Chose an Audiolab 8200cd at an end-of-line price. Love the DAC functionality. And the sound is detailed and controlled. I dont agree with the many who find its sound above all to be "natural" like hearing music as it was performed. Sounds somewhat manipulated to me, especially on the filters the manufacturer appears to push most...if a cellist accidentally taps his bow against wood in the orchestra it is not just picked up but sounds like a drum. But this seems to be a trade off for detail and ambience, which I'm enjoying.

I also very much enjoyed all the above discussion which was fascinating. Thanks to everyone.

. Looks like a good choice. Hope you enjoy your music now! (A good thread too, I agree)

 

[Thompsonuxb]

You may receive quite a number of replies from certain members telling you that everything sounds the same because it all measures the same. You need to take this advice with a large a pinch of salt. Many imparting such wisdom have at best a GCSE level of electronics understanding, but because they can seemingly talk-the-talk they can sometimes sound quite convincing. Doing a little research beyond their limited knowledge will generally expose those shortfalls so is always advisable. 

So true....... *ROFL*