Audiolab 6000CDT experience

[restorer-john]

Well I think there are probably differences between many CD players but rather small and more likely from the DACs than the mechanism. I have had two transports the Rotes RDD 980 and the Audiolab 6000 CDT they actually do sound quite different, even with the same DAC. The DAC difference is really quite huge. I had the matching Rotel DAC it was terrible, I was given an Arcam Black Box and that was worse. Moved onto a Marantz DAC which was far too bright but now have a Denifrips Ares II which is superb.

So you had the Rotel RDP/RDD pair from the early/mid 90s.

What exactly was 'terrible' about the Rotel RDP-980? And you had a Marantz D/A converter. Which one? The DA-94? WHat made you think it was "far too bright"?

 

[Deleted member 24508]

If it is "well documented", then share it. That once was the all point of this site, BTW.

No, no no. You are changing the story. We are talking about CD transports, not CD players. Of course, CD players may sound different, starting from their output voltage variations (at, say, 1.9Vrms Vs 2.5Vrms, the difference would be clearly audible).

What is the clear evidence you are talking about? For now, I've read nothing but anecdotes from you.

Observations are not anecdotes? Science is founded on observation, we knew thousands of years ago the earth travelled around the sun, we did not have to go there or measure it to know this, it was established by observation. It is impossible to measure what one person hears in comparison to another, the only possible method is by observation.

 

[Deleted member 24508]

So you had the Rotel RDP/RDD pair from the early/mid 90s.

What exactly was 'terrible' about the Rotel RDP-980? And you had a Marantz D/A converter. Which one? The DA-94? WHat made you think it was "far too bright"?

The RDP 980 was dull and lacked detail, the Marantz, I forget the number didn't have it long, was terrible for sibilance and sounded glassy rather like playing music in a greenhouse.

 

[Deleted member 24508]

If it is "well documented", then share it. That once was the all point of this site, BTW.

No, no no. You are changing the story. We are talking about CD transports, not CD players. Of course, CD players may sound different, starting from their output voltage variations (at, say, 1.9Vrms Vs 2.5Vrms, the difference would be clearly audible).

What is the clear evidence you are talking about? For now, I've read nothing but anecdotes from you.

The basic steps of the scientific method are: 1) make an observation that describes a problem, 2) create a hypothesis, 3) test the hypothesis, and 4) draw conclusions and refine the hypothesis.

 

[Mart68]

The observation needs to be made in controlled conditions though, otherwise it is prone to error and therefore any hypothesis drawn from it may also be in error.

If you think the DAC differences are huge from casual listening, then test that hypothesis by listening blind. If it is still easy to tell them apart then you are onto something. But the likelihood is you will find it either very difficult or impossible.

 

[VintageFlanker]

Observations are not anecdotes?

They certainly aren't "clear evidence" as you call it.

we knew thousands of years ago the earth travelled around the sun, we did not have to go there or measure it to know this, it was established by observation.

What the...?
How "we knew" exactly? Vast majority of people believed the other way around, and this by their everyday "observation". Geocentrism dominated for centuries, certainly not the opposite. Very few people theorised that wasn't the case and this has not been proved before 1513...

 

[Deleted member 24508]

The observation needs to be made in controlled conditions though, otherwise it is prone to error and therefore any hypothesis drawn from it may also be in error.

If you think the DAC differences are huge from casual listening, then test that hypothesis by listening blind. If it is still easy to tell them apart then you are onto something. But the likelihood is you will find it either very difficult or impossible.

With my recent DAC quite simply people have observed the difference without even being told it was a new DAC, it is unseen in my system.

 

[Deleted member 24508]

They certainly aren't "clear evidence" as you call it.

What the...?
How "we knew" exactly? Vast majority of people believed the other way around, and this by their everyday "observation". Geocentrism dominated for centuries, certainly not the opposite. Very few people theorised that wasn't the case and this has not been proved before 1513...

Greek astronomer Aristarchus of Samos is generally credited with being the first person to propose a Sun-centred astronomical hypothesis of the universe (heliocentric). At that time, however, Aristarchus’s heliocentrism gained few supporters and 18 centuries would then pass before Renaissance astronomer Nicolaus Copernicus produced a fully predictive mathematical model of a heliocentric system.

 

[restorer-john]

...The RDP 980 was dull and lacked detail...

Interesting. I use my old RDP-980 for TV and 2ch movie watching. I like it a lot. It's chock full of good quality components, twin transformers, excellent opamps and a pile of Rubycon back gates for good measure. A very nicely built vintage product.

Here's mine:

I'll run some tests on it over the coming weekend if I get a chance and post the results...

It uses IIRC an early AKM (Asahi Kasei Microsystems) switched capacitor sigma delta and a Crystal/Cirrus chipset.

An internet picture of the interior:

Service manaual date June 27, 1995 and I think they ran for a few years.

 

[rdenney]

Observations are not anecdotes? Science is founded on observation, we knew thousands of years ago the earth travelled around the sun, we did not have to go there or measure it to know this, it was established by observation. It is impossible to measure what one person hears in comparison to another, the only possible method is by observation.

Oh, please.

The issues are well-documented:

1. Any difference in level, even as small at 0.1 dB, will affect the subjective listening impression when comparing devices.

2. Any knowledge of which unit is being played will affect the subjective listening impression. That does not mean that we don't hear what we hear, it means that our interpretation of it goes through a range of conscious and unconscious filters that are biased by what we think we know of the devices under test.

This isn't a matter of observation versus anecdote, a common refrain from those who don't understand what those words mean to a scientist. We use the term "anecdotal data" to describe careful and controlled observations that nevertheless provide an insufficient sample size to assert a conclusion that can be transferred outside the test case. A doctor notes that a disease condition in Person 1 is improved by taking Med A. This is a careful and controlled observation to be sure that Med A really did improve Person 1's condition, and not Med B that the person was also taking, or the effect of Person 1 just being in a better mood. But it is anecdotal, because it says nothing about the likelihood of Med A improving the same condition in Person 2. A study of sufficient sample size to characterize a population requires careful and controlled observations, but it also requires something more: enough of those observations to demonstrate that the transferability of the effect to others is not mere chance.

You have not even demonstrated that your comparisons of CD players are careful and controlled--were they level-matched? Were you testing without knowing which device you were listening to (commonly known as blind testing)? If not, your own impressions should not even be reliable in reference to you (which requires care and controls), let alone transferrable to anyone else (which requires a sufficient sample size not to be anecdotal). That others heard the same effect without knowing what was playing isn't persuasive, because level-matching (using a millivolt meter and a test tone, not just "by ear") is the critical first step, and because you asked them to listen to something, which is already an indication that you made a change and desire approval. You are not being careful about this.

I own a range of CD players, including the vaunted (in its day) Magnavox CDB-650, a Tascam 401 (which has no audiophile credentials at all), a Cambridge CXC with various DACs, and a Naim. In the case of the Tascam, I also compared its internal DAC to various external DACs. These CD players range widely in price, new or used. I assert that I can't tell any difference between any of them. Now, what makes your observation more valuable than mine?

A transport that sounds different is introducing flaws in the data stream, but how would that happen without causing audible error artifacts such as dropouts or track-jumping? The transport isn't responsible for jitter--the DAC deals with that issue. Error survival either works or it doesn't. If there are data errors, these should be obvious because they will cause dropouts and tracking artifacts that are not subtle. But I can compare rips with the database accessed by Exact Audio Copy, and in nearly every case, the checksum on each track is exact--the files are essentially bit perfect even read at high speed in a $5 plastic computer drive. So, your observations not only don't demonstrate the care and controls they should for you to consider them reliable in your own case, but they violate what has been demonstrated analytically--that the same stream of bits delivered to a DAC will be the same no matter what the delivery device is.

Rick "whose perceived differences usually melt away with matched levels alone, not even requiring blind testing" Denney

 

[Deleted member 24508]

Interesting. I use my old RDP-980 for TV and 2ch movie watching. I like it a lot. It's chock full of good quality components, twin transformers, excellent opamps and a pile of Rubycon back gates for good measure. A very nicely built vintage product.

Here's mine:
View attachment 136720

I'll run some tests on it over the coming weekend if I get a chance and post the results...

It uses IIRC an early AKM (Asahi Kasei Microsystems) switched capacitor sigma delta and a Crystal/Cirrus chipset.

An internet picture of the interior:
View attachment 136719

Service manaual date June 27, 1995 and I think they ran for a few years.

 

[Deleted member 24508]

A number of reviews at the time commented on the value of the components it contained, just didn't suit my system I guess.

 

[Deleted member 24508]

Oh, please.

The issues are well-documented:

1. Any difference in level, even as small at 0.1 dB, will affect the subjective listening impression when comparing devices.

2. Any knowledge of which unit is being played will affect the subjective listening impression. That does not mean that we don't hear what we hear, it means that our interpretation of it goes through a range of conscious and unconscious filters that are biased by what we think we know of the devices under test.

This isn't a matter of observation versus anecdote, a common refrain from those who don't understand what those words mean to a scientist. We use the term "anecdotal data" to describe careful and controlled observations that nevertheless provide an insufficient sample size to assert a conclusion that can be transferred outside the test case. A doctor notes that a disease condition in Person 1 is improved by taking Med A. This is a careful and controlled observation to be sure that Med A really did improve Person 1's condition, and not Med B that the person was also taking, or the effect of Person 1 just being in a better mood. But it is anecdotal, because it says nothing about the likelihood of Med A improving the same condition in Person 2. A study of sufficient sample size to characterize a population requires careful and controlled observations, but it also requires something more: enough of those observations to demonstrate that the transferability of the effect to others is not mere chance.

You have not even demonstrated that your comparisons of CD players are careful and controlled--were they level-matched? Were you testing without knowing which device you were listening to (commonly known as blind testing)? If not, your own impressions should not even be reliable in reference to you (which requires care and controls), let alone transferrable to anyone else (which requires a sufficient sample size not to be anecdotal). That others heard the same effect without knowing what was playing isn't persuasive, because level-matching (using a millivolt meter and a test tone, not just "by ear") is the critical first step, and because you asked them to listen to something, which is already an indication that you made a change and desire approval. You are not being careful about this.

I own a range of CD players, including the vaunted (in its day) Magnavox CDB-650, a Tascam 401 (which has no audiophile credentials at all), a Cambridge CXC with various DACs, and a Naim. In the case of the Tascam, I also compared its internal DAC to various external DACs. These CD players range widely in price, new or used. I assert that I can't tell any difference between any of them. Now, what makes your observation more valuable than mine?

A transport that sounds different is introducing flaws in the data stream, but how would that happen without causing audible error artifacts such as dropouts or track-jumping? The transport isn't responsible for jitter--the DAC deals with that issue. Error survival either works or it doesn't. If there are data errors, these should be obvious because they will cause dropouts and tracking artifacts that are not subtle. But I can compare rips with the database accessed by Exact Audio Copy, and in nearly every case, the checksum on each track is exact--the files are essentially bit perfect even read at high speed in a $5 plastic computer drive. So, your observations not only don't demonstrate the care and controls they should for you to consider them reliable in your own case, but they violate what has been demonstrated analytically--that the same stream of bits delivered to a DAC will be the same no matter what the delivery device is.

Rick "whose perceived differences usually melt away with matched levels alone, not even requiring blind testing" Denney

So an observation of no difference is more reliable or valuable than one of difference. Sorry but my Audiolab is markedly different to my Naim with the same DAC, take it or leave it makes no difference to me.

 

[Deleted member 24508]

Greek astronomer Aristarchus of Samos is generally credited with being the first person to propose a Sun-centred astronomical hypothesis of the universe (heliocentric). At that time, however, Aristarchus’s heliocentrism gained few supporters and 18 centuries would then pass before Renaissance astronomer Nicolaus Copernicus produced a fully predictive mathematical model of a heliocentric system.

So it took 18 centuries for measurement to catch up with observation. I rest my case.

 

[rdenney]

So an observation of no difference is more reliable or valuable than one of difference. Sorry but my Audiolab is markedly different to my Naim with the same DAC, take it or leave it makes no difference to me.

If it's so different, why are you unwilling to back it up with a controlled, blind test? I know it's a bit of work to do that right, but on the other hand, this is a hobby and that's part of it.

I didn't say my observation of no difference is any more reliable than your observation of difference. But it's certainly no less reliable, either. So, what mechanism do sensible people use to resolve that? Pissing distance? Breast-beating? Years of experience? Background as a musician? Comparing your system to mine, or your ears to mine? Let's stipulate that none of that is likely to persuade me any more than it will persuade you. Saying "take it or leave it" is easy, but empty--I will leave it. But really so should you.

The observation that the earth is round or whatever was made qualitatively, and thus was not persuasive to everyone for quite a long time. Those who were not persuaded were thought to be backwards, but in fact they were merely and properly skeptical. (I'm following your story that observations were merely qualitative, as a thought experiment, but in fact the motions of the solar system were regular and could be interpreted approximately correctly even with the imprecise measurements of ancient times.)

There were lots of other observations of the natural world that were made qualitatively, too. A few turned out to be correct when "measurements caught up" but most turned out to be the myth and lore that any later analysis would have predicted. So, what were the ancient skeptics to believe? How should they have known that the earth is round or revolves around the sun or whatever but that disease is not caused by out-of-sorts humours and treatment isn't served by blood-letting?

Rick "appeal to authority does not persuade me" Denney

 

[Deleted member 24508]

If it's so different, why are you unwilling to back it up with a controlled, blind test? I know it's a bit of work to do that right, but on the other hand, this is a hobby and that's part of it.

I didn't say my observation of no difference is any more reliable than your observation of difference. But it's certainly no less reliable, either. So, what mechanism do sensible people use to resolve that? Pissing distance? Breast-beating? Years of experience? Background as a musician? Comparing your system to mine, or your ears to mine? Let's stipulate that none of that is likely to persuade me any more than it will persuade you. Saying "take it or leave it" is easy, but empty--I will leave it. But really so should you.

The observation that the earth is round or whatever was made qualitatively, and thus was not persuasive to everyone for quite a long time. Those who were not persuaded were thought to be backwards, but in fact they were merely and properly skeptical. (I'm following your story that observations were merely qualitative, as a thought experiment, but in fact the motions of the solar system were regular and could be interpreted approximately correctly even with the imprecise measurements of ancient times.)

There were lots of other observations of the natural world that were made qualitatively, too. A few turned out to be correct when "measurements caught up" but most turned out to be the myth and lore that any later analysis would have predicted. So, what were the ancient skeptics to believe? How should they have known that the earth is round or revolves around the sun or whatever but that disease is not caused by out-of-sorts humours and treatment isn't served by blood-letting?

Rick "appeal to authority does not persuade me" Denney

So when observation is proven to be correct we can dismiss it as a good guess?

 

[rdenney]

So when observation is proven to be correct we can dismiss it as a good guess?

It depends on the basis for that observation. A careful and controlled observation might still not be transferable to others. And it might still be based on something wrong in the testing protocol that should be rooted out. But it invites further testing and analysis, and that testing and analysis knows what effect it's trying to expose.

But without that care and control, there's nowhere to go but to either pissing contests or appeals to magic. What hypothesis do you propose? I've heard them all--the DAC chips, the content of the wire, the transformer, the op-amps (or the avoidance of op-amps), the external power supply, the interconnects, the rest of the system, the ears, the room, the phase of the Moon, "jitter" (which is a word most use without knowing what it is), speaker wires, the presence of green dry-erase marking on the CD, the presence of little magnets near the device, the large brick on the top of the case, the box full of dirt into which a wire is laid, lifting the speaker wires off the floor, and on and on. Careless observations may be false, but even if true don't open the door to understanding why they are true, and don't prevent the effect from leading to all manner of charlatanism.

Rick "science is not the easy button" Denney

 

[ea666]

Bought the Audiolab 6000cdt over the weekend. Should arrive tomorrow and looking forward to see how it sounds with the Gustard X16 and the topping D90SE when it arrives.

 

[Deleted member 24508]

It depends on the basis for that observation. A careful and controlled observation might still not be transferable to others. And it might still be based on something wrong in the testing protocol that should be rooted out. But it invites further testing and analysis, and that testing and analysis knows what effect it's trying to expose.

But without that care and control, there's nowhere to go but to either pissing contests or appeals to magic. What hypothesis do you propose? I've heard them all--the DAC chips, the content of the wire, the transformer, the op-amps (or the avoidance of op-amps), the external power supply, the interconnects, the rest of the system, the ears, the room, the phase of the Moon, "jitter" (which is a word most use without knowing what it is), speaker wires, the presence of green dry-erase marking on the CD, the presence of little magnets near the device, the large brick on the top of the case, the box full of dirt into which a wire is laid, lifting the speaker wires off the floor, and on and on. Careless observations may be false, but even if true don't open the door to understanding why they are true, and don't prevent the effect from leading to all manner of charlatanism.

Rick "science is not the easy button" Denney

All true.

 

[pagan84]

6000CDT has 44.1kHz on outputs (usually cheap Blurays / Xbox give 48kHz) and for £379 there is a chance it is properly clocked and buffered
I'm happy with mine, tempted to say it is crystal clear but probably music from my PC via Fiio K5pro would sound the same (don't know, haven't tested that). Cheers!