Mark Levinson 519 measurements

[Jinjuku]

I see since yesterday you guys hobbled my account so it takes 5 minutes to even load a page. I log out and lightning fast again. Other accounts lightning fast, my account slow as a snail.

Shoot me your account credentials I'll test it out on my side.

 

[amirm]

That aside, you think that 0.0001% THD is a game changer?

No, I don't think it is a game changer. It is still half as much seeing how you listed them.

Note my spec is THD+N as well.

I assumed that. So you can't tell what is wrong with your spec that is not with theirs?

How about my other questions? Did you list the specs for the DAC chip or the measured your entire box?

Also the AKM4490 specs are based on utilizing the SRC/SDM faculties in the chip. All we use is the switched capacitor filter section. Which does happen to be the dynamic range bottleneck in the design. However the industry standard numbers are far beyond being good enough that the only think left that matters is what only industry insiders know. Trade secrets. I've shared some ane you should be grateful for this.

So you think their marketing department would not put the best number they can on the spec sheet and left it for you to create?

Regardless, please confirm where you got your numbers. Right now it seems you lifted them from the spec sheet for the DAC chip, not any real measurements of your own complete box.

 

[Mivera]

No, I don't think it is a game changer. It is still half as much seeing how you listed them.


I assumed that. So you can't tell what is wrong with your spec that is not with theirs?

How about my other questions? Did you list the specs for the DAC chip or the measured your entire box?


So you think their marketing department would not put the best number they can on the spec sheet and left it for you to create?

Regardless, please confirm where you got your numbers. Right now it seems you lifted them from the spec sheet for the DAC chip, not any real measurements of your own complete box.

The out of band specs all depend on the software modulator used. Also these specs were based on the SITO opamps installed in the Purestream. Almost everyone has switched to the Weiss.

If you read the datasheet the specs change with every sample rate. It's impossible to quote the specs with DSD bypass mode as they don't know the board layout, power supplied to the chip, or the analog filter design.

 

[amirm]

The out of band specs all depend on the software modulator used. Also these specs were based on the SITO opamps installed in the Purestream. Almost everyone has switched to the Weiss.

If you read the datasheet the specs change with every sample rate. It's impossible to quote the specs with DSD bypass mode as they don't know the board layout, power supplied to the chip, or the analog filter design.

So you are confirming that you gave us chip specs rather than measurements of your complete DAC?

And you don't know what is wrong with your THD+N spec that was not with Mark Levinson's?

 

[Mivera]

So you are confirming that you gave us chip specs rather than measurements of your complete DAC?

And you don't know what is wrong with your THD+N spec that was not with Mark Levinson's?

No like I said those were the results with the SITO opamps installed.

The chip specs don't mean anything with DSD bypass mode. All specs on the AK4490 datasheet are based on using the internal SRC/SDM section.

We basically use it for a traffic conductor, and mild DSD filter assist.

 

[amirm]

No like I said those were the results with the SITO opamps installed.

Let's put aside that you are giving numbers for one thing, but sell another. For the fifth or sixth time, do you know what is wrong with your THD+N number that is not with Mark Levinson's?

 

[Mivera]

Let's put aside that you are giving numbers for one thing, but sell another. For the fifth or sixth time, do you know what is wrong with your THD+N number that is not with Mark Levinson's?

I clearly stated on my website measured results depend on the opamps used. Measured results are only a big deal to very few forum based objectivists. The types who rarely buy anything good because they think $79 gets you the holy grail of digital audio.

The only client who bought a Purestream who even asked for measured specs was the man who sent you in the Uptone LPS-1 to measure. But I only sold him raw boards.

Oh and those specs are also at 0dbfs. Actually 18dB which is full power in balanced mode.

 

[amirm]

I clearly stated on my website measured results depend on the opamps used. Measured results are only a big deal to very few forum based objectivists. The types who rarely buy anything good because they think $79 gets you the holy grail of digital audio.

The only client who bought a Purestream who even asked for measured specs was the man who sent you in the Uptone LPS-1 to measure. But I only sold him raw boards.

I don't know how you keep acting as slippery as a freshly caught fish.

You put a set of numbers forward. Not us. I am just asking, if you know these numbers are, what is wrong with your number that is not with the Mark Levinson?

Here they are. ML 519:

Yours:

I will give you a strong hint. Here is the THD+N for Benchmark DAC3:

They also get it right.

 

[Mivera]

Obviously you're not reading my posts. I didn't put the output level after. But no big deal because no matter what any number says the sound of the Purestream won't change.

 

[amirm]

Obviously you're not reading my posts. I didn't put the output level after.

Not so. Every DAC has an amplifier. Just like any amplifier, its THD+N is proportional to level. Without level, THD+N is useless.

Now, who else omits that level? The chip companies! http://www.akm.com/akm/en/product/datasheet1/?partno=AK4490EQ

-112 db is 0.0002% that you give me.

What this says is that you have not measured the output of your DAC. Instead, you were giving us chip specs.

AKM does give us that detail later in the datasheet:

We see that quite a bit of conditions are stated there with these numbers. Bandwidth for example is limited and that reduces the noise (ultrasonics filtered out).

But no big deal because no matter what any number says the sound of the Purestream won't change.

Actually it can be a big deal. While it is very unlikely that you can better those numbers from AKM, you could have very well made them a lot worse. So much so that you could be creating audible distortions.

How do we analyze the sound? With full spectrum of THD, not dumb numbers. In that regard, ML, Benchmark and you are all presenting improper set of numbers.

That is why you never see me put forward numbers like this.

I show the spectrum which then allows us to use psychoacoustics to determine audibility of distortions.

In summary, the industry is bad. But you are far worse by copy and pasting chip specs and not even bothering to make any real measurements.

 

[Mivera]

Not so. Every DAC has an amplifier. Just like any amplifier, its THD+N is proportional to level. Without level, THD+N is useless.

Now, who else omits that level? The chip companies! http://www.akm.com/akm/en/product/datasheet1/?partno=AK4490EQ

View attachment 8495

-112 db is 0.0002% that you give me.

What this says is that you have not measured the output of your DAC. Instead, you were giving us chip specs.

AKM does give us that detail later in the datasheet:

View attachment 8496


We see that quite a bit of conditions are stated there with these numbers. Bandwidth for example is limited and that reduces the noise (ultrasonics filtered out).


Actually it can be a big deal. While it is very unlikely that you can better those numbers from AKM, you could have very well made them a lot worse. So much so that you could be creating audible distortions.

How do we analyze the sound? With full spectrum of THD, not dumb numbers. In that regard, ML, Benchmark and you are all presenting improper set of numbers.

That is why you never see me put forward numbers like this.

I show the spectrum which then allows us to use psychoacoustics to determine audibility of distortions.

In summary, the industry is bad. But you are far worse by copy and pasting chip specs and not even bothering to make any real measurements.

No it was the DAC analog out spec after the gainstage section. Once again I already acknowledged I forgot to put the output level on my online shop.

Once again you can clearly see the specs of the AK4490 are all based on what it needs to process. The more work it needs to do, the worse it performs. Noise makes it way to the outputs. When we don't utilize any of the onboard processing, and we power the chip alone with 6 separate LT3042's we can beat the datasheet measured specs going through the AK4490 SRC/SDM.

AKM doesn't provide any specs of when the chip is used in DSD bypass mode.

 

[Mivera]

The gainstage specs are much better than the DAC output. Look at this datasheet for accurate numbers of the Puregain board on its own.

Here's the OP1-bp specs. Op2 is even better.


http://www.weiss.ch/files/downloads/op1-bp/OP1-BP-Datasheet-R1.pdf

 

[amirm]

The gainstage specs are much better than the DAC output. Look at this datasheet for accurate numbers of the Puregain board on its own.

Here's the OP1-bp specs. Op2 is even better.

http://www.weiss.ch/files/downloads/op1-bp/OP1-BP-Datasheet-R1.pdf

Once you put that module in a *system* its performance changes. That is why the only measurement of value is that of the entire box, not for subcomponents.

People don't listen to the op-amp. They listen to the whole unit for which, you have no measurements.

 

[amirm]

Wise words from an industry icon:

"A full suite of tests as done by Stereophile with $50,000 worth of test equipment will show some minor differences, but your ears are a far better tool. Trying to use measurements to test audio equipment is about as smart as using measurements to test wines or food. Good luck with that. A mouse's brain literally has more computing power than every single computer ever made tied together. Nature is far, FARsmarter than people. Sorry to disappoint you there."

https://www.computeraudiophile.com/...an-a-cheap-dac/?do=findComment&comment=712961

Charley is a good engineer. He is conflicted though, knowing that he can't show marked improvement in high-end gear. So he repeats the same subjectivists PR line which can trivially to be shown to be wrong.

 

[Mivera]

Once you put that module in a *system* its performance changes. That is why the only measurement of value is that of the entire box, not for subcomponents.

People don't listen to the op-amp. They listen to the whole unit for which, you have no measurements.

Yes that's why we measured after. I can assure you the man who designed the output board understands how the OP2-BP needs to be implemented for best performance.

Repeating something false several times doesn't make it true. I told you where the measurements were taken from.

 

[Mivera]

Charley is a good engineer. He is conflicted though, knowing that he can't show marked improvement in high-end gear. So he repeats the same subjectivists PR line which can trivially to be shown to be wrong.

You better go onto that thread, slap down your resume, and teach him a thing or 2.

Don't leave out Jewel!!

 

[Blumlein 88]

You know I like to do sweeps for IMD. I haven't seen any halfway competent gear that had problems with THD if the IMD was good. Nor one that has higher THD than IMD.

 

[amirm]

You better go onto that thread, slap down your resume, and teach him a thing or 2.

I am banned on CA forum or it would have been my pleasure to have that discussion with him.

Remember, being a good engineer doesn't mean he has any experience with psychoacoustics or benefits of controlled testing.

BTW, I remember Charles from his AVS Forum posts. See how when measurements serve him well, he doesn't have issues with them:

Remember, a magician can fool everyday people a heck of a lot better than other magicians!

So don't cling to hero worshipping like this. Do a few controlled tests, including ones where nothing has changed, and then let me know if your "ear" is not the most blatant liar you know.

 

[Mivera]

I am banned on CA forum or it would have been my pleasure to have that discussion with him.

Remember, being a good engineer doesn't mean he has any experience with psychoacoustics or benefits of controlled testing.

BTW, I remember Charles from his AVS Forum posts. See how when measurements serve him well, he doesn't have issues with them:

View attachment 8500

Remember, a magician can fool everyday people a heck of a lot better than other magicians!

So don't cling to hero worshipping like this. Do a few controlled tests, including ones where nothing has changed, and then let me know if your "ear" is not the most blatant liar you know.

Once again slap down a stronger resume in the field. Only then are you worthy of debating with the industry greats. Owning a Harman only based dealership doesn't get you in the club.

 

[amirm]

Yes that's why we measured after. I can assure you the man who designed the output board understands how the OP2-BP needs to be implemented for best performance.

Who is "we?" Is your board a modification of this one? http://mirand-audio.dk/?product=ak4...ort-discrete-diffse-shield-pcm-filter-setting