Serious Question: How can DAC's have a SOUND SIGNATURE if they measure as transparent? Are that many confused?

[Robin L]

That would depend on how the tube buffer is designed and how much purpose designed 'tube goodness' is added, whether or not it reaches audible levels.
Cathode followers (buffers usually are just this) working on 200V rails usually don't add much, if any, tube goodness with just 2V AC voltage. It is basically linear in that range so little harmonics will be added.
When substantial amplification followed by attenuation to line level again or low power supply voltages were used on the anode you may get more 'tube goodness' out of it.

I'd note the "starved tube" microphone preamp designs with the line level tube output deliberately designed to have soft limiting kick in early.

 

[pkane]

Repeated null from 2 measurements on d30, and 2nd comparison between both dacs. This time 1khz tone used .

A simple fact with modern dsd dac chips is that they changed digital filters embedded each generation. They aren't completely the same. Now we still have to ask if they are supported by a similar peripheral. In most cases, no. So DAC as a whole unit is unlikely sound the same. They can be close, however, especially with those Chinese brands since they use textbook-style designs all over. Topping, in its own case, like boutique parts such as MELF resistors they put in D70, and huge amount of tantalum caps everywhere despite some locations doesn't benefit from it. Those are really eye-catching in flyers. "Beefy" in the eyes of amateurs.

China's market is a bit different. Most people you see online build their own PC. They might not know electrical engineering well but will be familiar with wima/tantalum/oscon etc as they used to or are currently heavily used in PC components. Topping picks up that sensation very well.

You're using only 16 bits. It looks like you're limited by the captured resolution and, the noise and distortions of the interface, it's not a fair comparison of the two DACs. This is the discussion we had earlier this year: your measurement interface (ADC) should be at least as good, or preferably, much better than the devices you're trying to measure: lower noise, lower distortion.

The second comparison seems to be clipping the interface. The input is too high for it to handle.

 

[pkane]

1) I use universal setting for both devices so there is a fair base for comparison. They both playback 16 bit and I record 16bit. Volume matched. Why 16 bit? That's what my test tone is, 16/44.1. So if this terrible ADC can pick up something, it is not delusional for sure.
2) I took 3 files. Two from topping, then one from 503 mod. So both figures captured all 3 recordings. If if you think the 2nd comparison had clipping, the 1st had it too, but you didn't point it out. That's probably because the software wanted to try alternative matching algorithm when I compare topping with 503. Take it with a grain of salt if you don't like it, despite it's your software.
3) There is no clipping. I had been checking levels and clipping indicators carefully.

I would suggest people just do their own test. Who am I to trust anyway. Some on this forum even don't give credit to manufacturer datasheets.

Clipping appears as a lot of harmonics and other distortions at a fairly high level. Second harmonic is at -50dB, third not much below that:

If there was no clipping, then both DACs are well below the capabilities of modern DACs in THD (or, more likely the interface is).

Here's D30 measured by Amir (red). See the difference?

 

[solderdude]

opamp rolling done with an AP:

https://www.audiosciencereview.com/...-op-amps-in-topping-d10-dac.4576/#post-102460

Do different opamps in a buffer stage really matter ?
Sure there are measurable difference but there is something like audible threshold.

 

[mansr]

1) I use universal setting for both devices so there is a fair base for comparison. They both playback 16 bit and I record 16bit. Volume matched. Why 16 bit? That's what my test tone is, 16/44.1. So if this terrible ADC can pick up something, it is not delusional for sure.

What could capturing at 16/44.1 possibly show? Even if the DAC were limited to 16-bit output (it isn't), you should still capture at 24-bit.

2) I took 3 files. Two from topping, then one from 503 mod. So both figures captured all 3 recordings. If if you think the 2nd comparison had clipping, the 1st had it too, but you didn't point it out. That's probably because the software wanted to try alternative matching algorithm when I compare topping with 503. Take it with a grain of salt if you don't like it, despite it's your software.

There are obviously three different D30 files here, as evidenced by the length info displayed under the filename. What are we actually looking at here? Whatever it is, there are clear signs of errors in both images. In the first, there is way too much spread around the 1 kHz peak, and the second clearly has clipping. Both have a weird noise hump around 16 kHz.

3) There is no clipping. I had been checking levels and clipping indicators carefully.

In that case, your clipping indicators are faulty or you've screwed up in some other way to cause that much distortion.

What ADC are you using for this?

 

[PenguinMusic]

Hi guys,

Now I am beyond "confused". I am totally puzzled.

Me, I never even saw a tool that allows to measure sound.
Here is how I imagine it :
- I take a cable (as a cable makes no difference, any cable will do).
- I plug one end of the cable in the device output.
- I plug the other end in the measurement tool input.
- I then feed the device with a signal and the measurement tool tells me what comes out.
- Assuming there's a volume control or a button that changes the "filters", I make sure to have the same settings.

I may be naive, but me, I assumed that there's no mystery or procedure and thatI should get same results whatever device I use to measure.

As I said, totally puzzled :-(

 

[solderdude]

This is called an Audio analyzer.
using it properly is essential. It should be better than the best device you want to analyze.

Another way of testing is null testing but is a bit tricky because both time and amplitude differences come out as amplitude differences so need to be analyzed correctly.

These tests and the test results is what ASR is all about.

 

[pkane]

Ethan Winer was doing his cable test with a sansa clip as a source which doesn't do 24bit. Nobody questioned that. I think it is time to stop asking for 24 bit. Quote on 16bit vs 24bit.

As for clipping, there is no such thing. If you have to find a fault in me, probably the only one is that I shouldn't respond to the thread.

I am not going to respond to this topic any further.

There's no reason to get upset when someone is asking questions about your test procedure. It is better to do a 24 bit ADC recording, even when testing 16-bit DACs. It is also reasonable to record at a higher sampling rate than the DACs. It is important to use a higher quality ADC than the DACs you are trying to measure. All of these are normal, reasonable expectations in testing, especially since you are trying to analyze low-level differences between these devices. Your measuring device, the ADC, should have lower noise and distortion than the devices you're measuring. If it's not, your results are likely measuring the interface, instead.

There's significant distortion in your second 1kHz capture. Clipping or not, this is not normal and needs to be explained if this is really what the DAC produced. It shows a problem with the device, the signal, or the test procedure.

Ethan's null tester is an analog device, so it works with whatever source you feed it. Since it was used to test for differences between cables, there is absolutely no reason to argue about the quality of the audio source. That's not what was being measured, so any audio signal would work for this test. It could just as well be audio from an AM radio, and the result would still be just as valid.

 

[cjm2077]

Ethan Winer was doing his cable test with a sansa clip as a source which doesn't do 24bit. Nobody questioned that. I think it is time to stop asking for 24 bit. Quote on 16bit vs 24bit.

As for clipping, there is no such thing. If you have to find a fault in me, probably the only one is that I shouldn't respond to the thread.

I am not going to respond to this topic any further.

Part of my job in the past has been developing test procedures and calibration processes for electrical hardware. You can't measure something accurately by using a piece of equipment with equivalent error. You have to use test equipment that is an order of magnitude better in terms of error in order to know if the error is coming from the equipment or from the device under test. You are not doing that. You don't even seem to know the comparative errors of these devices. What is the effective number of bits of that 16 bit ADC you are using?

 

[mansr]

What is the effective number of bits of that 16 bit ADC you are using?

A simple yet potentially revealing test is to record the DAC playing 16-bit dither noise as well as pure silence. If there isn't a clear difference in noise level between these recordings, either the DAC or the ADC is crap.

 

[PenguinMusic]

This is called an Audio analyzer.
using it properly is essential. It should be better than the best device you want to analyze.

Another way of testing is null testing but is a bit tricky because both time and amplitude differences come out as amplitude differences so need to be analyzed correctly.

These tests and the test results is what ASR is all about.

Hi,

Just to have an idea... What does such a baby cost approximately ?

 

[mansr]

Just to have an idea... What does such a baby cost approximately ?

If you have to ask, you can't afford it.

 

[Robin L]

Hi,

Just to have an idea... What does such a baby cost approximately ?

Less than Loudspeakers and Turntables being shilled over at Stereophile Planet.

 

[mansr]

Less than Loudspeakers and Turntables being shilled over at Stereophile Planet.

That could still be more than the GDP of a small country.

 

[solderdude]

Hi,

Just to have an idea... What does such a baby cost approximately ?

An audio analyzer ?
Something to use for Nulling ?
What resolution do you want ?
What frequency range ?
Amateur level or professional level ?
In case of the latter it requires quite a learning curve.
What kind of measurements are you looking for ?

You can analyze things with equipment costing anything between several hundred $ up to the price of a very decent sportscar.

 

[cjm2077]

Hi,

Just to have an idea... What does such a baby cost approximately ?

Serious test equipment is seriously expensive. Audio Precision makes some of the best units, and they're usually 20k+.

 

[PenguinMusic]

Hi,

OK. So it is not equipment than everyone can afford..
But it seems a lot of people in here have one or have access to one.
Nice

 

[Wombat]

Placing trust in people who really know their stuff and accepting the advice freely offered would significantly unclutter threads. Their answers can usually be easily found to be corroborated here or elsewhere.

Asking for clarification is OK. Asking to be proven wrong not so OK.

Burden Of Proof.

 

[PenguinMusic]

Placing trust in people who really know their stuff and accepting the advice freely offered would significantly unclutter threads. Their answers can usually be easily found to be corroborated here or elsewhere.

Asking for clarification is OK. Asking to be proven wrong not so OK.

Burden Of Proof.

Hi,

I can get that. Especially as a lawyer I have a hint of knowledge about burden of proof

But it seems that when some people give proof with numbers and measurements, it is "Here is proof".
And when some other people come up with measurements and numbers stating the opposite, it is "Your measurement procedure is biased => your equipment is not enough => you have no knowledge".

Under these circumstances, it is really difficult to tell who "really knows it's stuff" and depending on results of measures given by one or the other is highly questionable.

So much for science...

 

[Voo]

my 1st dac 20+ yrs ago I could hear a very slight difference. it was a msb link dac added to a yamaha avr with adcom amp. today, I have a few dacs in different rooms and I just dont really care anymore as long as they work and sound good. I will admit its nice to have multiple systems...none of them sound the same.