Review and Measurements of Totaldac d1-six DAC

[sajunky]

What?


Whatever it is, it is shown in the measurements as I showed you.

These are balanced interconnects so have high immunity to ground loops anyway.

And both 50 and 60Hz were present on FFT, leaking only from from the equipment under the test as you say, right?

I know, it is a proof for something more.

 

[JJB70]

Something to keep in mind is that the Audio DAC achieved technical maturity probably 25 - 30 years ago. We are not discussing some cutting edge esoteric concept here but a bread and butter commoditised tool the performance of which can be verified entirely by measurement. A lot of audio companies want us to believe that DACs ar are pushing the boundaries of science and comparable to achieving a working fusion power plant or faster than the speed of light travel or something. Who here would pay $10,000 for the latest high performance adjustable wrench because, you know like, it just adjusts so much better than last years model

 

[amirm]

And both 50 and 60Hz were present on FFT, leaking only from from the equipment under the test as you say, right?

The 50 Hz was certainly coming from the DAC since there is no such thing in the analyzer. Now what?

 

[sajunky]

The 50 Hz was certainly coming from the DAC since there is no such thing in the analyzer. Now what?

This also means that 60Hz came from a ground loop.

 

[amirm]

This also means that 60Hz came from a ground loop.

Not from the DAC which was operating at 50 Hz. But yes, APx555 has some 60 Hz leakage due to connection to the PC, etc.

Mains leakage is a fact of life in audio unfortunately. Many times though we have much bigger fish to fry which is the case with this DAC.

Also note that that my lab AC generator produces very clean power -- much better than what comes out of the wall in our house. So in that regard, this DAC is being given the benefit of the doubt versus your suggestion of using a transformer.

 

[AudioSceptic]

I’m not in the business of recording pianos, but I like listening to recordings of them. Are you suggesting that one can not have an opinion of what DAC sounds the most like actual instruments to them with making a test recording of a live event?

Yeah, the “your kind” comment says a lot about the level of discourse and debate on this forum.

(You might have noticed that I complained about that.)

What is happening if device A is shown to add considerable distortion but sounds better to you than device B, which measures far, far better? Can we still be measuring the wrong things after all this time, really?

Given that you have spent more on the DAC than many spend on their whole system, I'm curious what you compared it with. $13k covers a huge range, after all.

 

[Julf]

None of my personal sensory experiences are subjected to scientific verification, nor am I interested.

A great quote from a different context, but very applicable here: "Of course we should be empathetic to people who cling to irrational beliefs. But at the core we find "I'm ignorant, possibly emotionally immature, and intellectually lazy; I'm proud of it, and I'd much rather hang out with other ignorant and intellectually lazy people than to grow." That's hard to respect."

 

[THW]

im beginning to think that i actually should have doubled down on that particular comment and not bother to admitting my mistake given the level of obnoxious behaviour i’m seeing from certain people in this thread.

 

[sajunky]

Not from the DAC which was operating at 50 Hz. But yes, APx555 has some 60 Hz leakage due to connection to the PC, etc.

Mains leakage is a fact of life in audio unfortunately. Many times though we have much bigger fish to fry which is the case with this DAC.

Also note that that my lab AC generator produces very clean power -- much better than what comes out of the wall in our house. So in that regard, this DAC is being given the benefit of the doubt versus your suggestion of using a transformer.

I do agree to the most. However I suspect that AC generator could be a source of ground loops. It gives clean power, yes, but is also adding little bit more with regard of a ground reference. Clean power vs. wall socket is not the issue with most of equipment, but ground loops always are. It is why I think I didn't commit an offence suggesting isolating transformer.

 

[solderdude]

Since 100Hz and multiples come from rectified 50Hz it appears that most likely the 100Hz and multiples are coming from rectifier+regulator.
When it is a groundloop one would expect 50Hz to be there also and I don't see a 50Hz component peak.
The 60Hz component is a bit suspect but even if it is caused by a groundloop then it is evidence of a poor ground/reference(plane) design.

 

[Thomas savage]

im beginning to think that i actually should have doubled down on that particular comment and not bother to admitting my mistake given the level of obnoxious behaviour i’m seeing from certain people in this thread.

Our job here is to put forth the best example of rational debate as possible, I appreciated your self correction.

It's perfectly understandable for someone to believe in what they hear and find it very difficult to accept they might be faulty in their thinking regarding subjective opinions of audio replay.

There are significant psychological factors at play here , the direct (personal) confrontation that develops when dealing with opposite opinions rarely results in consensus. It tends to go along defensive lines like we have here.

In putting the best side of ' audio science' or objective measurement based rational forward we stand the best chance of being effective. The more aggressive one is the more defensive the opposing narrative becomes.

We must not forget we are talking to so many more people than just the contributors to the discussion and that's where we should keep our focus in moments like these.

 

[AudioSceptic]

Me too, and the same for Stereophile and HiFi News.

One thing that is so very telling is that there is little correlation between the subjective reports in Stereophile and JA's measurements, yet he never seems to question the hearing ability of the subjective reviewers, he just brushes aside these discrepancies.

 

[sajunky]

Since 100Hz and multiples come from rectified 50Hz it appears that most likely the 100Hz and multiples are coming from rectifier+regulator.
When it is a groundloop one would expect 50Hz to be there also and I don't see a 50Hz component peak.
The 60Hz component is a bit suspect but even if it is caused by a groundloop then it is evidence of a poor ground/reference(plane) design.

I wrote before, ground loops involve at least two components, it is incorrect to blame a single one.
As for 100Hz, yes, it comes from rectifiers, sure, even the input protection diodes.

 

[solderdude]

Input clamp diodes/TVS etc. will only do something when there are pulses across it that trigger them that substantially exceed the nominal voltage.
With a near perfect sinewave there won't be any activation at the nominal voltage... but you (should) know this already so why mention them ?

As I already mentioned... in case there is a groundloop in the measuring chain (which surely can exist) and the DUT shows it is susceptible for this the design of the DUT is poor.

 

[amirm]

What is happening if device A is shown to add considerable distortion but sounds better to you than device B, which measures far, far better?

Until he performs a controlled test, we don't what "sounds" better to him.

Let me cut through this. If he can tell TotalDAC sound better in a controlled test, I will give him $500.

Until then, I assure that he won't be able to tell the difference between Totaldac and any other DAC. If he could, then he would have picked up its flaws.

 

[amirm]

I wrote before, ground loops involve at least two components, it is incorrect to blame a single one.

You keep talking about ground loops, not me. I am careful to use the term leakage, not ground loop. Diagnosis of a ground loop requires further testing that is not on record.

 

[sajunky]

Input clamp diodes/TVS etc. will only do something when there are pulses across it that trigger them that substantially exceed the nominal voltage.
With a near perfect sinewave there won't be any activation at the nominal voltage... but you (should) know this already so why mention them ?

As I already mentioned... in case there is a groundloop in the measuring chain (which surely can exist) and the DUT shows it is susceptible for this the design of the DUT is poor.

Or a power generator. The same ground loop path. Is that make it clear to you?

 

[solderdude]

Is that make it clear to you?

What ?

 

[sajunky]

What ?

I guess, is not.

 

[Totoro]

As does the response by the rest of the forum to give him a gentle...Ummm...Hey there...to which he replied and then admitted error.

We are suggesting that, at a minimum, without matching the output levels by voltmeter, and doing the test blind...meaning not knowing which is playing, not blindfolded...one is influenced by so many kinds of bias that the results of this subjective experience is not reliable. Taking away the potential for bias through volume matching and blind testing

A great quote from a different context, but very applicable here: "Of course we should be empathetic to people who cling to irrational beliefs. But at the core we find "I'm ignorant, possibly emotionally immature, and intellectually lazy; I'm proud of it, and I'd much rather hang out with other ignorant and intellectually lazy people than to grow." That's hard to respect."

That’s brilliant!