KTB vs Topping E30 listening tests

[PierreV]

I think that if one wants to be certain there's an audible difference, accurate level matching is the way to go, especially if one wants to make a somewhat valid "public" point. As far as I am concerned, since I don't hear significant differences in my blind tests (except for one device, the analog out of the Chromecast Audio), I don't bother. My hobby is listening to music, not testing extensively.

If one doesn't hear a difference, even if it could be because the "inferior" dac happens running at a bit higher volume, is that a problem? If the worse dac needs a couple of dB more to sound as good as the better dac, who cares from a practical point of view?

And, assuming FR is what mostly defines our preferences, I am still not sold on the idea of level matching at some specific semi-arbitrary frequency.

But yeah, if sharing subjective preference results is one's cup of tea, be as meticulous as possible in terms of experimental methods.

 

[daftcombo]

Who needs to level match?

Just play sometimes A a bit louder than B, sometimes the contrary (50% - 50%) and see, at the end, if A or B has better results in the ABX.

 

[solderdude]

Do you guys really think volume matching is that critical in this case? I could see if this were an instant switch box A/B comparison, but when one dac is going to have to be disconnected and the other switched in? Could a person not "fool" their brain by simply turning the volume down before switching the other dac in and then turning it up to a suitable level once the new dac is connected? It seems to me like it would be OK for the listener (who should be blind-folded afaic) to be able to request volume increases or decreases while listening. As long as he's not aware of which dac is plugged in I don't think it would impact the test results...

When the output levels of the DACs are very similar (which they are) 2.05V KTB and 2.15V (difference of 0.4dB in favor of the E30) only blind testing (not knowing which one is connected) and turning the volume down each time and up again (not mute and unmute) may give good enough results.
When switching the 0.4dB difference will be audible.

 

[Sgt. Ear Ache]

Who needs to level match?

Just play sometimes A a bit louder than B, sometimes the contrary (50% - 50%) and see, at the end, if A or B has better results in the ABX.

yeah that's what I'm getting at. If the volume levels are set essentially by ear without knowing which dac is which then each dac has an equal chance of benefiting from louder volume...and the time between listening (while one is disconnected and the other hooked up) would pretty much remove any really tiny volume differences as a big issue.

A critical thing though would be for the test to be done several times (meaning several separate test sessions). The larger the sample size the better to rule out dumb luck...

 

[Pdxwayne]

Thank you all for the suggestions!

Yes, let a helper switch without the need to do volume matching each time would be much easier. All the helper needs to do is to keep note of A or B being switched to. After each supposed switch, I would turning volume all the way down first via digital volume control (via node2i variable out), then turning up the volume.

As the DAC have different output voltage, doing instance switch testing would tend to favor the louder one, which would be toward the e30.

I also just remember that after firmware update (updated on Nov 19 from default version it came with) on my KTB, the imbalance and sharpness issues that I previously observed on KTB are gone. I mentioned this in the L30 thread where I complained about not able to enjoy my headphones. Could updating firmware changes audio quality of a dac? I am mentioning this because I managed to listen to KTB with speakers system for a short while, kind of loud, yesterday, before being shut down by my wife. : ) I didn't observe the sharpness I heard before, which I heard prior to firmware update.

 

[Pdxwayne]

I spent ~10 minutes tonight trying to do simple sighted comparisons. I found unplugging and reconnect the coaxial cable and RCA cables too cumbersome. : (

 

[raif71]

I spent ~10 minutes tonight trying to do simple sighted comparisons. I found unplugging and reconnect the coaxial cable and RCA cables too cumbersome. : (

I'm not at all surprised. I did try some ABX of gears but eventually I just retired to just enjoy listening to music. However, don't let me de-track you from pursuing to do what you set out

 

[Pdxwayne]

I'm not at all surprised. I did try some ABX of gears but eventually I just retired to just enjoy listening to music. However, don't let me de-track you from pursuing to do what you set out

I think for source, I will just do coaxial out from node2i to KTB and toslink out from Node2i to e30. Then I wouldn't need to switch coaxial cable like before.

What I would need is a well measured preamp to do easy RCA switch to L30. Maybe will wait for Topping preamp.....

 

[ZenTraveler]

For my experience of doing a/b testing, my mind that time is open to both possibilities. There is difference between two DAC or there is no difference. My motivation to do the testing is curiosity what will be the result.

As I don't have any gadgets to get accurate volume matching, I just use sound meter app on my phone to volume match it then do a/b testing. I couldn't notice any difference of sounds even after listening to plenty of songs.

My point is to approach the test with objective mind. Start with simple test, if you still convinced you can hear difference then only go with more elaborate test. If you can't hear any difference then you just saved your time and money.

 

[BDWoody]

I think for source, I will just do coaxial out from node2i to KTB and toslink out from Node2i to e30. Then I wouldn't need to switch coaxial cable like before.

What I would need is a well measured preamp to do easy RCA switch to L30. Maybe will wait for Topping preamp.....

If you can tell a difference, then switch the digital source as well. It is an even bigger pain without a good preamp, no doubt.

It's good to see you go through the hassle!

That didn't sound quite right, but you know what I mean...

 

[Pdxwayne]

If you can tell a difference, then switch the digital source as well. It is an even bigger pain without a good preamp, no doubt.

It's good to see you go through the hassle!

That didn't sound quite right, but you know what I mean...

Unfortunately, KTB only take USB or coaxial. So, can't switch to toslink....Thinking more about it, I think it might be difficult to convince people even I heard a difference as they might say it is due to differences between coaxial vs toslink.... : (....But I might hear no difference anyway. : )

 

[BDWoody]

Unfortunately, KTB only take USB or coaxial. So, can't switch to toslink....Thinking more about it, I think it might be difficult to convince people even I heard a difference as they might say it is due to differences between coaxial vs toslink.... : (....But I might hear no difference anyway. : )

Start with what you can do, and tighten it up as needed.

I've not done a scientifically valid test suitable for peer review, but I stopped hearing differences long before that. If I had, or ever do, I would keep working towards getting it as tight as possible until they're was no place left for the differences to hide.
Then I'd publish and duck... Realizing it was still likely a setup error unless something was broken.

 

[Sgt. Ear Ache]

Unfortunately, KTB only take USB or coaxial. So, can't switch to toslink....Thinking more about it, I think it might be difficult to convince people even I heard a difference as they might say it is due to differences between coaxial vs toslink.... : (....But I might hear no difference anyway. : )

I doubt many of us would have that concern lol...

 

[Sgt. Ear Ache]

Start with what you can do, and tighten it up as needed.

I've not done a scientifically valid test suitable for peer review, but I stopped hearing differences long before that. If I had, or ever do, I would keep working towards getting it as tight as possible until they're was no place left for the differences to hide.
Then I'd publish and duck... Realizing it was still likely a setup error unless something was broken.

yeah any blind tests I've done haven't had to be very stringent in order to convince me that what I thought I was hearing was just in my imagination.

 

[Pdxwayne]

I do wonder about the rest of the setup....

I am assuming using Topping L30 headphone amp for headphones testing would be a good choice. But what headphones would be a good enough choice? The most expensive headphones I have is Philips x2hr. Good enough?

For comparison using normal stereo amp and speakers, what combo would be most revealing? Use the highest sinad amp and speakers would be the way to go, I supposed. But how good is good enough?

 

[Sgt. Ear Ache]

I do wonder about the rest of the setup....

I am assuming using Topping L30 headphone amp for headphones testing would be a good choice. But what headphones would be a good enough choice? The most expensive headphones I have is Philips x2hr. Good enough?

For comparison using normal stereo amp and speakers, what combo would be most revealing? Use the highest sinad amp and speakers would be the way to go, I supposed. But how good is good enough?

well, you're attempting to confirm distinctions you already think you've identified right? What did you use to accomplish that?

 

[Pdxwayne]

well, you're attempting to confirm distinctions you already think you've identified right? What did you use to accomplish that?

My statement about KTB is sharper was based on my observations early on when I only have the KTB, before firmware update. I made a thread for it even. See https://www.audiosciencereview.com/...sound-different-than-khadas-tone-board.17177/.

I also made comments in L30 thread about my headphones sounding sharp and once I updated the firmware in KTB in late November, it is not that sharp anymore. See https://www.audiosciencereview.com/...ne-amplifier-review.15226/page-97#post-574028

Thus, I would say it will be harder to compare now without a good enough, reveling, rest of the setup.....

 

[Sgt. Ear Ache]

OK well this discussion arose in the E30 thread with claims about the KTB being better at detail retrieval than the E30...

 

[BDWoody]

Thus, I would say it will be harder to compare now without a good enough, reveling, rest of the setup.....

In other words... Effectively the same, based on your use, in your space, with your current equipment...?

That's what I found too.

 

[Pdxwayne]

In other words... Effectively the same, based on your use, in your space, with your current equipment...?

That's what I found too.

The only time I did sighted comparison was last night for 10 minutes with my headphones and L30. I would agree that it is hard to know without volume matching. Going louder with E30, it can go harsh too. I intend to use your suggestion of matching voltage to do equal volume comparison.