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Crude Test - What do you get when upgrading your headphone amplifier? Is it all a placebo?

TylerT

Member
Joined
May 17, 2024
Messages
13
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Location
Alberta, Canada
My current set-up: iPhone 15 Pro Max => USB C Data Cable => Fiio BTR15 => Hart 4.4mm Balance Cable => Hifiman Ananda Nano

I’ve recently upgraded my DAC/amp combo from a Fiio BTR15 to a Fiio K7. The main reason for this upgrade was the higher power output. The K7 uses two THX AAA 788+ Amps, outputting L+R≥2000mW+2000mW(32Ω /THD+N<1%). The BTR15 has a power output of L+R≥340mW+340mW (32Ω,THD+N<1%). They have different DACs, but I don’t believe DACs are of low enough quality to make a difference.

I upgraded because I heard planar magnetics will benefit from the increased current. I am not very knowledgeable about audio science, but I’ve read arguments from both sides about whether it matters. My line of thinking was that even if the Ananda Nanos do not benefit from the higher power, higher-quality amplifiers must have a better implementation, lower noise, or some other reason for an increase in audible performance. Why else would anyone upgrade their amp or spend thousands if there was no audible benefit to higher power and better quality amps once the power requirement was met?

Additional specs for the K7 and BTR15:
K7: DAC: AK4493S*2 , USB: XMOS XUF208 , Volume IC:NJU72315 * 2
BTR15: DAC: ES9219MQ * 2 ,USB: XMOS XU316, Bluetooth decoding: QCC5125

After receiving my K7, I promptly hooked it up to my iPhone and was very pleased with the results. It sounded like it had more bass, fullness, and clarity. As a scientific person, I wanted to validate that it wasn’t a placebo effect. When I compared the BTR15 with the K7, I used the same iPhone playing the same song segment, cable, and headphones, and tried my best to ensure that levels matched.

Since I did not have an objective tool to measure level outputs, I tried setting the K7 slightly lower than the BTR15. To my surprise, after waiting in silence to reset my hearing perception, the BTR15, with its ever so slightly louder volume, sounded more bassy, full, and clear. I repeated this experiment many times, trying my best to match the levels while ensuring I knew which one had the slightly higher level. I also repeated this with varying volumes. The DAC/amp outputting the slightly louder volume sounded better in all instances.

After doing these tests for a few hours, I realized they both sounded identical. I even took small breaks in between to recover from hearing fatigue. Perhaps the difference lies not in the bass, highs, or fullness but in resolution. My theory was that the K7 could be more ‘revealing’ or ‘resolving’ than the BTR15, possibly due to better implementation of chips, less noisy amplification, etc. I could only think of testing this through lossy/lossless ABX tests. I am normally only able to pass the 96 kbps MP3 vs lossless test on this website: https://abx.digitalfeed.net/list.html, and cannot reliably pass the 256 kbps Apple AAC test. Perhaps with the new K7, I will be able to better hear the audible differences between high-quality lossy and lossless.

When performing the ABX tests, I used my iPhone 15 Pro Max => USB C Cable => K7/BTR15 => 4.4mm Balanced Cable => Ananda Nano. I used the iPhone because iOS does not resample audio before sending it to the external DAC. With Windows or MacOS, Chrome does not have an ‘exclusive mode’, and therefore, I felt that it affected the quality and reliability of the ABX test. I performed multiple ABX tests at different volumes for the next few hours. I concluded that the K7 did not, in fact, resolve detail more accurately than the BTR15. In fact, after listening and comparing both the K7 and BTR15 for an extended duration, I further felt that there was no audible difference in quality between the two.

Testing Conclusion
The Fiio BTR15 should be in a totally different class than the K7, with the K7 supposedly offering a much better listening experience than the BTR15; however, they sounded identical to me. If planar magnetic headphones benefit from higher current, it is not audible (at least not to me), and upgrading to a higher quality and more powerful amplifier will yield no benefit if the current one provides enough power without clipping. Differences in perceived audio quality between the two are due to the placebo effect, and audio quality cannot be reliably differentiated with ABX tests.

This is a very crude testing methodology and only reflects my personal experience with the two DAC/amps I used in my comparisons. I have very limited knowledge of audio science and can only experiment with my hearing. It may also be that I am hearing impaired and I am simply unable to hear differences that should be there, haha.
 
My current set-up: iPhone 15 Pro Max => USB C Data Cable => Fiio BTR15 => Hart 4.4mm Balance Cable => Hifiman Ananda Nano

I’ve recently upgraded my DAC/amp combo from a Fiio BTR15 to a Fiio K7. The main reason for this upgrade was the higher power output. The K7 uses two THX AAA 788+ Amps, outputting L+R≥2000mW+2000mW(32Ω /THD+N<1%). The BTR15 has a power output of L+R≥340mW+340mW (32Ω,THD+N<1%). They have different DACs, but I don’t believe DACs are of low enough quality to make a difference.

I upgraded because I heard planar magnetics will benefit from the increased current. I am not very knowledgeable about audio science, but I’ve read arguments from both sides about whether it matters. My line of thinking was that even if the Ananda Nanos do not benefit from the higher power, higher-quality amplifiers must have a better implementation, lower noise, or some other reason for an increase in audible performance. Why else would anyone upgrade their amp or spend thousands if there was no audible benefit to higher power and better quality amps once the power requirement was met?

Additional specs for the K7 and BTR15:
K7: DAC: AK4493S*2 , USB: XMOS XUF208 , Volume IC:NJU72315 * 2
BTR15: DAC: ES9219MQ * 2 ,USB: XMOS XU316, Bluetooth decoding: QCC5125

After receiving my K7, I promptly hooked it up to my iPhone and was very pleased with the results. It sounded like it had more bass, fullness, and clarity. As a scientific person, I wanted to validate that it wasn’t a placebo effect. When I compared the BTR15 with the K7, I used the same iPhone playing the same song segment, cable, and headphones, and tried my best to ensure that levels matched.

Since I did not have an objective tool to measure level outputs, I tried setting the K7 slightly lower than the BTR15. To my surprise, after waiting in silence to reset my hearing perception, the BTR15, with its ever so slightly louder volume, sounded more bassy, full, and clear. I repeated this experiment many times, trying my best to match the levels while ensuring I knew which one had the slightly higher level. I also repeated this with varying volumes. The DAC/amp outputting the slightly louder volume sounded better in all instances.

After doing these tests for a few hours, I realized they both sounded identical. I even took small breaks in between to recover from hearing fatigue. Perhaps the difference lies not in the bass, highs, or fullness but in resolution. My theory was that the K7 could be more ‘revealing’ or ‘resolving’ than the BTR15, possibly due to better implementation of chips, less noisy amplification, etc. I could only think of testing this through lossy/lossless ABX tests. I am normally only able to pass the 96 kbps MP3 vs lossless test on this website: https://abx.digitalfeed.net/list.html, and cannot reliably pass the 256 kbps Apple AAC test. Perhaps with the new K7, I will be able to better hear the audible differences between high-quality lossy and lossless.

When performing the ABX tests, I used my iPhone 15 Pro Max => USB C Cable => K7/BTR15 => 4.4mm Balanced Cable => Ananda Nano. I used the iPhone because iOS does not resample audio before sending it to the external DAC. With Windows or MacOS, Chrome does not have an ‘exclusive mode’, and therefore, I felt that it affected the quality and reliability of the ABX test. I performed multiple ABX tests at different volumes for the next few hours. I concluded that the K7 did not, in fact, resolve detail more accurately than the BTR15. In fact, after listening and comparing both the K7 and BTR15 for an extended duration, I further felt that there was no audible difference in quality between the two.

Testing Conclusion
The Fiio BTR15 should be in a totally different class than the K7, with the K7 supposedly offering a much better listening experience than the BTR15; however, they sounded identical to me. If planar magnetic headphones benefit from higher current, it is not audible (at least not to me), and upgrading to a higher quality and more powerful amplifier will yield no benefit if the current one provides enough power without clipping. Differences in perceived audio quality between the two are due to the placebo effect, and audio quality cannot be reliably differentiated with ABX tests.

This is a very crude testing methodology and only reflects my personal experience with the two DAC/amps I used in my comparisons. I have very limited knowledge of audio science and can only experiment with my hearing. It may also be that I am hearing impaired and I am simply unable to hear differences that should be there, haha.

As you discovered, when listening to the same music from different sources, we tend to think the one that is slightly louder sounds "better". That is why volume matching is important when doing a comparison.
 
I have very limited knowledge of audio science and can only experiment with my hearing.

Congratulations.

You've done more to educate yourself in those few hours you spent doing those comparisons than you could have done by reading for weeks.

At the end of the day, you don't really need a lot of knowledge about how it all works (though that will help going forward to select gear based on competence vs the best story), you just need to be honest with yourself.

Focus on headphones or your speakers/room when you want to make things sound better. Get new gear if you need capabilities or power, not for 'better' sound.

Does this help you understand why so many members here are so obnoxiously single minded in encouraging folks to do some controlled listening tests before deciding on 'upgrading' to that new $10k DAC, or fancy cables, or whatever else if it is based on improved sound quality?

I don't think I could tell my Adcom amp from my Bryston from my Krell from my Devialet, assuming none were pushed into clipping.

Great post!
 
I just did a bunch of volume matched comparisons of amplifiers and they're all sounding the same these days, not just DACs anymore. An SMSL HO150x I got for $100 used and volume matched to a Topping A70Pro and I couldn't tell which I was listening to using the same SMSL D-6s DAC. I focus more on a low noise floor and being able to equalize with a preamp reduction and have enough power to stay out of high gain for best quality that way.
I remember when a laptop the size of a briefcase was $5500, and that's in 1988 money. Now you can get a laptop for $125 that would blow it away with performance. Audio has come so far, and prices plummeted for distortion free performance. I think we can save a ton of money knowing when to quit the upgrade game.
 
@TylerT

Thanks for posting this. Such realizations can be humbling, humiliating even, but sobering,and .. liberating. Yes! High Audio performance is now at the commodity level. We should have seen it coming with the advances in electronics and computing, but we were lead to believe that "Mo'h expensive = Mo'h Better" :D. for so long

It's a good time to be an audiophile! ... especially if you follow ASR and Science ;).


Peace.
 
Words sometimes get a life of their own in the web. "Benefit from more current". Well, yes, planars tend to be partial to that side. That is true. But when requirements are met there is nowhere for the extra power juice to flow and it's all the same, simple as that. Amplifiers are not meant to be amazing and mythical. They just have one job and that job does not include "more revealing" etc. That's speaker/headphones' job.
 
Thank you, everyone, for the positive responses!

I agree it’s a great time to be an audiophile. Quite a few years back, when I was a broke student, I had a Fiio E10k and a Sennheiser HD 598se. I remember a friend owning a Hifiman Edition X with a fancy Fiio DAP. After trying that, I was utterly blown away by how great I thought it sounded. That laid the foundation for my love of planar magnetics made by Hifiman. Back then, the Edition X cost well over a thousand dollars; fast forward to now, and the upgraded Ananda Nano only costs $700 CAD.

It's good to know that I don’t need to upgrade to absurdly expensive DACs and amplifiers to ‘unlock’ headphone capabilities.
 
Thank you, everyone, for the positive responses!

I agree it’s a great time to be an audiophile. Quite a few years back, when I was a broke student, I had a Fiio E10k and a Sennheiser HD 598se. I remember a friend owning a Hifiman Edition X with a fancy Fiio DAP. After trying that, I was utterly blown away by how great I thought it sounded. That laid the foundation for my love of planar magnetics made by Hifiman. Back then, the Edition X cost well over a thousand dollars; fast forward to now, and the upgraded Ananda Nano only costs $700 CAD.

It's good to know that I don’t need to upgrade to absurdly expensive DACs and amplifiers to ‘unlock’ headphone capabilities.
Next step, do try to EQ your headphones. A definite Game Changer.
Relatively easy if you use your PC as your source.
Download PEACE EQ

Peace
 
It seems to me that with devices like DACs and headphone amps we've hit a point where a good one in the $50 - $100 range will be difficult to distinguish from one costing 10X as much. The more expensive ones are probably better, but human hearing is not good enough to perceive the difference. This is something I'm glad to have lived to experience.
 
Really nice work putting in the time and taking it seriously, but more importantly being honest with yourself about what you heard and not taking your first impression as fact. There are people out there who will quite aggressively argue that point.

IME if you want to hear a difference between two HP amps, the easiest way to do it is play tones below 50hz (closer to 20 tends to stress them even more), and loud. Not saying you will hear one, but if there's one to be heard, that's the quickest way to get an amp to run out of juice. :)
 
Other than maybe tube amps, the only components that affect sound quality are headphones and speakers. Assuming everything has enough power to operate of course.
 
Additional specs for the K7 and BTR15:
K7: DAC: AK4493S*2 , USB: XMOS XUF208 , Volume IC:NJU72315 * 2
BTR15: DAC: ES9219MQ * 2 ,USB: XMOS XU316, Bluetooth decoding: QCC5125

None of these components are the actual amplifiers driving the headphones, but it matters not since achieving low single-digit watts of output power with THD+N magnitudes lower than the inherent THD of the headphone is trivial in electrical engineering these days.
 
Not really. Often the only thing better about the expensive ones are the lies, ....snake oil marketing.
What I was saying was that the more expensive ones may measure better but the improvement is beyond the limits of human hearing so it doesn't matter to the user.
 
Of course, if the better amp really has more power, then it should have some extra headroom to handle the bass boost that is often needed in these planar headphones to get them closer to neutral.
 
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