Aune S17 pro

[Vap221]

Yeah, would be great to hear from Aune.

I find the correlation between distortions and heating very interesting. Since my unit doesn't have any temperature issues in 100mA, tested with multiple headphones and cables, I'm assuming the interference isn't that bad.

@Vap221 so 4.4mm performed better?

Distortions or not, it does sound unique though, and not only due to its energetic, impactful timbre, but also its technical capabilities. When amps like the EF400 start to sound congested and messy, the S17 is still resolving.

my device doesn't overheat either. but I don't use Highgain and I used the 100mA current only to check the heating and compare the "nature of the sound". But when the amplifier is excited, the temperature starts to rise faster. In any case, self-excitation and network background are not allowed in devices of any price.

In addition, I can't think of other reasons for the dependence of heating on the cable used.

 

[Erick Muller]

Oscillograms of self-excitation of the amplifier. in some cases, modulation is present.

@AuneAudio

 

[Erick Muller]

if the level of these interferences is small, 50-500mV, this leads to a slight increase in heating and the occurrence of harmonics, see the image. If the noise level is high, as on oscillograms, this leads to rapid heating, noise in the path (faintly audible on tight headphones).

I want to note that on a pseudo-noise signal or a multitone, the dynamic range will not exceed 70-80db. And what kind of audiophilia is there?

This is way above my pay grade, I would leave to the experts to discuss this findings.

 

[Erick Muller]

my device doesn't overheat either. but I don't use Highgain and I used the 100mA current only to check the heating and compare the "nature of the sound". But when the amplifier is excited, the temperature starts to rise faster. In any case, self-excitation and network background are not allowed in devices of any price.

In addition, I can't think of other reasons for the dependence of heating on the cable used.

What do you mean by network background, like are we talking about radio waves of wi-fi?

 

[Vap221]

What do you mean by network background, like are we talking about radio waves of wi-fi?

network background. interference from the supply network.
as well as its harmonics multiples of 50(60) Hertz and intermodulation interference.

(I translated it with difficulty)

 

[Erick Muller]

network background. interference from the supply network.
as well as its harmonics multiples of 50(60) Hertz and intermodulation interference.

(I translated it with difficulty)

Does this means the electrical grid itself from what I'm able to understand?

 

[AntonNZ]

@Vap221
Thanks for your insights. Unfortunately, I don't understand it entirely, but my main takes are:
1. XLR and 4.4 are not paralleled (this is very concerning to me)
2. There is mains interference through the power supply that can affect the output sound characteristics
3. The unit can transmit some noise on short waves.
I want to reconfirm some points. Can you please check the video here (you can do subtitles with auto translate) with s17 pro measurements?

Are measurements in the video similar or are they different? the engineer in the video seemed to be completely happy with the performance. If they are similar can it be that your specific unit is faulty?

 

[Vap221]

@Vap221
Thanks for your insights. Unfortunately, I don't understand it entirely, but my main takes are:
1. XLR and 4.4 are not paralleled (this is very concerning to me)
2. There is mains interference through the power supply that can affect the output sound characteristics
3. The unit can transmit some noise on short waves.
I want to reconfirm some points. Can you please check the video here (you can do subtitles with auto translate) with s17 pro measurements?

Are measurements in the video similar or are they different? the engineer in the video seemed to be completely happy with the performance. If they are similar can it be that your specific unit is faulty?

It measures with low gain and a current of 50mA. from an unbalanced exit. everything is OK with me in low gain too. I did not take measurements from the unbalanced output. (in general, I almost didn't use it) but on the sensitive headphones, you can hear the background of the supply voltage there.

 

[Vap221]

I also conducted a power, voltage and clipping test, if anyone is interested, please write.

 

[Erick Muller]

I also conducted a power, voltage and clipping test, if anyone is interested, please write.

I think everybody here is intrigue by your findings my friend, even though they might be going over my head.

 

[AuneAudio]

@AuneAudio

Thanks everyone for your continued attention and your feedback

1. Regarding measurements:

Here are the measurements on our website:

The S17 Pro has done a fairly good job keeping the low noise floor in the state of class-A. And each unit undergoes hours of aging and QC before leaving the factory.

Many of you should have a lot of experience with amplifiers and other audio products. Just by plugging in headphones, you are able to judge the device's noise level.

If any anomalies occur, these might be the possible causes:

1) If you are doing tests on your own, please pay attention to the grounding loop of the testing instrument, as this can lead to abnormal test results.

2) 50Hz interference from mains power.

3) Abnormalities in the S17 Pro.


2. High-frequency self-excitation:

The development process of the S17 Pro includes a stage for self-excitation inspection. We conducted tests using standard cables, and no self-excitation was detected.

The S17 Pro is designed with several special features:

1) It is a class-A headphone amp with relatively large output current. It actually outputs double the current with two pairs of transistors.

2) The tuning is transparent and clear type within class-A amplifiers, with excellent high frequencies. We believe the S17 Pro users can feel it. It has a relatively wide frequency response bandwidth. This setting has been reviewed by sound engineers and has also passed hardware stability tests.


If self-excitation occurs:

1) Please check if the headphone cable has relatively large parasitic capacitance and inductance, as this may cause anomalies.

2) The S17 Pro operates in a multi-transistor parallel and class-A high current working state. If one of the transistors has an abnormal amplification factor, self-excitation may occur, but the probability is very low.

---

If you don't experience noise or abnormal heating during actual use, please don't worry. The S17 Pro is a class-A headphone amp with professional and aesthetic tuning. It is not just an electronic device; it is a meticulously crafted product by tuners and engineers with love and passion

If your device experiences any anomalies, please refer to the information above and contact us.

 

[ngohw]

Always good to see such meticulous detail go into measurements but I would be lying if I said I knew what any of this meant

 

[Majuto]

Always good to see such meticulous detail go into measurements but I would be lying if I said I knew what any of this meant

Inductance and capacitance may be shown in cables technical data, but parasitic capacitance and inductance (whatever they mean) propably not. Aune answered that relatively high values of these can cause self-excitation=excess heating and interference??=possible problems. This is good to know, but reference values would be needed. And if these parisitic parameter values are not exposed in the cable info, it gets difficult.
I know that I have cables that cause self-excitation differently, but I've got non whatever idea of their parametric values. A database of suitable cables would be nice, if one dropped down from heaven.

 

[Erick Muller]

Inductance and capacitance may be shown in cables technical data, but parasitic capacitance and inductance (whatever they mean) propably not. Aune answered that relatively high values of these can cause self-excitation=excess heating and interference??=possible problems. This is good to know, but reference values would be needed. And if these parisitic parameter values are not exposed in the cable info, it gets difficult.
I know that I have cables that cause self-excitation differently, but I've got non whatever idea of their parametric values. A database of suitable cables would be nice, if one dropped down from heaven.

Unfortunately I think it would be an impossible task given how many different cables are on the market, the only way you're going to find about it is to connect to your HP and then the S17 and see if the temps start rising really fast on the amp, then you have a "bad" cable, and this assumes you have a "good" cable to compare it too already paired with the same headphone that doesn't have those issues in combination with this amp.

The other way would be to have all that measuring equipment and 99.99% of people, even in this forum, don't have it.

 

[Simon Patten]

Arya Stealth, HE1000SE. Change is there, but subtle. I doubt I'd noticed it on the fly. But it's definitely there

I found the main difference between 50ma and 100ma is that in 100ma mode the bass has a bit more weight and the sound is slightly warmer. 50ma feels a little more detailed and clean. That said, I can barely hear a differerence, it's more about the feel of the sound and how it affects me. I tend to stick with high gain and 100ma as it's more fun.