[Erick Muller]

Temperature update....

Okay AFTER 20 hours, 100ma mode, high gain, 4 pin XLR balanced output 1.5m (4.9f) cable, and 73f (23c) room temps.....

It is holding at 53c.

Test Conclusion:

• This fan is MORE than enough to control the temperatures of this unit.
• With the inline on/off switch, I can now keep the temperatures AT ANY temperature I want.
  • Want higher temps, turn the fans off with the in-line switch which for me is right next to the unit.
  • Want lower temps, turn the fans on and then off when you reach desired temps.

You seem to have the perfect to control the temps on your amp, this seems like and excellent solution.

 

[sendler2112]

Has anyone seen any reports of refurbished S17 amps available for purchase?

 

[Erick Muller]

. @MiguelP I am perfectly enjoying the heck out of my XS listening to music like never before...


Now I don't need to watch them anymore.... By the way for the "hot amp" peeps, 55c is 131f. Are you all saying the amplifier is not hot enough to sound great at 131f.. because it sounds fabulous to me... 60c would be 140f. So the missing 9 degrees f is not causing me any issues.

So everyone enjoy

Look tbh, I don't notice much difference sound wise in whatever temp you happen to turn of the 100ma, but some people report that the optimal temp for best sound performance and quality is around 65 degrees, so play around if you notice a difference and then decide what's best for you.

 

[Erick Muller]

Guys, which gain setting do you use? I've always followed the rule that if the headphones are loud enough, use low gain to reduce noise. Well, my most demanding headphones, the Edition XS, are certainly loud enough at 30-35 volume in low gain for most situations. However, the EF400 worked differently; high gain increased not only the volume, but also the impact and dynamics. I used it as the default setting. What about the S17?

Ok. For now I'm using the XLR-RCA connection until XLR-XLR arrives.

It's SO GOOD, so powerful! The impact and dynamics on this brick! The soundstage! The amplifier on the ST-AMP is no slouch, nor is on the EF400, but the way my neutral/brigth(ish) headphones sound on the EF400 > S17 is great. I drafted a short comparison between the ST-AMP and the S17, but then realized I almost repeated what @Ichos already said, same impressions. So let me just quote it:

The difference in impact is quite significant. Even comparing to the EF400 solo, which already has a powerful sound presentation. Lots of body, no fatigue. I really like it.

Interestingly, I preferred the OS mode with the ST-AMP as it adds more heft and warmth, but with the Aune I much prefer NOS, which is a true R2R mode. This seems to confirms the notion that this amp pairs very nicely with R2R DACs like the EF400.

Comparing the S17 to the EF400 solo:
1. Even more impact.
2. Shoutiness gone.
3. Sibilancy gone.
4. Mids hollowness gone.
5. Just as big if not bigger soundstage, but better extended, layered and more 3d.

ST-AMP is also able to take care of points 1-4, but to a lesser extent and with a much less weight.

About temperatures: It stabilized at 59°C in 100mA mode with my 1.4m Openheart 16-core balanced cable, low gain, volume 32. I'm quite happy with that. However, the unit is elevated sitting on some LEGO blocks for testing At first, when I placed it directly on my desk and stacked the EF400 on top, it reached 65°C in 3 hours and continued rising. No doubt it would keep going and throttle at 70°C. It was already too hot to touch, especially on the bottom. So I removed the EF400 and placed the amp on LEGO. The temperature dropped by 5°C in 30 minutes just by doing this.

I also added a USB fan underneath the unit, so I can activate it with the wire control if the temperature exceeds 60°C, which I aim to prevent. I tested it, and it cools it down quickly, then it takes another 1-2 hours for the temp to go back up. Like @SpiritualAbies2600, I'm going to turn it on/off when needed.

Overall, it's a great purchase. I bought lots of stuff in the last few months but don't remember being so happy.

I think most people at least have elevated their amp in order to control the temps on the amp as a bare minimum, I also have it elevated on a perforated metal rack and I have a pair of 120mm fans underneath them.

Given that several people have already reported that this amp pairs great with R2R DACS, gives me more reason to buy the Holo Audio Cyan 2 and feed some upsample PCM sound files and pretty much have my more than likely end-game setup.

 

[Erick Muller]

I mean, in my experience if you do a few certain things for the wife she tends to not bish about reasonable purchases...

>Reasonable purchase
>Proceeds to buy a DCS Lina DAC and master clock stack to feed a mass kobo amp.

 

[SmartCheetah]

Well you're a married man now and you know you'll have to compromise with her on several things, and your priority should always be to keep your wife and the rest of your family happy

Amen, brother. This made me hug my wife and daughters.

so long as you are spending what's completely disposable income that's not needed for anything else more important and you're being responsible with your family finances

We've been blessed in that regard, I might buy a lot and often, but it's still a fraction of our resources. My wife is aware of that too, she turns a blind eye

The volume seem to be an issue with the first batch of S17, in which every for steps it would increase the volume, sometimes substantially, now it seems to have been solved with newer units.

Interesting. I tested it with my sensitive MSR7b with a balanced cable and realized that it changes every other step on mine, I didn't notice it with my planars before. I thought my unit was faulty too, but it looks like it's the new normal on "fixed" units?

Cheers my friend and congratz on your new purchase!!!!

Remember that this is a fully discrete, class-A amp and it has to run for some time before the electronics inside the amp settle down and you get the full sound potential of this amp, it might take a few weeks.

Thanks! I bought it slightly used, 2 month old, so it should be already burned in, if that's a thing.

Also, I just emailed Aune Europe asking them 2 questions about the optimal operating temperature. There seem to be lots of conflicting information floatig around. In short:
1. Should the temp be the lowest possible for reliability and reduced wear of internal components?
2. If not - what's the recommended range for the best (sonic) performance?

 

[davveswe]

Hi, firmwares can only optimize volume and cannot modify current.



As the S17 Pro is a pure class A headphone amplifier, if a cable is too long and lacks sufficient internal insulation, it may increase the overall load and potentially generate more heat. (High ambient temperatures and low impedance headphones can cause temperature increases too.)

Does the s17 pro have DC offset protection?

 

[mealen]

Has anyone compared the s17 to the Cayin iHA-6 amp? It seems to be powerful too, but there is practically no word about heating there

 

[Rolandmangrove]

We're drifting a bit off topic here but having watched and read all the reviews I could find with many of them comparing the HEKS with the HEKSE (which was half as much again at the time) and only finding small differences, I think the HEKS is the better value. A couple of them even said they'd choose the Stealth over the SE.

I see you have the HE1000 stealth. Next week I'll get the HEKSE to try out. How do you like the combination of the Aune with the Hifiman?

 

[Dimitry188]

HE1000 stealth. Next week I'll get the HEKSE to try out. How do you like the combination of the Aune with the Hifiman?

I use Aune together with HFM 1000se.
It sounds great. Transmits the smallest details and at the same time (compared to other amplifiers) makes the midrange frequencies more dense and saturated.

 

[SmartCheetah]

Has anyone compared the s17 to the Cayin iHA-6 amp? It seems to be powerful too, but there is practically no word about heating there

iHA-6 should have more neutral sound signature, but still warmer than something like the Topping A90. In theory at least.

Cables arrived, I swapped my XLR-RCA set for XLR-XLR to connect the EF400. I didn't A/B them, but I don't perceive any difference in SQ since yesterday's setup. But the peace of mind is the biggest upgrade

 

[SmartCheetah]

Open question to owners: In your own words and based on your experiences, can you describe the difference in sound quality between the 100mA and 50mA modes?

 

[Rolandmangrove]

I use Aune together with HFM 1000se.
It sounds great. Transmits the smallest details and at the same time (compared to other amplifiers) makes the midrange frequencies more dense and saturated.

Okay, thank you. I use a balanced Forza 4 pin xlr HPC noir cable and am very curious about how it sounds. Is it also your experience that the Hifiman needs 100 hours of break-in time to really come into its own?

 

[kjp473]

Open question to owners: In your own words and based on your experiences, can you describe the difference in sound quality between the 100mA and 50mA modes?

I was wondering what other though myself, but decided I would test it more first before asking as I haven't experimented much with mine yet.

The difference may be more or less noticeable depending on headphones used, but so far with a brief a/b on my Abyss Diana MR there is a subtle perceived shift in the sound. I haven't exactly honed in on what exactly it is, but my initial impression is that 50mA gives a slightly 'cleaner' sound.

99.99% of my listening so far has been on 100mA but I have a feeling that the 50mA may actually be to my preference with the Diana MR. More testing needed when I find the time.

 

[SussyTofu420]

Hopefully Aune releases a successor at some point without all the "quirks" of the S17 pro. Very intrigued by the sound descriptions, but having to even think about the operating temperature seems like a massive flaw in product design. I can just turn my Burson on and never have to worry if running it during the summer will change the sound.