Aune S17 pro

[sendler2112]

I have found that using the Susvara EQ presets with my HiFiMan HE2000 V2 (non-stealth) greatly improves the sound. Here are my Math Audio and PEACE presets in case anyone else wants to try:

I tried to get a Math Audio EQ thread going here but never got a reply.
https://www.head-fi.org/threads/min...-math-audio-eq-playback.971363/#post-17918821

 

[MiguelP]

I agree, this confirms my impressions. The difference is quite subtle, though. Switching between OS and NOS modes in the EF400 is noticeably more impactful. Regardless, for neutral/bright headphones, like most HiFiMan planars, 100mA should be the default setting. For some thicker-sounding, warmer dynamic headphones, 50mA can be a good alternative.


This is an interesting perspective. I heard this before, that this amp performs better when it's warmer. Mine won't exceed 61 degrees, so can't test it properly


Then the cables theory is not true. I'll test it anyway and report back.


What surprises me is the inconsistency, especially the temps. My unit has zero issues, it runs cool at 100mA without any active cooling, the volume works perfectly, and no any other problems so far. In contrast, for some user it's much warmer, even at 50mA.

I have a theory that the amps that do not get hot are the ones that are defective and maybe they are effectively unable to run in 100ma. That would explain a lot of things

 

[AntonNZ]

I performed this task highlighted above two days ago and have documented my process here: https://imgur.com/gallery/pPL1fnQ

I have used the amp for over 24hrs and my unit can now stay at a constant 67 degrees without active cooling, but it still needs to be raised on tall feet.

voiding warranty - a bold move. Awesome work. I have couple of questions:
- why did you decide to move the sensor?
- do you think it will be possible to attach the thermal pad between the lower heat sink plate and the amp case so the heat transfer to the case will be more efficient?

 

[SmartCheetah]

I have a theory that the amps that do not get hot are the ones that are defective and maybe they are effectively unable to run in 100ma. That would explain a lot of things

And my theory is that it's the newer batches that aren't as warm. Perhaps they did more than addressing the volume knob/potentiometer issue. Maybe heatsinks weren't tightened enough, for example?
If the temperatures remained the same in both modes, I'd consider your theory For me, it's around 60°C in 100mA and around 50°C in 50mA. Also they sound different. It's not that every class A amplifier overheats you know. They are warm by design, sure.

However when I had it not elevated and stacked the EF400 on top, it reached 65°C in 2-3 hours and continued to rise. It was only a matter of time before it reached 69°C for sure.

 

[MiguelP]

And my theory is that it's the newer batches that aren't as warm. Perhaps they did more than addressing the volume knob/potentiometer issue. Maybe heatsinks weren't tightened enough, for example?
If the temperatures remained the same in both modes, I'd consider your theory For me, it's around 60°C in 100mA and around 50°C in 50mA. Also they sound different. It's not that every class A amplifier overheats you know. They are warm by design, sure.

However when I had it not elevated and stacked the EF400 on top, it reached 65°C in 2-3 hours and continued to rise. It was only a matter of time before it reached 69°C for sure.

Some problem that causes that each channel only has 50mA/100mA instead of 100mA/200mA? It would run in a higher temperature in the higher bias setting but it would have half the current than a non defective unit and hence a lower temperature?

 

[Erick Muller]

Imho and in my experience, it's not the external temp or other to determine the overheating...it's the headphone cable...

Yep, the HP you're using and the cable are the things that most affect this unit, of course if you put this amp in a close in place with no ventilation, temperatures are going to rise, but I think that at most, you need to put the amp on some stands, elevated at least an inch, inch and a half in a well ventilated area and you're set, the USB fan it's for us the crazies that spend to much time on this forum.

 

[Erick Muller]

I am going to see if I can exchange my unit as I think I got one that is overheating.

So I turned off the "mini fan" to see what happens... So in 100ma it hit 69 shortly then turned itself into 50ma. Just like 1st day it kept climbing, when it hit 73c, I turned it off. From everything I had read/experimented with, the unit should NOT go over 70c once it kicks itself back to 50ma.

At this time, I have tried 3 different cables (XLR, Pentacon, and etc). So I am considering mine one of the "bad" ones. I can definitely cool it way down with the laptop cooling pad, but I am worried about future warranty issues as mine wants to constantly climb over 70c without ACTIVE cooling even when it goes back down into 50ma mode.

It shouldn't exhibit that behavior, at most you should only see very occasional reach 70 degrees tops, there's definitively something wrong with your unit, you should talk to @AuneAudio about your problem.

 

[Erick Muller]

@SpiritualAbies2600 I'm sorry, that must be frustrating. It's weird it keeps rising in 50mA mode.

For some comparison, also to @anonbert: 100mA, no active cooling. Low gain, volume range 12-38. The amp was on for the whole day, playing music. It stabilized after 3 hours at 61 degrees Celsius while I was using my planars and the balanced 16 core cable, and it did not go higher than that for the next 6 hours while I was listening to music and working. After that, I switched to my KZ ZAX IEMs with the stock 3.5mm cable, and the temperature went down to 60 degrees Celsius soon after. Then, I read your post, @SpiritualAbies2600, plugged in the ATH-MSR7b with the stock balanced cable, and also switched to 50mA. In 15 minutes, the temperature went down by 5 degrees to 55c.

I'm quite happy with the temperatures, but they differ significantly from yours, which is surprising. I have used a number of different headphones/IEMs and cables, but the temperatures seem to be rather consistent between them in 100mA.

I ran my S17 yesterday all day on high gain 100ma mode into my active speakers and it reach 64 degrees and then it came down and stabilized to 63 degrees, no problem and it sounded amazing. I did notice a sound difference going from low gain to high gain in 100ma into my speakers, the bass seem to have more weight to it and the mids become super smooth.

 

[Erick Muller]

I agree. The biggest mistake Aune has made is to include the screen. It would be perfect if they opted for switches.

Miguel

Specially given the OCD tendencies inside the audiophile community, the screen showing so much information about the internal workings of the amp is an excellent feature, but might have been a mistake, but it's understandable given that people where going to ask questions when their amp switched back to 50ma after some use and that might have been the reason why Aune implemented it in order to avoid this other issue that might have been worse if people couldn't tell why their amp suddenly stopped sounding like they wanted too and the only indication they got that change is a relay switching, at least in this way we can monitor the temps and if you want to maximize your use of the amp, you can do so.

 

[Erick Muller]

Do you know if the Schiit Mjolnir 3 steps down in sound quality if the internals reach over a certain temperature?

Nope it doesn't, but it does have better internal ventilation and a huge freaking heat-sink, that's what an extra $600 usd gets you.

 

[SmartCheetah]

Some problem that causes that each channel only has 50mA/100mA instead of 100mA/200mA? It would run in a higher temperature in the higher bias setting but it would have half the current than a non defective unit and hence a lower temperature?

That's too much mate But let's assume it's true - then this amp wouldn't be widely praised for the SQ, and everyone agrees it sounds terrific. The halved 50mA mode would deteriorate the sound noticeably, resulting in reduced impact, loss of clarity and resolution. The sound would be audibly flatter and compressed. Additionally, the difference between the modes would be much bigger. I comparedit directly to the FiiO K7, the Earmen ST-AMP, the EF400, the Gustard H20. Only the H20 and the EF400 (in some tracks) could keep up.

I ran my S17 yesterday all day on high gain 100ma mode into my active speakers and it reach 64 degrees and then it came down and stabilized to 63 degrees, no problem and it sounded amazing. I did notice a sound difference going from low gain to high gain in 100ma into my speakers, the bass seem to have more weight to it and the mids become super smooth.

Yeah, I personally didn't find any significant difference in sound quality between gain modes on headphones (though I didn't test it too much). However, on speakers, it makes sense to push more power with high gain. Also, the temperatures sound about right.

 

[Erick Muller]

And my theory is that it's the newer batches that aren't as warm. Perhaps they did more than addressing the volume knob/potentiometer issue. Maybe heatsinks weren't tightened enough, for example?
If the temperatures remained the same in both modes, I'd consider your theory For me, it's around 60°C in 100mA and around 50°C in 50mA. Also they sound different. It's not that every class A amplifier overheats you know. They are warm by design, sure.

However when I had it not elevated and stacked the EF400 on top, it reached 65°C in 2-3 hours and continued to rise. It was only a matter of time before it reached 69°C for sure.

I did notice that my amp gets noticeable hotter on the right side of the amp, right where the volume knob is compare to the left side, hasn't cause any issues, but I found that even when it's running at 65 degrees, I can touch the surface of all the amp, except that side, that's getting uncomfortably hot to the touch at least for me.

 

[Erick Muller]

Yeah, I personally didn't find any significant difference in sound quality between gain modes on headphones (though I didn't test it too much). However, on speakers, it makes sense to push more power with high gain. Also, the temperatures sound about right.

The S17 is an absolute beast as a pre-amp for sure, like everybody praises this amp for it's sound coming from headphones, but they should use it like Zeos did on a two channel system and that's why he called it "the fixer".

 

[SmartCheetah]

I did notice that my amp gets noticeable hotter on the right side of the amp

The power supply is on the right

I can touch the surface of all the amp, except that side, that's getting uncomfortably hot to the touch at least for me.

I only reached 65°C the day it arrived, before I learned it's a good idea to elevate it and not stack it with another large device like the EF400. Regardless, at that temperature, it was too hot for me to comfortably touch it, especially the bottom.

 

[Erick Muller]

The power supply is on the right


I only reached 65°C the day it arrived, before I learned it's a good idea to elevate it and not stack it with another large device like the EF400. Regardless, at that temperature, it was too hot for me to comfortably touch it, especially the bottom.

The bottom gets super hot too. and I thought the power supply was on the left side of the unit?, when I refer to the right side I'm talking when you're looking at the front of the unit, where the screen is, the side that the volume knob is on, that side gets super hot for me at least.