[Marlowe]

The problem was wanting at all costs to maintain that typical design of their S series (which they have been using for many years now) for a device that would have at least needed ventilation grills on the top. Unusual is to build a pure class A amplifier inside a completely closed enclosure. Class A amplifiers operating at maximum voltage need at least multiple ventilation grills or adequate dissipation systems with noticeable external fins that release heat. I'm in Italy and it's cold now and maybe it could work but as soon as our very hot Italian summer arrives it will be possible to use it in 100mha mode for no more than 5 minutes maximum.

The chassis is not completely enclosed--there is a narrow bank of vent perforations on the rear along the top left edge above the input/outputs and a smaller bank on the right above the power switch; Aune's website notes them as part of the cooling system. They are unobtrusive and easy to miss and (with the caveat that I am far from an engineer) appear inadequate to vent the amount of heat that the S17 produces. (In contrast, the Class A Schiit Mjolnir 3 has much more extensive venting on the top and sides and almost the entire external surface of the Class A Burson Soloist is a finned heat sink. Frankly, this may partially explain why the S17 can compete with these more expensive units on sound quality at a significantly lower price.) Ditto for the very short feet, which are a stock component of the S chassis and should have been replaced for this application. (After unboxing the S17, even before I plugged it in, the first thing I did was add extra tall aftermarket feet that raised it almost an inch above my Denafrips Ares 12th-1. BTW, I've been criticized for this stacking, which is necessitated by my space limitations, but the Denafrips only gets slightly warm and remains significantly cooler than the S17.)

 

[Guy Fawkes]

The chassis is not completely enclosed--there is a narrow bank of vent perforations on the rear along the top left edge above the input/outputs and a smaller bank on the right above the power switch; Aune's website notes them as part of the cooling system. They are unobtrusive and easy to miss and (with the caveat that I am far from an engineer) appear inadequate to vent the amount of heat that the S17 produces. (In contrast, the Class A Schiit Mjolnir 3 has much more extensive venting on the top and sides and almost the entire external surface of the Class A Burson Soloist is a finned heat sink. Frankly, this may partially explain why the S17 can compete with these more expensive units on sound quality at a significantly lower price.) Ditto for the very short feet, which are a stock component of the S chassis and should have been replaced for this application. (After unboxing the S17, even before I plugged it in, the first thing I did was add extra tall aftermarket feet that raised it almost an inch above my Denafrips Ares 12th-1. BTW, I've been criticized for this stacking, which is necessitated by my space limitations, but the Denafrips only gets slightly warm and remains significantly cooler than the S17.)

I know that there are holes on the back as on all Aune S series devices, however I was hoping that no one would point it out to me as these holes are not sufficient and their position is not adequate for correct ventilation of the heat, the grill ventilation on a device that generates such heat should be placed on top and not behind, MJ3 is certainly better designed for this purpose. I am quite convinced that Aune did not want to do it to maintain the cleanliness of the design as it has been linked to it for many years now.

 

[Metalboyy]

I have had the S17 Pro now for awhile. It takes about 1.5-2 hours for it to reach 69 degress with a Hifiman Ananda nano.

 

[Guy Fawkes]

I have had the S17 Pro now for awhile. It takes about 1.5-2 hours for it to reach 69 degress with a Hifiman Ananda nano.

Where are you? and what is your ambient temperature?

 

[Metalboyy]

Where are you? and what is your ambient temperature?

Sweden. Maybe 18-20

 

[MiguelP]

One thing every person could try is to test their unit with different room temperatures (using heating or air conditioning). I've done that and found out that a 10 degree variation in room temperature translates to the same variation in the maximum temperature of the amp).

 

[slsmaster]

Was the s17 standing on a stone plate? What was the relative humidity at 18C?

No, my table just has such a pattern but is made out of wood.
I really have no clue why my unit had no temperature issues.

I can only suspect that maybe there are some tolerances how the heatsink is mounted.

 

[Zaemon]

Im glad i dont have to follow this any longer because i returned it. Maybe the design will get better but for now im done with Aune. They have to redesign ventilation and heat transfer. The remote is a struggle too. Vol +- interchanges sometimes and one has to aim like a sniper. Just to good to be true. Like a relationship with a beautiful woman who gets on my nerves so much that it isnt worth the trouble

 

[Carmignola]

Sorry for that. Only Nonsense. Have to read more.

 

[MiguelP]

Best fans to use to cool down S17 Pro? Artic F9 Silent? Noctua PWM (which size?)? Other? I have two normal fans that do the trick but I can listen to them in silent parts of the music, even with headphones on (open backs, of course).

 

[Carmignola]

Best fans to use to cool down S17 Pro? Artic F9 Silent? Noctua PWM (which size?)? Other? I have two normal fans that do the trick but I can listen to them in silent parts of the music, even with headphones on (open backs, of course).

I have two Artic F9 silent at 12V. Most time, the controller only drives them with 6V to keep the s17 at 55°C (100ma). Even at 12V full Power, you cannot hear them in more than one meter distance (without HPs on). But you feel the airflow

 

[Riversalt]

The problem was wanting at all costs to maintain that typical design of their S series (which they have been using for many years now) for a device that would have at least needed ventilation grills on the top. Unusual is to build a pure class A amplifier inside a completely closed enclosure. Class A amplifiers operating at maximum voltage need at least multiple ventilation grills or adequate dissipation systems with noticeable external fins that release heat. I'm in Italy and it's cold now and maybe it could work but as soon as our very hot Italian summer arrives it will be possible to use it in 100mha mode for no more than 5 minutes maximum.

Perfect!!
I agree with everything you said, it's a wonder we hobbyists/customers have to say something so obvious to the manufacturer, who remembers the first launch of Fiio the closed K9 pro, without ventilation openings that only came later in a chassis update?
Aune needs to wake up to this ventilation problem, they at the factory also have CNC tools. It wouldn't be that difficult to add openings to the chassis, you just need to want it.

 

[Marlowe]

While my S17 does not stay quite as cool as some, it generally is at 63-64° even after 3-4 hours of operation (I've seen 65° a couple of times, but never higher). However, I am concerned about the summer, since it appears that even a few degrees difference in ambient temperature can have a significant impact on the S17's internal temperature. However, I assume the problem can be fixed by a relatively inexpensive fan (making it merely annoying). I note that some people have placed or mounted fans underneath the unit, but that's probably not practical for me since my S17 is stacked about .9 inches above my DAC, leaving little to no room for a fan. However, if it's not a dumb question (I'm not a scientifically or technically skilled person) is there any reason not to place a fan on the top of the unit?

 

[Riversalt]

While my S17 does not stay quite as cool as some, it generally is at 63-64° even after 3-4 hours of operation (I've seen 65° a couple of times, but never higher). However, I am concerned about the summer, since it appears that even a few degrees difference in ambient temperature can have a significant impact on the S17's internal temperature. However, I assume the problem can be fixed by a relatively inexpensive fan (making it merely annoying). I note that some people have placed or mounted fans underneath the unit, but that's probably not practical for me since my S17 is stacked about .9 inches above my DAC, leaving little to no room for a fan. However, if it's not a dumb question (I'm not a scientifically or technically skilled person) is there any reason not to place a fan on the top of the unit?

In the rear part where there are the holes, it could be placed nearby, pulling the hot air from the inside, it would be very efficient, since it can be sealed and there is the only air outlet and the hot internal air must rise in a straight line and only then go little by little. for these small holes that alone shouldn't be of any use, if only they were bigger holes.

 

[Riversalt]

Fiio K7 mod griil.