please tell me my fan is faulty

[curvebender]

So curvebender finally found me

I assume he was the guy who asked me to join the thread?

so here I am

Yes it was me, excellent detective work aribo!

Welcome to the forum, I'm glad you joined us.

Let's see if we can beat this fan/noise problem..

[panrixx]

.....the position of the fan right next to power supply makes sense to disperse the heat away from the CPU as power supply can get hotter, not the LCD, not the CPU not the motherboard, heat generated by power supply can accumulate and cause hiccups in performance of the CPU..

That is also my view on the need and positioning of the fan. I'm sure dispersion of heat from the PSU is the aim of this fan.

[aribo61]

hmm, I disagree...

First, the fan doesn't generate air flow through the PSU, but aside from it.
I don't think it can keep the PSU cool.

Second, my Kronos seems to heat up on the right, more where the motherboard is.

Third, when I had the K open, it was switched on for more than an hour or two. I didn't notice much heat from the PSU, I found more heat at the motherboard.

@NavidSyed: from my experience, the Atom indeed doesn't need any cooling, but the chipset needs! My home server runs on an Atom-board, and it has a simple heat spreader on the CPU but a 4500 RPM fan on the chipset.
The K has a different chipset (newer), but I think the problem is similar. This one has a big heat spreader over multiple chips and is generally designed for fanless operation, but according to the manual there should be an air flow through the heat spreader, which means the board should be mounted vertical.

In the Kronos the board is mounted horizontal and top down, which IMHO isn't in the range of the specs.

Btw., I didn't think the LCD will get hot by itself, but the heat from the other parts may be harmful for this unit, if not ventilated around. But I don't know much about LCDs and their heat sensitivity.
At least my computer monitor is much warmer than the Kronos display with the fan switched off.

[aribo61]

For the last hour, I used my Kronos to check, where the hot spots appear.

First of all, the spot isn't *hot*, but it's at may be 30°C.
I had to wait the whole hour to detect it clearly.

The main spot is clearly right of the tempo knob, the whole area from above I-F and I-G down to both sampling buttons (I think that's the area of motherboard spreader) get's a little warm.

At the number field (PSU area) the temperature increase is barely noticeable.

The LCD seems to be a little bit warmer than the metal case, but I think this is just because of the non metal material which feels generally warmer than metal.

The left side is completely cool.

[note I have a K61, for other models the positions may be different]

Btw, I never got any fault of the Kronos sound or else since I disconnected the fan.

[NavidSyed]

hmm, I disagree... First, the fan doesn't generate air flow through the PSU, but aside from it. I don't think it can keep the PSU cool.

exactly my point, fan is moving the heat away from the PSU that's how these fans are suppose to work.. if what you are saying is correct that chipset is getting hot that placement of the fan is inappropriate, it should have been close to the motherboard which it isn't I still think that primary function of the fan is to keep the PSU cool, just my personal opinion..

[aribo61]

but the PSU *is* cool (with a disabled fan), at least "measured" by hand at the outside area above the PSU.

Look, I am operating my home server with a standard 350W PSU (didn't get a cheap one with less power, so I took an older PSU from my fundus). But the computer dissipates <40W, that is about 10%, so I disconnected the fan in the PSU. Then I get an air flow about 35°C coming out of the PSU, but it works well so far.

The Kronos dissipates <60W (see near power plug).
The PSU board in the Kronos seems to be rather large compared to the one in my server PSU. And the Kronos PSU is mounted on a kind of heat spreader:

https://picasaweb.google.com/1085100000 ... 7450574130

I checked the pictures again, especially this one:
https://picasaweb.google.com/1085100000 ... 7156566146

As you see, the fan air flow should go half through the PSU.
The semiconductor parts which need cooling are mounted directly or indirectly to the other metal sheet (at the bottom of the first picture).
I think, if I would place a fan to maintain cooling of the PSU I would have mounted it more to this side of the PSU and I would have placed it directly at the PSU not at the SSD.

The picture pushes me to assume, that the engineer had a more general air flow in mind when placing the fan.

[maphill]

I have. Details in this very thread.

More details soon.

Mark

[aribo61]

... now after about two hours, the outside temperature at the hot spot is about 35°C ... and the PSU area didn't get warmer ...

[curvebender]

I am returning my 61 to the store, and they're going to send it to Korg and have it examined. (I listened to another 61 in the store, and it didn't make half the noise!)

According to the Korg rep, it's probably something inside that isn't tightened properly, thus causing the excessive vibrations. If that's is so, it will be an easy enough fix.

And since it seems that there are as many customers who don't hear a lot of noise as there are who do hear it, maybe it's just as simple as bad QC or something.

I will keep you updated.

[aribo61]

half of the noise would not be quiet enough for me.

good luck...

[aribo61]

when I had my Kronos open, I checked reasons for the noise.

Generally, I think Korg shouldn't have done some things.

E.g. the bottom cover is tightly connected to the keyboard.
This connects keyboard noise to a big metal sheet, amplifying it.

If you open the Kronos, the keyboard isn't fixed. This way I cannot really play on an opened Kronos. This is bad for testing.

The fan is also indirectly connected to the bottom cover.

Korg could easily have generated an air flow through the case by having some holes in the bottom cover and at the back on the right side.
I get the feeling that the planned design went out of the limits at some point (especially to much heat), and they tried to fix it under time pressure.

The whole construction doesn't follow any rules for quiet operation.
It's just not designed with this aim in mind.

[curvebender]

half of the noise would not be quiet enough for me.

good luck...

LOL

I agree, a fanless instrument would have been ideal..

But I am sure my copy is extremely noisy, I'm confident that Korg will be able to at least make it a little better.

[QuiRobinez]

I've received my kronos 88 yesterday (finally), i was shocked by the amount of noise the fan makes. To be honest it's hardly acceptable.

I can hear the noise from more than 5 meters away, it's that loud. It's a lot louder than all my computers running in the studio. Normally i would instantly return it to the shop, but that would mean to wait another few months for a new kronos (i've waited 7 months for this model) so i still not decided what to do.

I love the keyboard action and the sounds of the kronos, but this build quality thing is a big failure for a workstation in this price range.

[curvebender]

To be honest it's hardly acceptable.

You don't have to be polite.

It's NOT acceptable.

[curvebender]

The whole construction doesn't follow any rules for quiet operation.It's just not designed with this aim in mind.

Mind boggling, considering it's a MUSICAL INSTRUMENT...