APC40 creating high pitched noise

[toph]

Hmm, mine is from August then. - But what still makes me wonder is why one and same product has two different UPCs (Universal Product Codes)? - Maybe there is more than one "manufacturing street"?

What I wold like to know is, if Spazi really took his unit to the radio mechanic and when he did so, if the mechanic was able to figure out the problem or to fix it.

[Akshara]

Btw, my unit has the 825213 00238 UPC code and was made in 07/09.

[Akshara]

I edited my original post, yet wanted to post my findings here separately.

So just ran some basic tests, and basically it makes no difference whether the APC40 is connected directly to my computer or to the powered USB hub, with bus powered devices or not. However when I run the MT Player with NativeKontrol's plugins the sound disappears completely, and this is repeatable and consistent, at least with my system here.

Here is what I did..

1. Started with the APC40 turned on, not connected to the computer, running in demo mode (moving light display) and the unit's environmental running noise had a very noticeable and loud high pitched frequency that modulated as the LEDs turned on and off.

2. Connected the APC40 to the MBP directly (the MBP running on wall power) and the high pitched noise continued, emanating from the Track Selection LED and from behind the Device Control knobs.

3. Connected the APC40 to the powered USB hub, connected to the MBP, with no bus powered devices, and the high pitched frequency continued exactly the same.

4. Connected the APC40 to the powered USB hub, connected to the MBP, with several bus powered devices connected to the same hub, and the high pitched frequency continued.

5. Opened Ableton Live with a basic session and the APC40 at default and the frequency continued.

6. Closed Live, opened the MT Player with NativeKontrol's CL2+TC2 enabled, opened Live and the frequency completely disappeared. Switched between all of the CL2 modes, no noise at all.

7. Closed Live and the MT Player, keeping the APC40 set in Navigation Mode (most of the LEDs enabled) and the APC40 still emitted no frequency noise at all.

8. Powered off the APC40 and then powered it back on, and the high frequency returned, from the Track Select LED and the Device Control knobs just as before.

9. Opened Live with a basic session and the APC40 at default and the high frequency continued.

10. Closed Live, opened the MT Player with NativeKontrol's CL2+TC2 enabled, opened Live and the frequency completely disappeared... again.

So this is why I haven't noticed the high frequency noise lately. For some reason, and I have no idea why, the NativeKontrol plugin is disabling the high frequency.

[jbone1313]

Hey Akshara-

Thanks for the detailed tests. I have no idea what conclusions to draw from that, really. Obviously, that particular configuration is causing whatever's producing that noise to chillax.

I might take the thing to the local electronics shop and see what they can do.

This blows. Its such a great device, and such a horrible noise!

[toph]

The nativeControl-thing is interesting!

Mine also starts heavy buzzing when it is connected to Live and the loudest hiss is present, when the pan-encoders are all on zero. When I move those to left or right positions hiss gets more silent and also when I switch the encoders to effect sends with zero.

It seems that the hiss has to do with the LEDs, but as your experience is, it seems to stand in relation to the active connection to Live. - My unit is buzzing less loud when the "disco-mode" is running while the unit is powered but Live is not started.

But as I don't know how hardware like the APC works under the surface, I've no idea, what is the real cause and how to elimate it.

[Tone Deft]

my guess is that the MT Player changes the rate at which the LEDs are blinking.

on the Launch Pad and APC the LEDs aren't held on, they're strobed very quickly. try this... sort of relax your eyes then scan them across the device, you'll see the pads go on and off. OR take a camera and take a picture as you scan it quickly across the LEDs, the picture should show individual boxes. do that before and after the MT Player (w/ and w/o noise) and see if there's a difference.

your local electronics repair person would probably LOL if you asked them to fix this for you.

[Akshara]

@jbone1313

No problem. The noise really bothered me at first too, to the point of almost sending it back. I'm using it in a studio and that kind of noise at the mixing position is simply not okay. However it went away, and so I forgot about it until this thread popped back up. Never connected that I'd started using those plugins around the same time. I have no idea what to make of that either. It does imply that it is something which could be fixed via software. In any event, I hope that you find a solution.

[jbone1313]

your local electronics repair person would probably LOL if you asked them to fix this for you.

They very well might. I'm a computer expert, but a moron when it comes to electronics.

It can't hurt to ask, I suppose--even just for my knowledge and edification.

It may just be how it is, I guess.

It just seems surprising that a professional audio device would emit such noise. Its clear that it bugs quite a few people, so I don't think I'm just being nit picky.

[Sly One]

I really look after my ears. I noticed the signs of fatigue at that frequency after using the device for a couple of hours last night. It got turned off immediately; a few weeks of that and I wouldn't hear it anymore, or anything else in that range.

No way Jose.

It's going back. If there's even a slim chance of finding a unit that doesn't squeal, I'll take it. Really worried that this is just a design flaw though and I'll have to return it. That would really really suck.

[Sly One]

By the way, if this helps anyone get on the right track, I had exactly the same problem with a PC motherboard. It turns out it was a known issue with a couple of the little solenoids on the board. A larger solenoid emits a hum, but these tiny little things were squealing when they vibrated.

I had 3 replacements and they *all did it*. It was a basically low-quality component. I am quite concerned that we might have the same issue with the APC-40.

There is no way after spending a fortune creating a silent, hi fidelity listening environment that I am going to introduce a squealing toy into it.

[jbone1313]

I really look after my ears. I noticed the signs of fatigue at that frequency after using the device for a couple of hours last night. It got turned off immediately; a few weeks of that and I wouldn't hear it anymore, or anything else in that range.

No way Jose.

It's going back. If there's even a slim chance of finding a unit that doesn't squeal, I'll take it. Really worried that this is just a design flaw though and I'll have to return it. That would really really suck.

Its very interesting to me that you bring this up. I thought the same thing! The noise is fatiguing! I'm glad you mention this; I'd like to hear others' take on that.

I even went as far as to try to research whether or not high frequency noise at low volumes is harmful. All the info I've read talks about volume of noise being the culprit.

But, my ears are telling me this might be harmful.

Might a product recall be in order?

[Sly One]

Definitely trust your own ears. I was getting that "numb" feeling in that frequency range when I turned my ear away from the sound; that is, my ear had compressed that frequency.

Remember that high frequencies don't have to be very loud in terms of SPL. A bass sound at 120db sounds fat. A scream at that would make your ears bleed.

[Sly One]

Might a product recall be in order?

It'll never happen. Too many people just don't care or can't hear it. If enough of us return them though, they might fix it for the next batch.

Assuming of course that it's not just some units. I'll soon find out when I take mine back.

[jbone1313]

Well, I already swapped mine. My new one still buzzes.

[Sly One]

Damn damn damn

Time for an email to Akai.