Korg Forums

Hi, I'll post this at the Logic forums too.

I've just bought a Korg Kronos 2, and was very excited to get it connected to my iMac to start composing and recording music. What should be a very easy process is driving me mad with problems.

I will be using Logic Pro X as my DAW.

I have connected my Kronos directly to my iMac using USB, changed all the various audio inputs/outputs on the iMac system preferences, and checked everything using the Audio/Midi Setup utility. I have loaded up Logic, and changed the inputs and outputs to match my setup (Kronos as input, headphones from iMac as output.) The Kronos is recognised by Logic, and I can hear the audio from the Kronos through Logic fine, until I get blasted with massive white noise for a few seconds. This eventually settles down, but any short period of normal sound has pops and crackles. This is happening regardless of what I/O buffer size I've used, the process buffer range, recording delay etc. I have tried everything I can think of. I have changed the sample rate to 48 kHz to match the Kronos, and tried various latency settings.

-I have tried with and without the recommended and most current Korg driver.
-I have tried using Logic on my MacBook Pro, same problem.
I- have tried going via an audio interface, makes the problem even worse, sound becomes robotic too.

This also happens when using GarageBand.

I simply can't afford to have my hearing/speakers obliterated by a random and baffling thing like this, on what should be a simple and intuitive process to hear my instrument in a DAW.

I even resigned myself to using the headphone out jack of the Kronos via audio interface to iMac, which works great, apart from a constant pitch hum which renders that method useless too.

Please can someone help, I can't use my instrument until I get this sorted and I have spent days researching this on the web to no avail. I have no idea what to do or who to ask. Below is a list of my system setup-

iMac 21.5 inch, Late 2013, El Capitan
Processor 2.7 Ghz Intel Core i5
8 GB 1600 MHz DDR3
Using Logic Pro X

Thanks

are your audio inputs engaged? I have ran into problems (weird noises and such) at times because they were on and in the input volume being pretty high....

aside from that, it does seem like it could be a sample rate like issue...

So you are saying this happens even with a normal L/R cable plugged into an audio interface?

and through the headphone jack? (with no USB connected at all)

Hi apex, thanks for the quick reply - I'm not sure I know what you mean regarding the audio inputs being on; using the Mac system preferences I have selected Kronos as the input, and likewise in Logic. Do I need to disengage something?

The sudden white noise issue doesn't happen when using the headphone out of the Kronos, but it has it's own noise issue which I can't eliminate either.

I have tested the L/R outputs of the Kronos and the same problem occurs.

I have also checked the cpu usual of the Mac and have nothing else running in the background.

Sample rate has been set to 48 kHz

Thanks

MisterGee wrote:Hi apex, thanks for the quick reply - I'm not sure I know what you mean regarding the audio inputs being on; using the Mac system preferences I have selected Kronos as the input, and likewise in Logic. Do I need to disengage something?

The sudden white noise issue doesn't happen when using the headphone out of the Kronos, but it has it's own noise issue which I can't eliminate either.

I have tested the L/R outputs of the Kronos and the same problem occurs.

I have also checked the cpu usual of the Mac and have nothing else running in the background.

Sample rate has been set to 48 kHz

Thanks

Ok what I meant was that there are two audio inputs on the back of the Kronos... make sure they are turned down all the way/off. (just for the same of process of elimination)

wow... so you get bad audio DIRECTLY from the main outputs? with NO COMPUTER in the chain at all?

I think a few series of iMacs and Powerbooks have issues with USB audio. There should be a few threads on the forum about it and I'm sure google will also turn up something. Have you tried switching USB ports or putting a USB hub in between?

Ah sorry, no, the computer is always in the chain, but when taking the audio from the headphone socket (or L/R outs) to the Mac via audio interface, I get the constant whine in the background. The white noise issue (which worries me the most) comes from the audio outs on the back of the Kronos via USB.
It's worrying because it just seems to happen at random, just when things appear to be working fine.

I've checked an the 2 knobs in the back of the Kromos are at minimum, and the 2 buttons are depressed to 'line in'.

just plugging in headphones to the headphone socket on the Kronos works fine, so I'm pretty sure the issue isn't with the Kronos itself.

SanderXpander - I have the M-Audio M-Track interface/hub, and that makes the issue worse (the robotic sound I mentioned in the op).

I haven't tried switching USB pots in the Mac, it didn't cross my mind as to whether that would make any difference! I'll certainly try that, thanks.

The whine is a ground loop issue. You could cut the ground on the USB cable from the Kronos to the computer, try hooking up the Kronos to the interface via TRS cables and NOT connecting the USB to the computer, or experiment with different wall sockets. Ideally all interconnected audio devices should be hooked up to a single wall outlet via extension boxes in a star pattern. Though this doesn't always solve the issue if the equipment itself is badly grounded (computers are notorious).

Thanks-so I connect the Kronos to the interface using TRS, and then the interface to the Mac using the USB, or with another cable?

Yeah the interface has to be connected to the computer. I just mean then DON'T also connect the Kronos to the computer with USB. Hopefully this will fix the whine although grounding issues can be really tricky to track down and fix.

Ok thanks.

Still going in direct via USB tonight, and I thought things were going great until the white noise thing happened twice. I need to find the reason for this.

Thanks

it's as if the input via USB of the Kronos suddenly maxes out and causes the input meters within Logic to distort like crazy for a few seconds, and then it returns to normal for a while.

I wil seriously need to think about selling the Kronos if I can't get this resolved, I simply can't use it for the reason I bought it.

Is the Kronos the only USB audio device connected to the computer in that scenario or are you using an aggregate device?

Again, some iMacs and Powerbooks have problems with USB audio (I think late 2013 models but I could be wrong), it's not just the Kronos it's the Mac USB subsystem. There should be some threads about it on this forum.

Yeah it's the only USB audio device connected, no aggregate device.
The same issue happens with my MacBook Pro, and that's an earlier year model.

The issue seems stable when first loading up/rebooting Logic, I played for a good 30 minutes without the problem, but changing some of the audio settings (latency etc) within logic seemed to upset things and the issue started up again.

But I can't risk my ears when this happens, it is horrifically loud, and I'm reluctant to use it now.

I was suggesting taking the computer out of the chain completely... just to eliminate that something was wrong with the Kronos outputs.

Do you have the USB outs turned on? (a lot of people forget about that in the Global menu under the audio tab)... check that out too.