clipping sound on new iMac when Logix X is running

erikhj & mats_j:

If you don't want to be drawn into the USB3 issue, you can circumvent the problem by using a firewire interface and connecting it to the thunderbolt slot via adapters. I use a Focusrite saffire Pro 14.

(btw: the 10.9.2. update hasn't resolved my USB problems: still I can't rely on the audio trasmission from my Korg Kronos into the Imac via USB)

I got a Universal Audio Apollo Twin with a Thunderbolt interface and it appears to be working fine.

Zeno_Muc wrote:

erikhj & mats_j:

If you don't want to be drawn into the USB3 issue, you can circumvent the problem by using a firewire interface and connecting it to the thunderbolt slot via adapters. I use a Focusrite saffire Pro 14.

(btw: the 10.9.2. update hasn't resolved my USB problems: still I can't rely on the audio trasmission from my Korg Kronos into the Imac via USB)

The USB2/3 issue won't likely be resolved by Apple as the issue itself relates to the design/implementation of USB on the external device and not the USB3 implementation by Apple... which is per spec.

USB2 devices that have this issue need either a new driver update or a firmware update from the device's devs...to correct the problem.

If such an update isn't possible because of the way the USB2 device was originally designed.. then, as other Devs have done.. the USB2 device's hardware itself needs to be updated with a better/correct implementation as per the USB2/3 specs...

Possible workarounds that have been reported as working with different degrees of success depending on the USB2 device involved... are to use a powered USB2 hub to connect the USB2 device to.. and then from there to a USB3 port on the Mac.... or to connect the USB2 device to a USB2/3 port on a Thunderbolt hub....

However, having said all that.... a client of mine is using a Kronos with a 2013 iMac with FD fitted.. running the latest Mavericks and LPX without issue.. so I suspect your issue is related to something else...

Hi The Art of Sound,

thanks for your post. I have been reading through these forums for quite some time now, and generally I have found your posts very competent and helpful. So thanks for making all these efforts in order to help others, it's much appreciated!

Form your earlier analysis of the audio problems I already suspected that the 10.9.2. update wouldn't be the cure for my problem (I have no FD). So I wasn't surprised or disappointed too much. I have tried a powered USB hub, of course, but without success.

It's interesting that you know someone who can run a Kronos with the 2013 iMac without troubles. At korgforums.com in the Kronos section there are 4 or 5 people who do have these USB problems, so the problem seems to be rare, but it is not unique. Strangely, in my setup the audio connection via USB sometimes works and sometime doesn't. It seems complete random and can change instantly (even in the middle of a recording, without me doing anything!).

Also, I have connected the Kronos to three different PCs without any issues. So all this points to the iMac as the source of the problems. But of course, both Korg and Apple are denying any responsibility. Both supports even say they don't know about the problem!

(I'll scrap the part here what I think about Apple as a customer who has bought his first Apple product, exclusively for making music).

By using the firewire interface via the thunderbolt slot I get things working fair enough, so I won't run the risk to send any of the devices (which one, they are both free of defects, according to their manufacturers) in for repair.

Only thing left to try out is to delete all drivers and run the Kronos as "class compliant" device, as was suggested in the Korg forums. I'll try that out when I have more time.

Sounds simple but I've just increased the buffer time to 1024 and it work fine... really really odd

HI GUYS MAN I DONT EVEN KNOW WHERE TO START BUT I BOUGHT MY IMAC 27INCH FUSION DRIVE AND HEARD CRACKS AND POPS WHILE PLAYING LOGIC AND ALL MY OTHER DAWS TOOK IT BACK GOT ANOTHER AND THE SAME ISSUE I CALLED THEY MADE ME REBOOT IT AND UNPLUG ALL MY EQUIPEMENT AND LISTE TO THE BUILT IN AND STILL THE SAME ISSUE AT THIS POINT I CAN ONLY SAY THAT THE NEW IMACS HAVE AN AUDIO ISSUE AND APPLE ISNT DOING ANYTHING TO FIX THIS ISSUE

IF ANYONE OUT THERE HAS A SOLUTION TO THIS PROBLEM PLEASE ADVISE

i even tried changing buffer size... nothing worked. its only been a week and 5 days and i havent been able to work on my projects at all

I returned my iMac27 with Fusiondisk and got a new one in return with SSD disk.

It works just fine! I have been testing and using it for several weeks and have no complain at all.
It just works as it suppose to do!

I use Logic Pro X with Apogee

Case solved for me.

What is the lowest buffer you can use with Logic Pro X and the Apogee interface?

I'm getting crakling at 32 samples with a Duet 2 but I have the fusion drive.