As I am a customer for years now, buy all my computers @ apple, I must say... Its for a reason.

I could swap my iMac with a full SSD Version. And voilà: All the problems are gone.

I tried everything. So to say.

The only solutions are:

- Get a new iMac / replace it, go to an apple shop and tell your story

   I will remain a good customer, and any penny I may spent more than a windows pc, was worth it once more!

- Install it like mentioned above. DON'T use the Fusion Drive

  external Thunderbolt Drive

  or new Partitioning for your Drive

- Apple provides a fix one day

  We are not the mass market, be aware

greeez

DONT GIVE UP HOPE!!!

EMAIL UPDATE FROM FOCUSRITE

"I understand your concern and we're working on making all our mac-compatible products compatible with OS 10.9 (Mavericks). Where the solution requires working with Apple or another 3rd party, which is mostly the case, we are unable to provide a time line to compatibility. Where we can provide a solution independently, we will provide a time frame. We are working on Mavericks compatibility now, and have been for some time.

We have recently realigned our priorities in terms of available resources, and are creating additional resources to ensure smooth operation with new OS releases for all our OS-dependent products . This is now our top priority, ahead of new product development and all other development requirements. We apologise for the inconvenience and stress that not providing a solution sooner has caused. Our goal now is to deliver a zero time gap for compatibility with new OS releases."

Mike Towns  //  Focusrite Technical Support Engineer

Also...

I called focusrite yesterday and they reccomended me to go to beta.focusrite.com and download the mixcontrol 1.7 beta driver,

Scarlett MixControl 1.7b1Released on 10-07-13 11:57

Updates 6i6, 8i6, 18i6, 18i8, 18i20 firmware to r608.

- Fixes level spike when opening ScMC with monitor level turned down
- Fixes problem where an excess of MIDI data can cause units to become unresponsive

Downloading the firmware update from my Macbook pro to my 18i6 has made the sound of my Scarlett 18i6 Audio Interface a lot more bearable. However, the problem has changed from the sound randomly deciding to distort until there is literally no sound left (Until I unplug and replug the Scarlett’s USB cable), to frequent clicking and popping… My studio is still severely crippled by the Mavericks/scarlett compatibility issue..

I would suggest you guys try it out!

Understand the potential problems that could be caused by a beta (Lol that made myself laugh when I thought about it)

late 2012 13.3" non-retina macbook pro,

1.9 i7

8gb ddr3 1333

500GB HD (non-superdrive)

Hi guys, here is an update from my side.

I had bought a new Imac couple of weeks ago I7 16GB Ram and 1TB Fusion Drive. I also got a new Line 6 Audio interface UX2. I was running Mavericks and installed the Line 6, it has been a drama. Sound clicks, pops, distorted sound and more frustrating huge amounts of latency (no complete sound drops though like many people here). I use this set up for guitar recording and it was impossible to do so. Spent quite some time with apple care that was starting to get more and more calls in filing the same problems. All with Fusion Drive. We had tried many things with apple care but no luck, allthough they where friendly pacient and willing to help.

There are still some people that are concerned about mavericks and interfaces, many people have tried partitions on the fusion drive and so.. I have changed my Imac and now got one with 3TB ATA drive. This time the Imac came with mavericks so decided to install the line 6 drivers again and this time it all works perfectly.

I was concerned about the Fusion Drive but also about audio interfaces USB 2.0 not being 100% compatible withh the new USB 3.0 ports on the Mac. Today I can say that for me it all works with no problems at all. Mavericks, USB 2.0 audio interface and it works!!!!! Finally.

For me I can now clearly say it is the Fusion Drive and not the USB 2.0 USB 3.0 or mavericks.

Hope this helps anybody out there that is still hasitating whether to change their Imac FD to regular drive.

I must say that maybe Line 6 was better prepaired for mavericks so take that in mind.

We are in the same boat. Currently running a 2013 iMac 27" with fusion drive. We havent yet updated to mavericks either so we think this takes that out of the equasion.  We where using an Maudio Profire2626 originally but this went out the window stright away with lack of drivers available. Luckily we had an NRV10 hanging around and found that it worked great.

Now the last couple of weeks we've started to see drop outs more regularly. This can occur after hours or minutes of ussage. We find switching off and on can delay any further dropouts. However in the last two weeks we've noticed a big increase in down time due to drop out after drop out and eventually the Mac stops 'talking' to the audio interface. Its becoming a real problem and as a working studio this can only mean bad things for us.

Having read a lot of threads about it, we are unsure to where the problem lies. Is it the drivers or infact is it the iMac. In this case we'd be **** out of luck swapping to any interface. We are really disappointed in both Apple and interface manufacturers for lacking in solving the problem.

We look forward to reading anyones input on solving the issue.

A little late to the party here. I have an iMac 2013 with 3 TB Fusion drive running Mavericks. I'm having problems with all USB headsets and microphones. I have a Logitech H650, Griffin iMic and Blue Yeti. None of them work properly on this machine, but they're fine on my Macbook Air running Mavericks.

From reading this thread and others, it seems to me that the problem is the combination of Fusion Drive, Mavericks and the iMac 2013 (with some exceptions). Most people running Mountain Lion with the 2013 iMac and Fusion Drive don't seem to have the issue, or at least it's less severe. With one possible exception early in this thread, I haven't seen anyone with a pure SSD iMac complaining of this issue, regardless of what OS they're running. And it seems to be far more common on the 2013 iMac than older models of the iMac or other Macs.

Is that accurate? I'm trying to decide what to do with mine. I'm outside of the return period, so I doubt Apple will give me a refund. I don't really want a pure SSD iMac, because then I have to buy an external Thunderbolt RAID to house my photos if I want to achieve similar transfer speeds to what the Fusion Drive offers. I don't really want to partition my Fusion Drive for the same reason. If downgrading to Mountain Lion will solve the problem, I'm more than happy to do that. I'm not that impressed with Mavericks anyhow.

So how many of you are having this issue with Mountain Lion? In this thread it seems going back to ML solved the problem for most, though it may be a slightly different problem than what is reported here.

Apple, if you are reading, please fix this major issue!!!

Just to further prove it is in fact the Fusion Drive:

I just bought a new

27" iMac

3.4 GHz Intel Core i5

16GB 1600 MHz DDR3

3TB Fusion Drive

OS X MAVERICKS

and the audio cuts out in Logic Pro X and Pro Tools 10 with my Avid MBox Pro 2 AND Digi 002...

I still have my old

24" iMac (Early 2008)

2.8GHz Intel Core 2 Duo

4GB 800 MHz DDR2 SDRAM

750GB SATA Disk

OS X MAVERICKS

and both hardware and software work 100%...

-------------------------------------------------------------------------------- --------------------

Does any one think there may be a fix in the next update 10.9.1 or 10.9.2???

Any developers out there that have access to 10.9.1 yet?

http://www.macrumors.com/2013/11/21/apple-seeds-new-build-of-os-x-mavericks-10-9 -1-beta-to-developers/

The 10.9.1 update improves the stability and compatibility of your Mac, and is recommended for all OS X Mavericks users.

The update includes the following fixes:

- Improved support for Gmail in OS X Mail, and fixes for users with custom Gmail settings

- Improves the reliability of Smart Mailboxes and search in Mail

- Fixes an issue that prevented contact groups from working properly in Mail

- Resolves an issue that prevented VoiceOver from speaking sentences that contain emoji

- Updates Shared Links periodically when open in the Safari Sidebar

- Improves compatibility of the VPN server in OS X Server

These bullet points are just just a few fixes obviously... but there may be a more in depth description on this update somewhere...

I just got off the phone with Apple Tech Support and they fixed my problem, but we couldn't figure out what exactly fixed the problem.

I'm using Focusrite Scarlett 18i8 USB, Logic X, iMac Late 2013.

things that could have solved problem:

re-installed latest drivers

rebooted computer

played music in iTunes

tried recording in Garageband

working now, I will post again if it stops working....

calling Apple Tech support solved my problem, they were very helpful.

800-275-2273

What are your specs BonJamesBon? Do you have the Fusion Drive?

May only work for a few minutes if it is the Fusion Drive...

Update:

Got a response from a developer that 10.9.1 (that will be released in the next following weeks) *WILL NOT* fix the Fusion Drive issue... Crossing my fingers for 10.9.2 !!!!

Adam: that implies that Apple is aware of and working on the Fusion Drive issue? Are we certain of that?

Pretty dispiriting to have to wait another ??several months for 10.9.2 for this to be fixed.

iMac 27-inch, Late 2013

Processor  3.2 GHz Intel Core i5

Software  OS X 10.9 (13A603)

3TB Fusion Drive

adam swink, you think it will only work for a few minutes on the Fusion drive? 

It's been an hour since the fix.

TEsting....

Just recorded for 10 minutes, no issue.

Exactly what is the that you are running?

It should have said what test are you running.

BonJamesBon,

Thank you for posting this. I'm now thinking this issue will be addressed by the hardware manufactuers, not Apple... I went to Focusrite and saw this:

http://global.focusrite.com/answerbase/using-a-scarlett-interface-on-osx-109-mav ericks

Other audio companies will probably follow...

I wonder if the same applies for USB headsets and microphones (like the Blue Yeti)?