Hi there, I’m using two Focusrite firewire audio interfaces and one Focusrite USB interface with my Mac which is running OS X 10.6.8 and I can’t add any more Focusrites according to their tech support. I’m running out of inputs so I need a new audio interface and am considering a UR22MKII based on all the good things I’ve heard and read about them. Is anyone out there using a UR22MKII with Mac OS X 10.6.8? I see that the latest firmware 1.03 is compatible with 10.9.5 or later. But I do see an older USB Driver 1.8.1 which is compatible with Mac OS X 10.6.8. Any help would greatly be appreciated. Thanks in advance.
hi shumpky
you can run the ur22 mkII without the loopback funktion with the osx system core driver, like i do, because with the drivers steinberg drivers 1.8.1 to the new 1.9.10. on my 2008 imac it produces nasty dropouts and i´m not the only onewith such a problem here in this forum. steinberg support wrote that they never heard of such a problem problem!.
i even tried it on snow leopard but only witrhout the steiberg divers the probs are gone.
you have to uninstall the steinbergyamaha driver with the their unsinstaller and there you go.
but you won´t be able to use the loopback funktion and you have to adjust the laterncy a bit. this is what i found out with the ur series, and m-audio seems to have those issues as well.
i like the hardware a sound very much, but there a many problems, like many other has with older macs and the yahama/ steinberg usb drivers. at it seems to get whorse with ervery newer apple os.
my solution is to work with el capitan and the core driver. i discoverd this solution a view das ago and i´m not sure how it will work with while working with this combination., and mayabe other problems will occur.
with my experiance, i would now look for another brand. maybe zoom, or even the new beringer interfaces seems to be really good. take a carefull research if you decide for a brand and model an search for problems withh you current system and for your upcoming system.
i learnd my lessen very hard the last weeks and month.
i hope you´ll understand what i´m trying to say here in this language. 
greetings wänä
Thanks for your reply and sorry it took me so long to respond back, I’ve been away.
So you’re saying that I can use the UR22MKII in what they call “Class Compliant” mode (I think) with Mac OS X Snow Leopard 10.6.8? That’s how I use my Focusrite Scarlett 2i2 – no drivers at all, it just works when you plug it in. I do not need to use the loopback function at all.
I wouldn’t be able to adjust the latency without installing the software, though. The latest software version that works with Mac OS X Snow Leopard 10.6.8 is the Yamaha Steinberg USB Driver 1.8.1 (October 29th, 2015) but it only supports the UR22 and not the UR22MKII.
Don’t know if Yamaha Steinberg USB Driver 1.9.4 (November 2nd, 2015) will, in fact, install on Mac OS X Snow Leopard 10.6.8 even though it specifies Mac OS X 10.7.5 to 10.10 as being a requirement (M-Audio used to do this but you could still successfully install the drivers on some older systems outside of the specified requirements).
Has anyone else had any latency problems with the UR22MKII? I don’t have latency problems at all with any of my existing audio interfaces (Focusrite Scarlett 2i2 via USB and two Focusrite Saffire Pro 24s via FireWire). In my experience with Mac OS X, I find Mac OS X Snow Leopard 10.6.8 to be the least problematic out of any release.
sorry for my very late response.
yeah, snow leo was the most famose os for media work for many people, like me the best ,mac os.
i´ve run snow leopard from an external fw drive an tested it with the ur22 mk2 with different drivers. i was able to install older drivers from steinberg with snow leo. it worked but you will not get the loopback funktion to work.
with the steinberg drivers all my daw´s garageband, cubase 8ai and reaper were spot on with the latency correction. with the core driver i have to adjust it a bit.
you can uninstall the drivers any time. so try out for yourself.
oh, ant the larency on my system is a tiny bit better with the class compilant mac core driver.
if i knew what i know now, i would have stay away from steinberg hardware. many people have problems with it, with mac and windows and the answers from the support can make you really angry. they don´t read what you wrote, they only give the same, not working advises, over and over again. 
greetings and i hope you have found a solution.
next time i will go with zoom, focusrite or maybe the behringers.
I got a Steinberg UR22MKII for Christmas today and I must say that although it did work with Snow Leopard (without any additional software installation), it is a very poor piece of equipment. Terribly noisy in comparison to my Focusrite Saffire and Scarlett interfaces. It is going straight back to the dealer tomorrow. I will never use a piece of Steinberg hardware again as a result of this.