RME Babyface here, Solid performance with Sonar.
 
Rocky

Hard to beat the Lynx Audio stuff, great support and the quality of A/D is best bang for buck, pro level.

Thanks for the suggestions. The VS100 was working fine for me under Win 7 64 bit but under Win 8.1 sometimes Sonar doesn't find the device.  I have to make sure the device is on before booting.  It gets frustrating.  Under win 7 it was working great.
 
Thanks....

stxx
RME (UFX) - Solid as a rock, amazing quality and always works.   I've had Focusrite and Tascam and RME is by far the best.   Remember this:  You do get what you pay for.

Just sold my 2 x FF800s and bought an RME UFX with the ARC. Best money I've spent in years. Yes RME have some of the best gear going.

I second the UFX or any RME product for that matter.
 
Regarding the UH7000, I am intrigued by that for $400.  Would adding one of those to my UFX be an upgrade in sound quality?  I would use it for D/A conversion to main monitors and maybe headphones (although the UFX headphones are great.)  Does it have a facility to use an external clock, or should the UFX clock to the Tascam?
 
My UFX pres are all tied up with dedicated mics and I could use a couple more mic pres.
 
 
 
 

200bpm
I second the UFX or any RME product for that matter.
 
Regarding the UH7000, I am intrigued by that for $400.  Would adding one of those to my UFX be an upgrade in sound quality?  I would use it for D/A conversion to main monitors and maybe headphones (although the UFX headphones are great.)  Does it have a facility to use an external clock, or should the UFX clock to the Tascam?
 
My UFX pres are all tied up with dedicated mics and I could use a couple more mic pres.
 
 
 
 

I've worked w/ RME but not here at home.  The UH7000 is a step up from TC Konnekt, which I've always thought as = to RME for conversion and both a half-step below Lynx.  But any of 'em will get the job done.  Where the UH7000 does shine is the preamps - top notch. I like transformers but have no problem using them.  Top notch clean preamps.  At a pro studio here the owner thought they were worth the original list - $600, just for the pres.  He uses an SSL console and has 8 api channels.  And of course the preamps go through conversion before output, which gives you an idea of how good the conversion sounds.  The preamps should kick the RMEs.
 
The DA is nice - I use my unit the same way you envision it, tho I use it for AD too over my TCK (the 7000 has separate line inputs).  The 7000 can be switched via software for AES or Spdif - which carries the word clock.  I bought a lynx adaptor cable for sub $10 for AES to Spdif w/ my TCK.
 
If you are integrating it into a system digitally, you get all the benefits and none of the problems w/ high latency drivers (tho some claim usb 3 helps).  As far as sound quality, it is on a planet on its own for the price.  I wouldn't call it the equivalent of the lynx Hilo which some claim, but you can't do much better even at a much higher cost.  The Forté and Crimson and Baby face all cost more.  I'm not sure why Tascam is selling them so cheap, since they seem to be still producing them.  I can only think that the drivers cost them sells.  The hardware is superb.
 
@

Thanks.
 
I think the UFX pres are great, really loud and clean, I'd be surprised if the tascams are much better, but I do need a couple more channels and combined with a better output stage for monitoring, this looks like a no brainer.  The converters appear to be similar to Mytek in specs.  I don't have any problem with the UFX converters, but I'm curious if I would hear an improvement with the UH.  The UFX pres have more gain.
 
My guess regarding the price is that Tascam needed to make a statement entering the interface market; and this they most certainly have done.  The device itself is probably a compromise between low-end chinese manufacturing, a simple design (its a 2x2 interface in a full rack worth of space), and high end converters with little markup, combined with off the shelf low performing usb drivers.
 
I guess I would have to listen to it to really know, but I have suspected that the specs may be fudged or not tell the whole story, yet specs suggest it is on par with hilo.  
 
 

I just looked if I am reading correctly the UFX is 30 in Interface.  I just need 2 inputs 4 at most.
Probably a little overkill for my needs.
John

If you want incredible stability and functionality combined with great conversion, a Babyface plus the UH7000 would be hard to beat.
 
Just a Babyface alone would be pretty great.

There's a thread in the Hardware forum and the OP was having offset issues with a Tascam us1800. So I ran a test with my us1641 which is the same unit more or less and found the drivers are not reporting latency properly to Sonar. The OP was getting a 2,000 sample offset. 
I froze a drum track (Track 7)  and that was perfectly in sync with the midi,( track 6)  but the loopback audio was ahead by about 400 samples in both normal ( Track 8)  and High ( track 9) buffer settings. WDM ( track 10)  was late by 800 ms. 

 
I then ran the same test with my Scarlett 6i6 and it was Bang on every time. So which interface do you want to use for recording? 
I think people are mostly unaware that this is going on with some interface drivers and running the loop back test is a must. 
So any UH 7000 owners willing to try the test? I'm curious as that unit is of great interest to me too. But if the drivers are the same old Tascam drivers forget it.