I mostly record VSTs in the box.I track only vocals through the mic and may be one or two instruments at times. I have latency issues with my Scarlett and also hear about the stunning quality pres. The price difference is significant so I want to make sure I see a significant benefit of upgrading to either the babyface or UCX beyond of course a lower latency ( seeing 10ms right now)
I would like to validate my understanding :
1. Since I dont record live instruments much , I'm assuming the DSP fx on the UCX is not so useful for me.Is this correct ?
2. My work is heavily vocal centric so I'm hoping to hear better clarity in the vocal recordings? Is it a reasonable assumption?
3. In case I need more inputs in the future the adat input will have me covered.
4. If I have to connect a second pair of monitors I think I will need the UCX since the babyface has only 2 outs for the monitors.Not possible without a monitor controller right now.
5.Will I hear a difference in sound from the VSTs ?...in terms of clarity ?If I produce a piece of music completely using VSTs..bounce a wave file and play it on an external system..to what extent does the audio interface used to bounce the wave file have an impact on the sound quality on such music?
 
 
Thanks in advance.
 
 
 
 
 
 

1. Since I dont record live instruments much , I'm assuming the DSP fx on the UCX is not so useful for me.Is this correct ?
The DSP effects are useful for monitoring with effects during tracking, without printing them to tape. And if there's a good compressor included then that's also handy. They are not a deal breaker , other things are more important. 

2. My work is heavily vocal centric so I'm hoping to hear better clarity in the vocal recordings? Is it a reasonable assumption?
Yes, I would hope so. I'm not a fan of my Scarletts pre amps so I bought a Joe Meek 3 Q.
Down the road I am looking at the Tascam uh 7000 just to get the better pre amps.  Most of those $600 plus interfaces have much better pres than the Scarletts which are consumer grade at best. 

3. In case I need more inputs in the future the adat input will have me covered.
Yes, but then your spending big money on the device to make that happen. If you truly think you need more inputs in the future,  then you should purchase an interface that has what you need now. 

4. If I have to connect a second pair of monitors I think I will need the UCX since the babyface has only
2 outs for the monitors.Not possible without a monitor controller right now.
My above statement again. Make sure you get what you need in connectivity. Why spend the money again and again to get what comes almost free on the right device. 

5.Will I hear a difference in sound from the VSTs ?...in terms of clarity ?If I produce a piece of music completely using VSTs..bounce a wave file and play it on an external system..to what extent does the audio interface used to bounce the wave file have an impact on the sound quality on such music?
 
None. You could unplug your Scarlett and export an audio file it will be the same. It's all number crunching done your CPU and the software. An audio interface is for getting the audio in and out. It has nothing to do once the audio is ITB 
 
Here's my shopping list to ponder: 
 
What kind of connectivity do you require? and how many of each.
These are some of the options:
XLR, 1/4",  Combi jacks,  RCA, ¼” line level, ¼” Instrument level ,MIDI, SPDIF, ADAT,MADI
How many ins and outs do you think you'll need now and in the future?
Are they accessible?  Front or rear 
Are all ¼” jacks Balanced?  
Is there a true stereo pair? Some don’t have a matched set of inputs.
Pre Amps will fall under the “you get what you pay for”  rule, but check out the reviews anyhow.
A/D convertors will also fall under the same rule and generally all are good these days.
Are there peak level meters or just a little LED for each input?
Are there channel Insert jacks?
Are there separate controls for Monitor level and headphone level?
Is there a blend control for mixing Source with Computer ( DAW) ?
How many Headphone jacks? A level for each?
Are the input pads or line / Instrument toggle switches on the front, back or software controlled?
Is it a metal box or cheap plastic? Is it light and portable or large and bulky, Rack mountable?
Does it have an on / off switch?
Does it use Buss power or a power supply? Buss power can have issues with noise and Phantom power. Look for at least an optional power supply.  
Does it have DSP effects built in?
Does it use a GUI mixer? Having a software (GUI) mixer adds more options.
Can it be used as stand alone? Some interfaces are also handy as a small mixer.
What are the Round Trip Latency (RTL) specs? Do you need low RTL for real time processing?
Low RTL is going to be at a higher price point. A $200 interface will have hidden buffers etc.
Zero Latency monitoring is not the same as RTL. All interfaces have some latency.
Zero latency is just marketing hype for monitoring directly from the interface.
And most important of all, Does it have top notch drivers for your OS. 
What is the word on support from the company?
Does it come with free software, An LE version of a  DAW you would like to try?
 
Everyone will recommend the interface they have chosen, that doesn't mean it is the right one for you. 
 

RishiS
...If I produce a piece of music completely using VSTs..bounce a wave file and play it on an external system..to what extent does the audio interface used to bounce the wave file have an impact on the sound quality on such music?

 
None (as Johnny said). However it will sound clearer while you are monitoring. Your mixes might improve as a result.

Kev999

RishiS
...If I produce a piece of music completely using VSTs..bounce a wave file and play it on an external system..to what extent does the audio interface used to bounce the wave file have an impact on the sound quality on such music?

 
None (as Johnny said). However it will sound clearer while you are monitoring. Your mixes might improve as a result.

Thanks , that helps.

Cactus...thanks for the awesome check list !
 

Cactus Music
3. In case I need more inputs in the future the adat input will have me covered.
Yes, but then your spending big money on the device to make that happen. If you truly think you need more inputs in the future,  then you should purchase an interface that has what you need now. 

Ok...that is a valuable piece of advice I overlooked.
 

Cactus Music
4. If I have to connect a second pair of monitors I think I will need the UCX since the babyface has only
2 outs for the monitors.Not possible without a monitor controller right now.
My above statement again. Make sure you get what you need in connectivity. Why spend the money again and again to get what comes almost free on the right device.

I have a related question here. Some interfaces have a pair of output called " mains " and some just have balanced line outs. What is the difference between the two ? If I plug the main monitors to the mains and the second pair to line outputs (say 3 and 4), would that be ok ? I am assuming I will have to calibrate the levels on all the four monitors to a standard spl using an spl meter. And for interfaces which do not have a pair designed for the main monitors, am I losing out on something ? The UFX has a pair of XLR outs for the mains and the UCX has all TRS line outs, nothing specifically labelled as mains.
 
 

Cactus Music
 
Is there a true stereo pair? Some don’t have a matched set of inputs.
Are there channel Insert jacks?

For what kind of applications will I need these? I have always tracked in mono and bounced to stereo if needed.
 

Cactus Music
How many Headphone jacks? A level for each?

I acutually need 2 headphone outs but I am seeing more than one headphone outs only on the high end interfaces which are out of my budget (like the UFX). The babyface has 2 of them but the I/O on it may not be future proof for me. I was trying to avoid spending on a monitor controller for this purpose and for additional pair of monitors.
 
 
 

I have a UCX with an Audient ASP 880 in the ADAT. I like it, but I record more than vocals.

If you don't already have a Mic you Love, you might be better off spending your money there.

The FX on the dsp of the RME are awesome. I use the expander more than compressor, but the EQ most. Don't be so sure this will not be of value to you. I use the EQ when mixing all the time. I have different favorites that help me imagine how it might sound in different places. You can do this in sonar, I do it in the RME.

Remember too that you get DigiCheck with your device. Read about it. I love it and used it recording a band last night.

BABYFACE has 2 headphone outs,
separate mixes available for each.

gswitz

If you don't already have a Mic you Love, you might be better off spending your money there.

The FX on the dsp of the RME are awesome. I use the expander more than compressor, but the EQ most. Don't be so sure this will not be of value to you. I use the EQ when mixing all the time. I have different favorites that help me imagine how it might sound in different places. You can do this in sonar, I do it in the RME.

I have shortlisted a few mics already almost zeroed on the Neumann Tlm 102.
What did you mean by ' you can do this in sonar'. Can I use the rme fx to mix in sonar? The way I understand this is that I can use these fx while recording thru the inputs on the RME but then the recording is 'hardcoded' with the fx forever.

EASIEST WAY TO LEARN:
 
http://babyface.rme-audio.de/

The fx in the UFX can be "printed" to the recording or just sent to the monitor/foldback. Totalmix is essentially a high-end digital mixer with a huge range of routing possibilities.

As for XLR "main outs" vs TRS line outs they're the same thing with different sockets. Totalmix assumes the "main outs" will be the monitoring bus but it doesn't have to be. I use line outs mostly to send audio from the DAW to processors or synth audio inputs but I could equally well use them with monitors or headphone amplifiers.