SilverBlueMedallion
The back of the preamp has a BALANCED XLR output and a unbalanced TRS output.

 
If it's TRS (tip-ring-sleeve) it should be balanced (it's three wires just like xlr) or stereo.
So it's probably just TS (tip-sleeve) .
 
This thread might be a bit confusing to some since a jack in Britain = a plug in North America (where a jack is the socket).  Phone connector.

I stand corrected in my original post above. I edited it to be correct. Thanks.

mettelus
Okay, had to look both of those up, looks like the UR22 does have a switch in the combo connector to know which type is being used. You are correct that you will be double-amping that signal using the XLR input. Depending on how it sounds, this may not be an issue as you can offset the amp by lowering input gain - may or may not be effective depending on how that pre-amp is coloring the signal.
 
Other option - Unbalanced cables are not heinous (is what guitar cables are), you just want to be careful to not run them for long distances in most cases. Do you have a 1/4" to 1/4" to connect the "unbalanced" on the TubePre to the Input on the UR22?

 
I could do unbalanced, I just always read I shouldn't for some reason.  
 
So never use an XLR to TLS cable?

This is the one I ordered:   http://www.amazon.com/gp/product/B00OWG4MV6?psc=1&redirect=true&ref_=oh_aui_detailpage_o02_s00
 
Im not sure if it is an "impedance matcher" as you stated earlier, not sure what that is either. :(

 
You want to connect the xlr output (balanced) of your tubepre to one of the the xlr inputs (balanced) on your UR22.
 
The 1/4" ts output on your tubepre is unbalanced and you should avoid using it.
 
The adapter you bought is simply a connector change (xlr balanced to trs balanced) and doesn't do anything on its own.  There's no use for it in this case, but adapters are always useful to have lying around so never a waste.
 

Paul P
 
You want to connect the xlr output (balanced) of your tubepre to one of the the xlr inputs (balanced) on your UR22.
 
The 1/4" ts output on your tubepre is unbalanced and you should avoid using it.
 
The adapter you bought is simply a connector change (xlr balanced to trs balanced) and doesn't do anything on its own.  There's no use for it in this case, but adapters are always useful to have lying around so never a waste.
 

Well for my Steinberg UR22 I need that cable as when you plug in an XLR mic, it is adding another layer of amplification, but if you use a TRS input, then it sees it as Line Input and doesn't add additional amplification, which can distort the signal.

I am forced to use this adapter, I just wonder what this statement means, as I also thought the cable does nothing but convert the signal:
 

mettelus
 By "XLR->TRS" you are referring to an "impedance matcher" I am assuming

An impedance matching adaptor contains a transformer and other bits so that e.g. a low impedance mic with and XLR connector can be connected to a guitar amp that only takes TS jack plugs and expects a much higher signal at its input. Blues harmonica players using a low impedance SM57 into a guitar amp often use them. Without the impedance matching the mic signal is too low to get a high enough output from the amp.
 
A TRS-XLR or TS-XLR adaptor that isn't impedance matching just connects the relevant plug connections to each other. Electrically its no different to just soldering a TS or TRS plug onto a balanced/stereo cable.

 
First of all, I just noticed that your inputs on the UR22 are combination XLR/TRS, but that doesn't change anything.
 

SilverBlueMedallion
Well for my Steinberg UR22 I need that cable as when you plug in an XLR mic, it is adding another layer of amplification, but if you use a TRS input, then it sees it as Line Input and doesn't add additional amplification, which can distort the signal.

 
Why do you think there'll be an extra level of amplification if you use the TRS hole ?  I'm pretty sure the respective XLR and TRS contacts are just wired together.
 

 

 I am forced to use this adapter,

 
I don't think so.
 

I just wonder what this statement means, as I also thought the cable does nothing but convert the signal:

mettelus
 By "XLR->TRS" you are referring to an "impedance matcher" I am assuming

 
I imagine mettelus is referring to a balanced XLR to unbalanced TS adapter like this one.  You don't need that either.
I've found them useful in electromagnetically noisy environments to permit running long balanced (xlr) cables instead of unbalanced 1/4" instrument cables.
 

I have downloaded the manual for the Steinberg UR22 and can give you the correct information after studying the blcok diagram and that is what you shoud to do to get the real picture.  The XLR input and the line inputs (combo) on the UR22 are basically the same.  You are NOT avoiding the Mic Pre when feeding signals into the so called line inputs on the UR22.
 
Both the Mic and Line inputs still run through the Mic Pre on the UR22.  On the UR22 the Mic Pre is not disconnected as it is on some other interfaces.  It is better to bypass the Mic Pre with a line input and feed any line level input signals further down the line but this does not happen with the UR22.  They simply attenuate the signal and alter the input impedance.
 
The is not so bad as the Mic Pre will be using much less gain (and hence less noise as well) with the line level input signal and it should not alter the sound too much in the process.
 
So you need a balanced XLR to TRS cable to get the signal in. This cable represents no form of impedance matching or conversion.  It is simply a cable that connects XLR to TRS signals. The output impedance of the Valve Pre is low (50 ohms) and the input impedance of the UR22 is high (well 20 K anyway) so there will be no impedance mismatch in this case and no signal loss anyway.  The Valve Pre may introduce a little more noise if anything in the process.
 
Do not use any form of adaptors as you are introducing a transformer into the equation and it wont be a great one at that price anyway.  (Unless you like what the sound of the adaptor does but it is not necessary) At line levels some transformers saturate early and can distort the signal in an unpleasant way. They work better at Mic levels which is what they are meant to do.
 
You are probably better off running your Mic signals direct to the UR22 unless of course the sound of the Presonus Valve Pre V2 is really offering something that you want of course.  There are plugins out there that can emulate the sound a valve Pre as well you know. 

Not at a computer here, but the manual for the UR22 says it switches modes depending on the connector used, so there is a switch internal to the UR22 (I assumed was identical wiring at first as well).

What I did not verify is the 1/4" plug in the center of that UR22 combo jack. I am not sure if it accepts a balanced TRS or is simply a TS connection inside?

*If* (massive if) that jack is a TS, there is nothing to be gained from an XLR->TRS adapter over using a instrument cable from the pre-amp unbalanced to the UR22. If someone could verify that it would be most appreciated.

The clarification on the impedance matcher above are spot on (and not applicable).

Edit: Just saw Jeff's post above, thank you!

You could use an unbalanced lead from the unbalanced out on the Valve Pre to the combo input as well.  But you will loose 6 dB of level in the process meaning that you will have to add a little bit of extra gain on the UR22 to make it up.  I would be inclined to use the balanced lead from the valve Pre to the UR22 because it will give the extra signal level hence making you turn the UR22 gain down a little further.
 
Mic Pres apply less of their sound and less noise when you are using less gain with higher level signals going in.
 
All the happens when you use the centre combo inputs on the UR22 is that the signal is forced through an attentuator (passive) which offers the 20K impedance and drops the level down so the Mic Pre won't overload. It does not really change its mode as such but rather forces the signal through a different path before going into the Mic Pre.
 
The Mic Pre is never bypassed.  This is common on cheaper interfaces.  What should happen is line inputs should bypass the Mic Pre completely and they do on the better units.