Preamps better than Parasound JC-2 ?

@milpai 

I’ve owned a lot of tube gear. When a tube gets “weak” on the way to failing, it gets a bit more white noise rush and lower output. I usually replace the suspect tube(s) when I detect it. It’s pretty discernible during causal listening. No overt system crashes or other collateral damage. 

@glennewdick 
Audible Illusions products include circuits that run tubes ragged. Plan on replacing those tubes in their products much more frequently than tubes of other products.  

So, I researched a few tube preamps and I would like to have one with XLR in/out. One such preamp is the Backert  Labs Rhumba 1.2. But I believe tubes have their own issues - like hum.
http://forums.stevehoffman.tv/threads/review-backert-labs-rhumba-1-2-preamplifier.732674/
One reason I like this tube preamp is, it has a top cover to change tubes. I looked at other like BAT, and they don't have covers like this one. One thing I don't know - can you keep the preamp "on" 24X7? Or will that kill the tubes?
Another point to note with tube amps is that their output impedance is always higher than a SS preamp.

@milpai 

Hum is not an issue of tube preamps any more than it is solid state. Hum can be caused by a variety of issues- ground loops amongst them, but I suspect its not that in this particular case.
There's no point in keeping a tube preamp on all the time like solid state. They should get to where they are going in 2-3 hours, unlike solid state which might take a week of on time.

In the case of the Rhumba, its output is actually single ended- its XLR connection is there for convenience only (this can be seen in the interior photos). This is why this unit hummed in the review you linked- the XLR cable the guy was using was picking up noise because it was running single-ended!

We make tube preamps with XLR inputs and outputs, and they are in fact actually fully differential and balanced all the way through- and (like the Rhumba) one stage of gain in the line section and zero feedback, and with a low enough output impedance to drive any amp made. So there are alternatives- BAT would be another.
Even if you were to go single-ended though, I still think you will find that the tube preamps have an advantage.

Here is something to chew on. I own a Schiit Freya preamp. It has 3 ways to listen to it. It also has balanced inputs and outputs. 1:) Passive Mode (a straight thru listen) just a volume control 2:) JFET Mode a nice solid state preamp presentation with extra gain 3:) TUBE Mode 4 6SN7 tubes
Anyway.... this is only $699 direct from factory. And I tell you that it is wonderful to be able to press a button on a remote and change to a different type of sound presentation. I listen the tube section quite a bit. But that doesn’t stop me from listening to the same song running Passive Mode or JFET Mode.

The only miscue with the preamp is the volume control emits clicks when adjusting the sound. The Freya uses a 128-Step Relay Attenuator that allows for great sound at low volumes. Many volume controls do not do so well with low volume control, and the stereo separation is not at the same volume.

If you want to hear what your system sounds like "Six ways from Sunday", it is worth a gander at the Freya. I have the Freya in a system that is very expensive. So don’t let the cheap price make you think that it doesn’t compete with the big guys. If you don’t like it, resale value is extremely good for Schiit products. You would have to go with much more money to get anything close to being better.