advice- DACs with Tubes, Or??? budget

Not sure if I should put this in the digital or analog section.... but am looking for a DAC with a tube or a DAC and a tube to put in front of my Emotiva self powered bookshelf speakers & could use some advice. The amps inside each speaker are 50 watts- the manual lists both high and low frequency amps- but I'm not sure if it's a pair in each or just one amp in each speaker. I haven't got a DAC for them yet- but they sound a little bright and fatiguing to me. I am looking at the Jolida Glass FX Tube DAC 3  @ around $500. I can probably get one used for around $300. I also saw something called a "Little Dot" and several Chinese combos. I saw mentioned Musical Paradise DAC MP-D1 @ around $400.

Does anyone have experience with these or others? Or would it be better to buy a DAC and Tube preamp separately? Is there such a thing as a Tube filter that does not amplify sound that could go before the speakers?

I may end up selling the speakers if they are still fatiguing after all this, but I do like the sound of tubes and would like to try them.

Can you tell us the model Emotiva you are using?
Also, what is you current set up? 
Off the cuff, I think your amp would be most directly responsible for the fatiguing brightness, but I could be wrong.

Look at tube buffers
Thanks both of you,

& Nevermind!

Today I decided I am getting Audiodyne speakers and will be selling the Emotivas. I just like a much warmer sound...
i just realised these are active speakers.  My suggestion wont work.

Why not just try tone controls?  You could dobit purely in the digital domain with a minidsp
If looking at the Jolida, be careful what you are driving with it, as it has a very high output impedance of 3kohm.
They don't advertise this, but I got a customer of mine who owns one to email and ask them.
Cheers George