Lite Audio GA-31a phono preamp, is it a clone?

It's an unusual circuit in that the tubes are used in what looks like a cascode configuration with transistors doing the amplification. Are the tubes there to add gain or flavor only? There's also a 47uF electrolytic cap on the single-ended input which is not good.

I would give the stock tubes a chance, before putting costly NOS tubes. Also, there may be just one slot where rolling tubes makes a noticeable difference.

Hello noromance,
I had already noticed this hybrid setup. I hope it is a wit to improve the project, not a defect.
About the 47uF electrolytic cap on the single-ended input, what do you recommend to do? Remove it? Replace it?
Tenx!

@tablejockey  looking at the project diagram, could you tell me which are the most important slots?

I'm not qualified to interpret that schematic, perhaps noromance  or someone else will chime in. 

If anything it's going to be just a pair(L/R), not all 4 that will make a noticeable SQ  difference? You can always just experiment when you get it. You'll be out just two pricey tubes instead of 4.