[Bekay3]

Last week I got the Vali3. The week before I got a JAN5670 NOS 5-STAR 3 MICA BLACK PLATE VINTAGE TUBE off eBay.
$20 tube + $175 Vali3 (w/ shpg & tax) = happy ears. I am using the device as a preamp in a 2.2 audio system, mostly.
After 72hrs continuous playing, I am starting to hear a fuller, warmer tonality and a wider & deeper sound stage. Lets see if continues to improve over the next few days.

[FullRangeMan]

Last week I got the Vali3. The week before I got a JAN5670 NOS 5-STAR 3 MICA BLACK PLATE VINTAGE TUBE off eBay.
$20 tube + $175 Vali3 (w/ shpg & tax) = happy ears. I am using the device as a preamp in a 2.2 audio system, mostly.
After 72hrs continuous playing, I am starting to hear a fuller, warmer tonality and a wider & deeper sound stage. Lets see if continues to improve over the next few days.

Tube equips cant operate so long due heat or tube failure.

[nlitworld]

That's encouraging to hear good results from that setup. The GE and JAN5670 are nice tubes. I have a few different ones for my MHDT dac and enjoy them. If you really want to take things up a notch, find a WE 396A/2C51. Smooth, extended frequencies, and HUGE atmospheric soundstage. Almost silly to spend nearly as much on a tube as you did on your Vali3, but why not have some fun with it. 

[Opus Flatus]

I also just picked up a Vali3 and a Modi; a short Schiit stack for the office. I am very impressed with this combo: dead quiet with the stock tube. The sound is clean, detailed, neutral, and not overly euphonic. The sound stage is good but not the largest or deepest I have heard. For a budget product, it is excellent. Rolling some NOS tubes will most probably open up the sound stage. I will have to try a GE 5670 soon.
I was using a Khadas Tone Pro and this Schiit stack is much better.

Headphones: Drop Fostex T-XO and Etymotic ERX