Inexpensive Tube Amps


Anyone have any experience with the following?  I want to try one just to see how the sound compares to my Yamaha and Denon solid states.  Since the Denon is living on borrowed time I will likely have to replace it this year anyway.  Looking at the Nubsound and noted a Germtune that is identical to the Nubsound but costs a bit more.  Reviews are largely good including those on other forums.

https://www.amazon.com/dp/B00NWISSGU/?coliid=I2VYW63Z6R35ZH&colid=3O2PB0XPYIL0T&psc=0&re...

https://www.amazon.com/Nobsound-Amplifier-Single-Ended-Handcrafted-Headphone/dp/B073ZXZ3Z5/ref=pd_sb...

https://www.amazon.com/dp/B00DRUY6EG/?coliid=I1EPHIQ7T6OOPR&colid=3O2PB0XPYIL0T&psc=0&re...
will62
If YOU are referring to me, I know this is a different OP. Just informing him that I would not trust a cheap Chinese amp in the long run.
You get what you pay for.
As noted, many of those economical tube amps from Amazon are made in China. Not a bad thing, but I agree with @lowrider57 : 
the Yaquin is a cut above, also the Cayin's are very good. word has it their integrateds are based on the classic McIntosh designs.

You also have the option of a "DIY" tube kit. but Again, I would not buy indiscriminately on Amazon, but go to an audiophile site that sells them, like Bottlerocket or others out there now that are on their 3rd, 4rth, 5th, design iteration and getting better all the time. 

But as will all things audio: depends on your budget.
But if I were you, I would look for a used Cayin or Yaquin. You pay less, and if it doesn't work out, you can sell it on the used market for the same price you paid and you dont lose money.
I had a Bada for a while, a Chinese hybrid tube headphone amp, drive the bejesus out of my Sennheiser 600s, hence the hybrid. Dunno if they are still around, maybe.
The lowest I would ever recommend for a tube amplifier would be Yaqin as mentioned above.  Any less and you are seriously gambling your money.  I'd also stay away from older Jolida units as they have issues with the PCB boards - I've been down that road with a SJ302a and it wasn't fun or cheap.  Shuguang also had some decent amps but I'm not sure you'd find any at a 'budget' price.

If you wanted to get a feel for what tubes were and not worry about the hassle, I'd recommend checking out the Dayens Ampino solid state integrated.  Its got that tube sound to it and would be a safe bet to see if you want to jump down that rabbit hole.  When I got this in, my Shuguang 845 monoblocks set to the side for several months while I enjoyed the Ampino.