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
Having read this thread and being a long time AG user, it seems a great lesson in the fact that there are many paths and many people in this hobby. Threads like tubes vs SS go on forever, but that is what makes it fun. My own personal preferences are for quality used stuff, just like I never buy a new car. But others go differently. For me the fun is in finding a good or even great piece of classic gear and upgrading it. Will it match my friend's Macintosh outfit? Of course not, but I can't afford that so I do the best I can. I think that is what the OP is after. 
Here's an old standby - Jolida. An old used one might be a good inexpensive investment. I've heard them make magic with Thiel 2-ways, low efficiency btw.
http://www.jolida.com/product/fusion-1102
Will, I can't speak directly to those amps you list but I do use one of those Chi-fi cheapies in my bedroom system, which is this one:

https://www.amazon.com/APPJ-mini2013-Original-miniwatt-Amplifier/dp/B00JSNLT28/ref=sr_1_fkmr0_2?s=el...

I might be made by Gemtune also.  It's only 3 watts and I use it with my 101db efficient Zu speakers.  I will say this, in a small room it sounds as good or better as any other amp I have owned, and that includes a few multi-thousand $$ amps.  I've been using it for about 3 years with no problems.  And if it breaks I will probably just buy another one for about $130.  

So if one of those you listed interests you, I say go for it. Only caveat is your speakers.  I did use mine to power some 88db B&W towers for a while.  It worked but the sound was nothing special. You might be ok on your 91db speakers but you'll have to try it and see.

Hi again will62, I have a miniwatt as well (the Tube Cube 7 version).  I can tell you that the Oldchen sounds much, much better, the miniwatt doesn't put out as much bass, even to 98db efficient speakers.  

I hope those AudioKarma discussions helped.  Post in one of those topics, a bunch of us own them and have been talking about them for a long time.  I think you'll get more of the type of feedback you are looking for than you've gotten here.  

Foremost we are dealers, not of the amps you have listed but I have come across them since we service and take trade ins. We have had a very similar Yaqin traded in and I have a few customers who have tried the others you listed. As some have said and I feel it is incredibly true, you get what you pay for. Do these amps sound bad, not at all, for $200-300 they sound like they should at that price. Cannot compare them to a $2000-4000 amp because that is not what they are. Bargain of the century, absolutely not. With that said if your looking for a small inexpensive bookshelf system and want to roll the dice, maybe.

There is so much made in China animosity which for political reasons I can understand along with safety being a concern. We rebuild many 1970s solid state units which the same attitude was there against Japanese built units then. Today many of these are prized pieces for some vintage collectors today, however many of them were junk as well back then and are forgotten.

The one piece of advise I can offer is tube amplifiers tend to sound as good as the transformers they are built with and the quality of parts in the circuit. The iron on all these amps are tiny which I've seen many fail within monthes of buying. With that saving for a better amp makes more sense. Even if Amazon reviews are truthful, they are usually written shortly after purchase. A quality tube amp should last decades, not years which is what I feel you get with these inexpensive amps. 

Good luck with your audio journey!