Douk Audio. Any experience with any of their products?

I purchased a  chinese tube preamp from Douk about 1 yr ago,, he was kind enough to allow me to ship it back to a  china office in California,,I kindly gave hima  $100 restock fee, = all worked out OK. 
So yeah  he is a solid seller,,I know a  friend here on audiogon who had buys from Douk, and no issues, 
= 100% solid. 
Zero complaints,
Amy will respond,, although agree their english could use improvement,,,but then my english ain't all that  polished,,,
I'm from New Orleans,,what do you expect :-))

ese gear manufacturers. Their EAR phono stage clone is really good, as are their tube pre amps

 Not all, but some of his preamp/amps are good value,, But or much superior quality shop chinahifi,,which carries Cayin stuff, which to me iis equal to PL and just below Jadis,, Yes I did say Just below Jadis. Maybe superior to PL in amps/preamps. 

Hi, thought I’d jump in here.
First: I have no connection with Douk Audio.
Second: I’ve been using Tube/valve amps since the about 1987, starting with a pair of Audio Innovations 800 (6b4g) Monoblocs and currently a pair of BottleHead 2A3 Monoblocs.
I bought my first Chinese valve amp in the early 2000’s thinking that it would be a waste of money, when it finally arrived I was very pleased with the sound quality, it was, quickly, followed by a monster 6 channel valve amp for my home theatre system (still have that) over the intervening years I’ve had a number of Chinese amps, pre-amps, CD players and Dacs all of these have provided very good performance apart from a pair of KT88 Monoblocs that were sold to me by someone who knew them to be faulty (eBay).
My current collection includes:
Douk:
Little Bear Ipod amp, being a tube design the battery life is restricting but the sound is good. Tube was rolled by the previous owner.
Little Bear tube based MM phono stage, sounds very good. Haven’t got round to rolling the tubes yet.
EL34 amps:
Reisong A10 straight out of the box it sounded very good, so I bought another, they now run with Chinese 6L6GC tubes and are sounding even better. Point to point wired version with "better" transformers.
Nobsound NS-03d straight out of the box it sounded very good, sounded even better with British MOD Mil spec 6L6g, Raytheon Mil spec 6SN7s and Russian 5U4G. Now kept as a spare.
Nobsound NS-10d similar in design to the NS-03d but without the posh wooden trim and ammeters. Again out of the box it sounded very good and again when equipped with the tubes as above the sound improved.
All of the above are single ended designs, and are the point to point wire versions which are supplied with "upgraded" Psvane EL34b tubes and "upgraded" transformers.
Explained: If you look on the Doukstore site each of the above amps (and many others) is offered at a number of prices/options, the lowest priced option has PCB mounted components and base model tubes, the next price-point gets you the point to point wiring, better transformers and Psvane EL34b’s, spend a bit more and you can get a cage for the tubes.
Would I choose the basic low price option, no I wouldn’t, it would certainly cost more to upgrade one than a simple tube rolling exercise.
In short, over the last 15 or so years I’ve experienced only one (Chinese) amp failure, to be fair it cost £70 new and wasn’t economically viable to repair.
Two "failures" due to a repair tech who promised improvements but delivered the opposite, both pre and power amps that worked very well before he worked his magic.
Just so you know the speakers used to pass judgement- 1970’s Shackman (Dynastatic) hybrids or Gennexa LX5 pro (Linaeum tweeters).

I have a tube singe input pre-amp and a tube buffer unit. Both built like tanks both trouble free for 3 yrs?. I also have 2 Schumann Wave generators both working fine. They are nice people to deal with. They seem to be hit or miss but I have nothing but good things to say about my limited experience with their products.
Hope this helps.HG NYC

Only their springs and I got a refund on the newer version because I felt duped. They were plastic, not aluminum like the originals. I prefer not to deal with China unless I have no choice, like iPhone.