Douk Audio. Any experience with any of their products?

I've seen several products under this name on eBay in recent history, including a tube preamp board that looks pretty impressive. Especially for the money.   They reference a pretty exotic Audionote preamp in the title.  

Douk Kondo Audionote

I noticed the url on the board, and decided to find out more. Turns out the entire website is blank. Assuming this was an error, I messaged the seller.

I was interested in learning more about the Kondo board, and tried the website to see what info was there, and I get a blank page. Just fyi."

I thought they might appreciate the heads up about the error. Instead, I received this response:
"Hi dear customer
wish you have a nice day
the amp board designed by our designers
so you cant find it
best regards
Douk-Amy :)"

Not exactly a confidence builder. I'd be interested to hear if anyone has had direct experience with these folks.
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This is the one I’m interested in; it uses 6J1 tubes. The ad only mentions “passive amplification” in the expanded Product Details — NOT the product description:

Look at this on eBay
HiFi Tube Phono Stage MC Turntable Preamplifier Mini Class A Single-ended Preamp

I suspect that it’s not passive at all, and the writer at Douk Audio got things mixed up.

it does seem awfully cheap for a MC preamp, but they explicitly say “for MC only”, so it appears to be a good bargain.
Ok, this is a different model than I thought you were talking about.  This is clearly an active preamp, and does indeed have vacuum tubes.  And yes, it is not passive.  They would do well to get someone with stronger language skills to write these up.  

It might be ok, but one thing I do know.  The vast majority of the finest tube preamps and amplifiers operate on very high voltages.  This is one of the aspects of tube audio that makes it what it is.  This one however only has an 18V power supply.  It is cheap though.  MC preamps are usually in the hundreds if not thousands.