JINGERL 2PC GE5670W Tube Valve Vacuum Electronic Tube Upgrade 6H3N 396A 2C51 5670 Pre Amplifier Pairing

Used in a DOUK H2 with a T8 EQ and Beyer 990, awesome sound. Details I only have heard in a MM cartridge from vinyl are now audible from an iPhone using a XLR output. Tubes are still the way to go for my listening preference. The 5670 required virtually no EQ adjustments, whereas the tubes that came with the H2 required a great deal of EQ. Possibly a better match for the 990's, than the stock tubes? I really don't care since the sound suits me as currently configured.

Before getting the tubes, I asked the seller why if the product was made in the usa was being shipped out of China. Didn't get any response. Received the product, two GE5670W and absolutely no sound at all. Totally dead. The good thing is that the seller responded immediately and got refunded with no hesitation, but I would have preferred a refund plus an explanation or any indication of what can be wrong with the product and a response to my inquiry about the country of origin