There is the even better, the Alps "Back Beauty", but they cost a lot more.
https://i.ebayimg.com/images/g/O1kAAOSwQolbFS19/s-l300.jpg
https://www.picclickimg.com/00/s/MTA3MVgxNjAw/z/W~QAAOSwYGFUv3Ah/$/1pcs-ALPS-RK40-50KA-Black-Beauty-...
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSrMqGsGmwCWfSPDB1Y9O6LrTsKEfybIOqvEkwLGaCSU4Li...
We just have to wait for someone to have a look at what’s inside them.
Cheers George
https://i.ebayimg.com/images/g/O1kAAOSwQolbFS19/s-l300.jpg
https://www.picclickimg.com/00/s/MTA3MVgxNjAw/z/W~QAAOSwYGFUv3Ah/$/1pcs-ALPS-RK40-50KA-Black-Beauty-...
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSrMqGsGmwCWfSPDB1Y9O6LrTsKEfybIOqvEkwLGaCSU4Li...
I am sorry Georgi, but this device is an EXCELLENT passive unitAs for the sound, I don’t doubt you like it,. and what you get is a bargain, I’m just pointing out the confusion of their ad in what actual value Blue Velvet is used and you get, all values will work as I pointed out, some better than others, because of proper >1:10 impedance matching input and output.
We just have to wait for someone to have a look at what’s inside them.
Cheers George