You can run a search here. There have been many using those for some years, although the brands escape me now. You can search NC500 and NC1200 which are the OEM modules.
FWIW, for my active system I assembled a pair of Hypex UcD400HRx (I think they were HRx...) for my midbasses and very happy with them. Tubes for mids/treble though. I've had them for about 4 years, trouble free, and wouldn't hesitate in buying again from Hypex, nor assembling their DIY modules.
FWIW, for my active system I assembled a pair of Hypex UcD400HRx (I think they were HRx...) for my midbasses and very happy with them. Tubes for mids/treble though. I've had them for about 4 years, trouble free, and wouldn't hesitate in buying again from Hypex, nor assembling their DIY modules.