Not sure how old the Lowther drivers are as I'm the second owner. The company in England has been in business since 1934. These are DIY using Martin King's
mass loaded transmission line design. The wooden cigar boxes on top contain the baffle step correction circuit.
I spend more time listening to the Fire Stick/HDMI audio extractor/DAC combo than I do with the Node and separate DAC streaming Ultra HD. I don't notice any advantage with the latter paired with my Lowther/Bottlehead set up.
With the 4K Fire Stick and HDMI audio extractor you use the remote not your phone. In this picture you can see 192 on the DAC which agrees with the monitor display.
I enjoy both class D and SET amps. Single ended tube amps don't test so well so there's not much discussion here but I love them. I have a 2a3 and EL-84 and waiting on a Decware to be built that I purchased almost 2 years ago.