I’ve been listening for over a week the Elrog ER801a prototypes. I can say that I’m very please with them. Before I make any further impressions about their sound, let me start from the beginning.
I purchased last year from ELROG (now Deutsche Elektronenröhren Manufaktur GmbH.) a pair of these valves to be used on my VT25/10Y preamp. I do not own any 801a, but have a good stash of NOS VT25 and 10Y valves. I love this preamp, probably my favourite with the 01a.
Thomas Mayer offered me to send me a preliminary set of prototype valves in advance so I can submit them to the mercy of my tests. That sounded like really good fun and also I thought that the folks out there would be very keen to see the results.