On my M180s I was using an RCA 5751 and RCA clear tops in the 12AU7 position. That combination worked great with my monitor speakers. I later went to larger, 3-way speakers and it didn't sound good. I replaced the 5751 with a Telefunken 12AX7 ribbed plate and the improvment in dynamics was incredibly better. I subsequently put Telefunken ribbed plates in the 12AU7 positions and the clarity of the system has been greatly improved.
When I originally went with the 5751's I chose them over a Telefunken 12AX7 smooth plate. With the monitor speakers I had at the time I liked the 5751 better, but with the change in my system the all Telefunken set is working really well. That's just my experience with my system.
When I originally went with the 5751's I chose them over a Telefunken 12AX7 smooth plate. With the monitor speakers I had at the time I liked the 5751 better, but with the change in my system the all Telefunken set is working really well. That's just my experience with my system.