Tried the Sylvania’s today, maybe for an hour or more, Used the Tubesox to make it a fair comparison.
The Sylvanias are a nice tube, very smooth with nice extended highs. The midrange is a little shouty compared to the JAN GEs.
But is is in the bass that things did not go well at all. The thunderous floor shaking bass was gone. Like moving from a ful range floor stander to a good bookshelf speaker. Tried to give it time to break-in, but I got fed up and reinstated the JAN GEs.
I think In my setup the JAN GEs are a much better match.
I’ve been told that equipment supports are very important and that damping vibrations under the equipment was a must.
I tried some compressed rubber pads (designed for washing machines) under the M1200s. Did not last more than 2 minutes. The vibration pads robbed the bass of all the foundations. Good bye thunderous rolling bass, hello aneamic bass.
The chap who suggested I use the vibration pads has a good set of ears, but of late I am finding myself saying just no, that is not right.
Have a Happy Merry Christmas and stay safe in the depths of deep winter, especially in the USA. Being summer down under, it is a matter of enjoying longs hours of sunshine and lots of soon the be very hot weather.