telefunken small signal tubes (real ones from back in the day, not the modern branded tele’s) are excellent, though they are in the clear and precise school of sound with excellent air and imaging, not very overty tubey in their sonic nature
to me they are not better than other top european tubes from that era, mazda’s adzam’s siemens cifte’s dutch amperex and even hungarian tungsrams
somehow the tele’s became ’legendary’ and demand for them went off the charts... made them poor values to buy, even in the 80’s and 90’s