In my MA2275's preamp section I replaced the 12AT7 Drivers with NOS Mullard CV4024's, Re-issue Mullard 12AX7's for the tone control preamp tubes(the tone controls are defeated and thus out of the circuit most of the time) and Sovetek 12AX7LPS in the Phono Preamp section. Great tone and low noise also you are are spending about 1/5 of the cost of Telefunkens and Amperex and most likely have a quieter Phono section.