some of the great 12au7s i've found are the cbs/hytron 5814wa, rca 5814 triple mica blackplate, rca command 5814a triple mica blackplate,raytheon 5814 blackplates triple mica,brimar 13d5, raytheon 12au7 blackplates.
Recommended 12au7/5814s for Atma-sphere MP-3
I'm told these are the tubes that make the most difference in the MP-3; I have Sylvania 6sn7GTBs for those tubes in the unit. I think that how a tube sounds has a lot to do with the circuit that it is in, so I would like to hear from those that have rolled the 12au7 tubes in this particular unit; although I also welcome general comments on the 12au7/5814 breed. I have RCA Clear Tops, Siemens 5814s, RCA Black Plate 5814s, RFT 12au7, and RT 5814s, and Tungsol 5814s - I haven't started rolling yet; I have the Siemens in the unit and it seems to be very clear and spacious, but I'd like to know what other flavors I can expect with some alternatives. Thank you.