Best 12AU7 Type Tubes for a Preamp

Just 3 days ago I got a package from Brent Jesse. It contained the 1960s Mazda ladder plates 12AU7 for my Backert Labs Rhumba. I installed them and kept the preamp ON for 2 hours and sat down for a serious auditioning. I am not going to say "blow out of water" or "I was blown away", etc etc, lest I jinx them. All I will say is that comparing the Mazdas to the Psvane ART series tubes is like comparing a 23 year old man/woman with a 40+ man/woman respectively. Hope you get it. I was told that they need at least 48 hours to sound nice. They sound nice right now. I am not going to keep them ON for a long time just to let them "burn in".

Yes, the Mazdas are pricey, but they are keepers. Mind you, the Psvane ART series are not bad at all. In fact of all the current production tubes, they are THE BEST. Only after listening to the Mazdas, did I realize that the Psvanes produce excess bass that is a bit bloated. The Mazda bass is very tight. Also the Psvanes do not extend and light up the treble the way the Mazda does.

Excellent thread. About two weeks ago decided to shuffle the pre amp tube line up on my Raven Nighthawk/Blackhawk modified, and pure magic was the result. (User experiences may vary) Front row went Volvo/Mullard 3 hole ECC81 (12AT7 equivalent), , row two CBS Hytron 12AU7( USA) , and row three Tungsram ECC82 (12AU7 equivalent) (Austrian).. This is more revealing than any combo tried yet. Tried all low gain 12AU7's throughout but lost details. Kicked the RCA clear tops out of the line up. Blurry (May have been an off pair.) For customers of Raven Audio, Dave and James are tube heads and provide personal help and tubes for their devotees. Very nice , tested, graded, and guaranteed High frequencies now are dreamy.

if this will help

british    mullards- warm, detailed, good dynamics

german   telefunken, siemens, open, airy, good head room, great sound top to bottom

holland   amperex, phillps good sound staging, 3 dimensional, good top end, bass may be a little sloppy with some. ( bugle boys are my favorite)

tung sol, rca , slyvania, electric harmonics or any of the us made tubes are all about the same to me and lower cost.  depends on your listening taste

talk with andy at vintage tube svcs in mich  616 454 3467 very knowledgable and helpful.   tell him damon from atlanta sent you....

Best combo i’ve tried yet on my Jadis amp is a mix of RCA Black Plates and Telefunken Smooth Plates.

I yet have to try Amperex and Siemens Nickel Plates.