Sweetest sounding 12AU7?

David:

Sweet/warm 12au7 types in my preamp and as an input tube in one of my power amps are:

RCA/Sylvania/GE USA tubes from the 50's/60's (THIS DOES NOT include RCA "clear top side getter" tubes, which I do not consider to be sweet/warm). I also use 5814a's, same brands/vintages as above.

Never used a Euro 12au7 type that I consider sweet/warm with the exception of a handfull of Mullard 12au7 types (have most common Euro Telefunken/Amperex/Siemens versions).

However, you might go broke trying to find a decent warm/sweet Mullard pair, IMO, as their sound/quality for this particular tube type is all over the map (different versions/vintages/productions).

The good news is that the USA versions I mention are common/cheap.

If your Sylvania's have yellow print, then they might be just the ticket (later versions have green print).

Not knocking the Euro types (just don't find them warm) as I do use them when running a Grado phono cartridge as an offset.

Whatever you do don't waste your money on the mid 80's Mullard military 12au7 versions which have flooded the market (the leanest/meanest 12au7 type that I've experienced).

Hi David:

I've never tried the later Sylvania's (Green). I have used Green 6922/6dj8's which were pretty good though (they were specialy screened/selected).

You might ask Rogue about using 5814, 6189 and possibly 5963 tubes. The 5963 tolerates less plate voltage than a 12au7, so it's not a direct sub in all circuits.

I'm also curious about Tungstram Ecc82's, but stopped buying tubes quite some time ago. They used to be listed @ ATSI Tube.

Maybe try a "Rogue 12au7" search @ AA? I prefer to research tubes as they are used in my paricular gear.