[Say]

I recently purchased a Vincent Audio SP331 MK amplifier and have been on a tube rolling fix as of late. First off, the amplifier is doing yeoman work in my main system (my Wolcott monos and Golden Tube SE40 need some repair and are, hence, sitting idle for now). Being a hifi fanatic I delved into the nether world of tube rolling once again. The only tube that is instantly removable in the Vincent is a single 12au7 as part of the power supply (2 of the 6N16 input stage tubes are soldered in place), abetted by 12 transistors for output.

Tubes in play: Mazda/Cifte 12au7, Sino 12au7 (at least that is what I think came with the amp), and Gold Lion ECC82 / B749 re-issue.

Subjective ranking:

-the Mazda (1962 vintage) is top to bottom coherent. Meaning it is pretty balanced all around the spectrum. No particular frequency sticks out. Yet, I still want more magic.
-the Gold Lion is more detailed, by a hair but also has that glassy midrange sound that is too obvious in my system. Otherwise some may find it a good sound for a darker amalgam of components.
-Chinese stock tube that came with the amp. This baby is lackluster in the higher frequencies, however, I'll be darned if it doesn't have that midrange bloom, tube magic thing going on in spades. Plus, bass thunder. The grip of Thor on his hammer. Not tight, just strong! With dynamic energy that can startle.

I need to add that the New Old Stocks are quiet as expected. The Sino too but a tad less so. Placed a Midas tube damper on it for good measure to cut down on any semblance of unwelcome microphonics.

PS - more testing to come. Ordered cryo treated Mullard CV4003 and Radiotechnique 12AU7 / 6189 for good measure this week. Can't wait to hear those babies purr.

[ltr317]

I recently purchased a Vincent Audio SP331 MK amplifier and have been on a tube rolling fix as of late. First off, the amplifier is doing yeoman work in my main system (my Wolcott monos and Golden Tube SE40 need some repair and are, hence, sitting idle for now). Being a hifi fanatic I delved into the nether world of tube rolling once again. The only tube that is instantly removable in the Vincent is a single 12au7 as part of the power supply (2 of the 6N16 input stage tubes are soldered in place), abetted by 12 transistors for output.

Tubes in play: Mazda/Cifte 12au7, Sino 12au7 (at least that is what I think came with the amp), and Gold Lion ECC82 / B749 re-issue.

Subjective ranking:

-the Mazda (1962 vintage) is top to bottom coherent. Meaning it is pretty balanced all around the spectrum. No particular frequency sticks out. Yet, I still want more magic.
-the Gold Lion is more detailed, by a hair but also has that glassy midrange sound that is too obvious in my system. Otherwise some may find it a good sound for a darker amalgam of components.
-Chinese stock tube that came with the amp. This baby is lackluster in the higher frequencies, however, I'll be darned if it doesn't have that midrange bloom, tube magic thing going on in spades. Plus, bass thunder. The grip of Thor on his hammer. Not tight, just strong! With dynamic energy that can startle.

I need to add that the New Old Stocks are quiet as expected. The Sino too but a tad less so. Placed a Midas tube damper on it for good measure to cut down on any semblance of unwelcome microphonics.

PS - more testing to come. Ordered cryo treated Mullard CV4003 and Radiotechnique 12AU7 / 6189 for good measure this week. Can't wait to hear those babies purr.

The Mazda and Radiotechnique are basically the same tube. 

[Say]

Thanks for the response. Yes, I believe they were both made by a Phillips factory in France. Granted they probably sound the same without any treatments but I have been wondering what the Radio Technique sounds like after it has been cryo'd.

[Tyson]

Siemens e82cc is probably the best NOS tube outside of a Telefunken, in my experience.  Not spectacular in any specific area, but exceedingly good in all areas.

[Ericus Rex]

I just sold my pair of RT 5814s and the buyer says they are the finest 12AU7 type he's had in his sys.  He said they were much better the the Telefunken and Mullard 12AU7s he also has.  The problem is finding another pair.  They are apparently very rare.  Good luck!

[bunky]

The Siemens are very good,Amperex Holland Longplate D getter 12AU7's are also very good. the Amperex Holland 7316 PQ longplate D getter is about as good as it gets