Valvo and Telefunken 12at7s tubes and other related questions

[pfflam]

What's the story with these?

I would be using them in PI slots for Fenders, all the while coveting the clearest most fidelity driven sound I can get (I have 2 pair of NOS on the way)

also, what about GE 6679s? or any 6679s? are their ruggedness compatible with decent sonic qualities?

[pfflam]

Just thought I'd ask

[Rambergwest]

Excellent tubes, did the seller state the section balance on the tubes? ideally they would be balanced and the ones closest to that state would be my first choice for the PI slot. Brent Jesse has this to say about the tone


TELEFUNKEN, SIEMENS, VALVO, LORENZ, and other German made NOS: These tubes are usually characterized by an impressive open "air" at the top end. The soundstage is large, even in mono applications these tubes have a great 3-D image. The midrange is ruler flat, and the bass is tight and accurate. These tubes have a fine sense of dynamics, and most are impressively quiet. These are not "warm" tubes, and to some ears their lack of midrange warmth may be heard as bright. I tend to think of them as accurate, and their clean, focused sonic image is astonishing. My personal favorites. For critical phono or microphone preamp needs, grab the rare Telefunken or Siemens ECC801S before they are gone! They are absolutely incredible tubes that will never be made again! AMPEREX, PHILIPS, MAZDA and other Holland/France/Belgium made NOS: These tubes are a great balance of a clean, airy top end, nice midrange warmth, and accurate bass. They are very pleasant, clean, and musical to listen to in hi-fi applications. Unlike other clean European tubes, these break-up impressively when overdriven in a guitar amp. The rare longplate versions are the same, but with even more soundstage space and detail. The Mazda adds a nice bit of dynamic punch to the sound.