How do the Electro Harmonix 6sn7's sound?

I've not heard any, but a friend whose ears I trust says they're somewhat edgy and not very musical sounding. What he says leads me to believe that they sound about as unattractive as the Sovtek 'N7s--thin and edgy, exactly the opposite of the sound I like.

BTW both of us love the sound, overall, of the Ken-Rad copper-post-hollow-filament-tube blackplates, staggered or not--slightly warmly balanced, NOT edgy in the treble, and very musical and attractive. He LOVES the sound of the similarly warmly balanced (and expensive) Brimars, altho they're a little edgy in the treble for me. I find the black-T-angleplates by Tung-Sol and Sylvania to be slightly thin and edgy. RCA black-ladderplates seem to do nothing right and are just boring.

I stumbled into 1 Raytheon-branded Tung-Sol roundplate but haven't listened carefully to it, as I'm looking for a mate for it. They're VERY expensive (as in over $100 each if they test strong), and I may sell the single.

Have you seen this rather-comprehensive thread on 'N7s? http://www4.head-fi.org/forums/showthread.php?t=119638
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"...the older, good sounding vintage tubes are relatively expensive, i.e., a tung sol (sic) round plate for 125.00+...". Indeed, but your example is the MOST-expensive 'N7* I'm aware of. And going to the EH could be viewed as moving from the best to the worst (or close to it; I think the Sovteks are the worst-sounding 'N7).

So what did your preamp cost? What do you have invested in your system. Do you enjoy listening to it? (I sure enjoy mine.) How long does the great sound from a pair of tubes last? If the RP TSs are a little rich for you, try the Ken-Rads. Seems to me there are enough alternatives out there to please you woithout spending $125 per 'N7.

On building tubes, it's not just the physical architecture. Apparently, tube manufacturers had secret formulas for materials, etc., and even those varied from one tubemeister to another, and I think that's one reason why one tube's sonics varied over the eras--another tubemeister was building them.
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* I've stumbled into ONE TS RP, and it tests very well and operates well, but I've not listened carefully to it (without a mate). Probably I'll sell it.
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