Scrith
500+ Head-Fier
I've found most 7N7's to be quite enjoyable -- Frankie or otherwise. The Frankie does have a bit more extended bottom-end and more sparkle up-top. It exhibits a nice slam in the bass that really punches.
My testing today leads me to agree with you...the non-Frankie 7N7 sounds great, but dropping in a real Frankie reveals the non-Frankie is a bit thinner in the bass area and not quite as exciting. Not bad at all though. The Philco Frankentube I'm comparing it to was about $6 (cheaper than the 7N7-to-6SN7 converter I'm using, LOL).
