IDK bout cleartop. I use mine to tone down bass a bit but i dunno tubes make my head spin lol. Buying locally is real cool. I try to hit hamfests every chance I get, which isn't as often as I like. Maybe they have those where you are. Best advice is to buy as many as you can and listen and decide for yourself, that's half the fun. Take a look at cbs hytron also. @chinook9 gave excellent description a few posts ago.
And not all rca's sound the same, E88cc rca are all rebrands/oem. Greyplates sound waaay diff then blackplates. Greys are airy with nice mids and highs and complementary bass. Blackplates are aggressive on the low end, great impact and extension, with luscious mids and complimentary highs. Cleartops are a whole other animal. I like them all but they are VERY diff, just my opinion.
I've read numerous books and on internet about tubes and circuits till my head almost exploded. The sunrise/horizon uses the IRL 510 mosfet, which extends into the 30,000khz freq range. My bravo came stock with IRF630 mosfets which roll off at 10,000khz i think. Maybe you'd fare better with a swap of mosfets but I'd hate to mess with perfection :)\
12at7 draws less current than 12au7. 12ax7 draws most i think, plenty of info on net but they don't sound same IMO
Edited by stupidmop - 4/21/13 at 7:10am