I'm wanting to play around with the configuration of the preamp valves in the 64 vibroverb custom... I have JAN Philips 7581A's in the power section and a JAN 5AR4/GZ34 rect. I have at my disposal 2x NOS RCA 12Ax7's (which i use for the vibrato channel) 2 x tung sol 12ax7 reissues, 2 x JJ ECC803's and 2x NOS JAN 5751's I do particularly like the RCA's but what about the other positions? I'm also considering taking out the Valve from V1 and see how that sounds... I crank the amp to about 8 when i play and am not particularly concerned with bringing down the volume... i find it difficult to describe the tone im after but it's somewhere between SRV/Clapton/Hendrix/Ford (who isnt..?) I have a large pedal (see sig for list) What do people recommend... thanks for your help... L.