Rebuilding a SF Fender Super Reverb and right now has the standard 1K and 4.7K resistors for the preamp and PI plate B+: If I wanted to drop the voltage from 270V to ... say down around 230V (it was suggested to me to try using 4.7K in place of the 1K, and 10K for 4.7K) what tonal changes would occur? (Deluxe Reverb is 10K and 10K but is filtered differently) I've heard lower B+ will brown the sound and lower headroom a bit but I also read where it will brighten the tone. Seems like it would soften the sound some? I've read where some techs will drop the V a bit. Thanks for any info!