i've decided it's been a while since i'e built an amp so i've dusted off a few bits and bobs, bought new caps, resistors, wire, tubes etc and built me a new one. I have used the schematics for a 5f2a and the mid 2000s gibson Ga5 reissue, so cathode and anode values on the preamp are ga5, its an el84 output like the ga5, tone control and power section a la 5f2 with the 4th electrolytic cap, only minor changes i made really were a 220 el84 reistor instead of 270 and an additional 25/25 cap on the second preamp triode. the schematic for the ga5 came with voltages and i pretty much match those bang on. i've checked all my connections, every wire has space and everything is grounded separately, i've double and triple checked against the schematics, i've near enough wired and rewired the whole thing over the last few days. I can get sound out of the amp with the volume at around 0.5 to 1, after that huge buzzing kicks in and i cannot work out why for the life of me. i thought it might be a grounding issue but i've tried several different things and rewired with no effect. this is the gibson Ga5 schematic http://www.blueguitar.org/new/schem/misc_amp/gibson_ga5_schem.pdf i'm sure you're all familiar with a 5f2a will post pics in a sec...you can probably tell that i've been going over everything a few times and getting a bit frustrated with it...gonna put that soldering iron down for a bit now... any thoughts/ advice/ help really appreciated.