i took my amp to a tech this arvo, and im getting the bias mod done and getting it retubed, he mentioned that he could put a master volume on, would this be good? he seems like he knows what hes doing, coz the 6505 doesnt have a master would it work if he put one in and would it make my sound different?
No, it will simply give you more control over your volume.
Yeah, it'll mean that you can even out the clean channel and gain channel without having to mess around for ages getting back.
yea id say go for it