[Harp-L] repairing a Roland Bolt 60 tube amp for harp use

[Kevin M Brown <kevin.brown@xxxxxxxxxxxxx>]

hi

my old (cica 1980) Roland Bolt 60 (valve power amp, solid state
pre-amp) has not been used for very many years. [i have been using a
fender bassman 100 head but as I don't play much now it's really too
big (with the speaker box) and heavy to have around so i sold it].

Enter the Bolt which re-emerged from the depths of the garage and
promptly refused to power up (it's probably feeling v. neglected). I'm  
about to take it to an amp technician to fix it up.

i'be heard talk over the years about modifying guitar valve amps for
harp use by replacing the tubes with ones more conducive to having a
fatter sound. But's that all I know about it and I'm not at all a  
technical person when it comes to electrics/electronics.

My question to you is: whatever happens when the amp guys look at it,  
i expect the tubes to need to be replaced after all this time so would  
it be worth trying to get the amp guys to replace the current tubes  
with more "harp friendly" ones?  OR, is this not worth it/ not possible?
of course i can ask the amp guys but i figure they won't be
harp players.

if this helps the currently fitted Roland valves are:
Power Amp
  2 X 6L6GC (Tubes)

pic  Phase inverter
  1 x 12AT7  (Tube)

thanks for your time
kevin