Making a whole amp into a poweramp? What needs doing?

[murraymurray]

Hey this is for the more technically inclined dudes
I just picked up a soldano SP77 preamp and was thinking rather than splashin out for a rack poweramp i could possibly turn an amp i have already into one.
Firstly, i dont have an amp with an effects loop, so thats the first issue.
I have an old 100w Holden (NZ made amp from 60s/70s) that runs KT88s
Was thinking i could get someone to modify it so it basically skipped the preamp and went straight to the poweramp, the techs around here are hard to talk to about things so though i should investigate what actually needs to be done.
Would the input go directly to infront of the phase inverter? or does it need part of the drive stage involved still as well?
Also could there be a problem with the volume position as its not a master volume amp, more like a plexi set up (i think) could a PPIMV fix this, or alternatively rather than skipping the whole preamp just cut the tone stack out of the equation?
or is this just a stupid idea all round?

[HTH AMPS]

You could run it straight into the PI via a pot to act as a master volume, but just try running the SP77 into the Holden's front end first - you might like it that way (I much preferred the Marshall 9001 preamp run like this over direct into a power amp)