Do whatever you want, Im just trying to save you from wasting your time and money.
Anyway all suggestions are welcomed, it is so nice chat with another people and know new ideas :thumb:
But seriously, the problem with TLA gear is so fundamental that changing the componants youre talking about wont make them sound any better
As fas as I experienced changing some components become in a better or worst results. Think that I´m becoming from guitar amps world. I just work with that kind of equipment when thd distorsion are welcome as much you can :grin:
I work on several Marshall and they had ever the same solution, you must to replace the nasty tubes with svetlana, eh or jj and replace the op amps with opa2134, that results in a completely new amp, more balanced with a cleaner tone....
The main problem is the transistor output stage they use. If you could jump over this and use even a good sounding opamp like a OPA2604 or 5532 you might get some nice sound out of it.
The PA1 doesn´t have any transistor output stage, at last they doesn´t appear on the schematics that provided me tl. The only transistors that appears on the audio path are on the tube triodes plate, with a classical configuration of push-pull. That transistors seems to be for a negative feedback to lower the gain, the thd and increase the bandwith, maybe I must to do a more exhaustiv study about that circuit, but in one minute seeing are the first ideas that occurs to me.
All the output stage is implemented with op amps, concretely the ne5532, that op amps sounds great but I prefer the opa2134, ( maybe am I a sybarit??? :? ) so I decided to replace some 5532 with 2134 and leave some 5532 without no changes, for example I replace all the 5532 with 2134 but I leave the 5532 on the ultimate amplification stage where it is done the balanced signal. I always like that sound on balanced signals :grin: