NAD!

[CTN]

as for the mods and schematics and whatnot....

I looked for that stuff for my TM18. A long time I looked. several years. Couldn't find squat.

Just about every component in these amps is PCB-mounted and it's all surface mount stuff that's crammed into tiny spaces on the board. If you were to take a soldering iron to that and accidentally apply too much heat to one spot, who knows what other damage you might do to neighboring components or conductive traces.

The only mods I ever came across were people talking about swapping tubes.

[Oinkus]

Ext. speaker jack ! Yeah changing tubes voids the warranty too ! from the manual ->>>>>Swapping tubes is more easily, quickly, and safely
done than with a conventional amp. This is a big
help not only in case of a defect, but also when you
want to compare different brands of replacement
tubes.
CAUTION: Replacing tubes is a job for qualified
professionals! TSC™ merely spares the technician the
biasing effort.
What?

[GoldenVulture]

CAUTION: Replacing tubes is a job for qualified
professionals!

[Oinkus]

CTN , you should use a resistance soldering iron for PCB boards.