Had a Fender Super Champ XD in this week. Extensively butchered by a TV repairman - possibly the worst work I've seen in the past three years. But the bodges caused me to look at the circuit in more detail.

One thing that struck me as being really nicely done is how the main amp controls work; The pots all have DC on them and the wiper voltages are sampled by a cmos multiplexer. Very simple, and really quite elegant and cause for a moment of contemplation.

Sometimes there's a beauty in electronics that we overlook.