“This version of the 680 sports the old cursive lettering and normal/PA
switch. Apparently the PA switch position changes the impedance so it
doesn’t load down the guitar signal or overload the circuit as easily.
On normal there is a volume drop but PA not so much. The switch is not
on the newer models perhaps because the volume drop was corrected with
circuit upgrades (I am only speculating).”
“It has two separate outputs (local and remote) with completely separate
mix knobs. You can dial in one amp 100% dry, the other 100% wet, one
75% wet, the other 75% dry and so on. The repeats are very dirty and
the oscillation is crazy as these early versions contained the Reticon R5101 (may not be considered a BBD IC, anyone know for sure?).”
