You can't wire the output of the Ashly power amp directly into an unbalanced line input. That will likely damage something. Your power amp accepts a line level input and produces an amplified output to drive distributed (transformer-coupled, in your case -- that's what the 70V connection is telling you) loudspeakers in a restaurant or retail store. Your ...
What am I missing?
Use a 24 V lamp instead.
Back of an envelope calculation. The formula I use is P = U * U / R.
Your amplifier: 100w in 4 Ohms --> cirka 20V output.
Put 20 V into a normal 110V / 100W lamp (around 110 Ohms) gives you about 4 W = not enought to light it. Even worse with a 40W lamp (about 320 Ohms) --> about 1.3 W.
The Peavey in the ...