What is spring reverb?
that is a few springs inside the amp that is in a circut wich, when used, sounds like you are in a huge room because the sound echos a little. by the way the pathfinder 15 is a great amp.
customisbetter is correct. there are actual springs making noise in your amp.
Damn, all this time I thought it was a reverb that wouldn't work in the summer, fall and winter.