Here's a really cool amp .It was made by the Norlin Corporation that owned Gibson the 1970s and 80s. The circuitry was designed at least in part by Bob Moog. They have become known for their fantastic sound, response and versatility. If you Google them you'll see they were used by artists like BB King. It is completely functional, no issues. The Reverb and compressor work.  It sounds great and can do a variety of styles well.