A very good quality amp and in very good condition, everything worked well as long as the function selector was held in a certain position. Easy enough to diagnose a dirty switch but not that easy to get to for removal. Probably an hour of stripping down and unsoldering and I had the switch on my bench, even that took a bit of stripping down but once apart I could see that the contacts were very tarnished. A few minutes with a cotton bud and some electrical cleaner, and then getting on for another hour to solder the switch into place and reassemble the amp and I had a perfectly operational switch and a great sounding amp.
