So my Audio Research VT100MKII is stuck on! Switch rocks on and off but the amp stays on.Contacts are probably welded shut. The inrush current for that amp could very well be over 50 to 75 amps. It is important when operating the switch ON and OFF to always move the switch in a fast quick motion.
Now this morning I plugged it in to check it, the outlet sparked and the amp blew its fuse.Don’t do that. You would have to insert the plug into the outlet receptacle is a fast, quick, motion as to prevent arcing and the interruption of high inrush current needed to charge the caps in the power supply. Hopefully all you did was cause the line fuse to blow. I hope the fuse was the OEM fuse for the amp and not an aftermarket one.
Is there a fix without having to send back to ARC again?!!Yes, order a new switch from ARC and install it yourself. You do need to have some mechanical and soldering skills. If you do not feel confident with doing it yourself find a local tech in your area to do it for you.
Scroll down to the bottom of the page and click onto right hand wiring diagram. You will see the power switch in the lower left hand side of the drawing.
http://www.arcdb.ws/VT100/VT100.html
Note the switch is a double pole single throw switch. The main power for the amp goes through the contacts on the left. Just a guess the other set of contacts may have still been functioning ok. I doubt if you remember if the switch was in the off or the on position when you tried plugging the amp in this morning. Hopefully you did not cause any other other damage, besides the blown fuse.
Jim