MA 25 possible problem
Sat, 04/28/2018 - 10:42
I recently bought an MA25 and not knowing, plugged it in and turned it on without it being connected to a speaker. As soon as I flipped the power switch there was a spark from that switch. I immediately unplugged it. Someone told me that could fry the transformers. is there any way to test what damage, if any, has been done. Are there fuses etc i should check. I know very little about electronics clearly. It's very possible that i had the rectifier tube in it's socket incorrectly because the rectifier tube trhat came with it was for some reason missing that little plastic bulge that assists in locating where the pins go correctly
thanks
Hello Doug- Thanks for writing. Well, oh boy! Where do I start?
Yes, you should never turn a tube amp on without having a speaker connected, but I doubt very much that it caused your problem.
The "index pin" in the center of an an octal tube (like a 6L6, 6V6, or 5U4) is frequently broken, but it does not mean the tube is bad. Of course, with a broken index pin the tube can go into the socket several ways and believe me, there is only ONE way a tube should go in. You have to look at the remains of the pin to determine the proper position of the tube in the socket.
If you found a 1940's car in a barn and it wouldn't start, what would the problem be? If you didn't know much about cars, what are the odds that you could figure out why the car won't start? Think of all the possible reasons! Firing up a Masco MA-25 that has probably never been serviced in 50 years is a similar situation. There are just too many possible reasons for the amp not working.