Gr8Scott
Wookieologist
About a month prior to the Christmas Holiday, my nephew's Mig 50 went silent and he assumed that the power tubes went bad. I bought him a Vintage 30 speaker to complete the set in his 2x12 for Christmas plus a new set of tubes. I haven't been able to get around to helping him get everything straightened out until this weekend.
I decided to put the amp speaker in before moving onward to the tubes. Opened up the cab and unsoldered the pos and neg connections the amp already had for the less marshally speaker. Added the new speaker and soldered it in. Checked the ohm rating to make sure everything is cool and nothing was cool. Infinite ohms (meaning I've got a loose connection somewhere). I re-soldered the speaker and still had infinite ohms. Opened the back that lets me take a peek at the other speaker and found the problem. It's connection had worked it's way loose somehow. Seems the solder had a cold joint and popped loose on me. Re-soldered that connection and tested the ohm rating. Much better at 14 ohms. Buttoned the speaker cab back up then. I was very concerned at this point that the OT might have fried if this connection broke loose when being played. It turns out it did break loose while being played.
Put new tubes in the amp and fired her up. Thankfully she sounded just fine and went as loud as we wanted her to go. Tubes feel really cold to me though and probably need a good biasing to sound their best. The 6L6 short bottles I bought him really have a nice tubey sound to them. Much more fendery than I had anticipated, but still really cool nonetheless. Turned the amp into a blues machine. I visually checked the old tubes and they look fine. The only experience I have with tubes blowing or being bad are some Chinese KT-66's that lost vacuum and a couple of microphonic 6L6 tubes that had to be replaced. I think he lost his speaker connection when playing and the ohms went infinite so to speak. He shut it off quickly enough to avoid any real damage it seems. Smart kid.
Test probe is almost completed for checking bias. I have to solder the pins in and find a way to attach my test probes to the side. :banana:
I decided to put the amp speaker in before moving onward to the tubes. Opened up the cab and unsoldered the pos and neg connections the amp already had for the less marshally speaker. Added the new speaker and soldered it in. Checked the ohm rating to make sure everything is cool and nothing was cool. Infinite ohms (meaning I've got a loose connection somewhere). I re-soldered the speaker and still had infinite ohms. Opened the back that lets me take a peek at the other speaker and found the problem. It's connection had worked it's way loose somehow. Seems the solder had a cold joint and popped loose on me. Re-soldered that connection and tested the ohm rating. Much better at 14 ohms. Buttoned the speaker cab back up then. I was very concerned at this point that the OT might have fried if this connection broke loose when being played. It turns out it did break loose while being played.
Put new tubes in the amp and fired her up. Thankfully she sounded just fine and went as loud as we wanted her to go. Tubes feel really cold to me though and probably need a good biasing to sound their best. The 6L6 short bottles I bought him really have a nice tubey sound to them. Much more fendery than I had anticipated, but still really cool nonetheless. Turned the amp into a blues machine. I visually checked the old tubes and they look fine. The only experience I have with tubes blowing or being bad are some Chinese KT-66's that lost vacuum and a couple of microphonic 6L6 tubes that had to be replaced. I think he lost his speaker connection when playing and the ohms went infinite so to speak. He shut it off quickly enough to avoid any real damage it seems. Smart kid.
Test probe is almost completed for checking bias. I have to solder the pins in and find a way to attach my test probes to the side. :banana:
