| Author | Message | ||
     Matt White (mwhite) Username: mwhite Registered: 11-2012 |
I have seen it mentioned a couple of times that the early model tube driver section was modified to solid state in order to avoid an issue that can take out the power section. Does anybody have details about the actual failure scenario? Has anybody come up with an alternative solution using the original circuit? I am in the process of bringing back to life a 65 that has the described symptoms. I am interested in preventing this from reoccurring, if possible. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
I have the actual instructions FROM Musicman on the step by step to install the SS driver board if you're interested. Personally, I wouldn't. I don't like the SS driver amps as well but hey, that's just me. It involves changing the amp around to a cathode driven power stage and it's not for the faint at heart. You are changing the whole personality of the amp. I'd personally just bias the amp cooler and get a GOOD quality 12ax7. JM2C's worth. Mike. | ||
| Matt White (mwhite) Username: mwhite Registered: 11-2012 |
Mike, thanks as you suggest, I'm not inclined to go the SS route. I am hoping that someone might know the root cause, or perhaps, someone has already designed some protection for the original circuit. I would still be interested in seeing the material you have regarding the SS conversion. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
I need to dig those out and scan them someday so I don't lose them! | ||
| A. Scott McIntosh (fez) Username: fez Registered: 01-2013 |
I had that failure in a 212-65. (The amp was manufactured in 1978) The amp just suddenly stopped. As i recall it was the third song in the second set. I shut it down immediately and avoided taking out the transformer. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Yeah, they had a bad habit of screwing up at the WRONG time. That's why the guys at MM came up with the novel re-route and went to the cathode driven amp with the SS driver. I don't personally like the sound of the SS ones but they ARE more reliable. They DO still take pedals well though and that's where we all seem to be. |