Rerurn to Romy the Cat's Site
In the Forum: Audio Discussions
In the Thread: Initial thoughts about new/old Lamm ML2s
Post Subject: Cracked, all rightPosted by Paul S on: 8/14/2008
Well, most metals in air simply corrode over time; we all know that. And running a little current through it can hasten the process. To pick an extreme example, I lived at the beach for nearly 30 years, and ALL connections were constantly going bad there, a real PITA. I figured I would not have problems like that here, ~ 20 miles inland, and indeed, it's been nothing like that. Rather, it's just as I've said.
Sauce? I ONCE tried "Pro Gold" on tube pins, several years ago. Never again! No, these were cleaned the usual way, with Q tips, little plastic dental tools and LPS "no-residue" contact cleaner, using magnification.
Here I am, looking again. Both 5651s have cracked bases, and both cracked in exactly the same area, along the pins And, yes, it does seem very unlikely, if only because I am very careful and painstaking with the gear, and I was not at all "rough" with these tubes, which are NOS RCA 5651WA, supposedly "mil spec", installed in April of this year. Also, as I said, this is the first time this has ever happened to me, with ANY tube.
I post here just to share my experience and because it's the only place I know to get intelligent feedback on the ML2, despite the fact that there are supposed to be so many "out there".
BTW, lots of the NOS tubes I get have pins that are "mottled", like they were brought up to a high temperature and air cooled, and I always assumed this is due to the glass manufacturing process versus the pin metal. I have never noticed any further "burning" of pins that I have recognized as such, however, including with these amps.
But I suppose it wouldn't hurt to replace the tube sockets, if that's what you are recommending.
Best regards,
Paul SRerurn to Romy the Cat's Site