kienlen

Well, Bob Crites has these as well for $12 each. I'm just going to order them from him because he's been very responsive to all of my questions and I love giving people my business when they are very helpful. And while I'm sure they could go without the zener diodes if they had a responsible owner, I'm just going to put new ones back in. These things lead a very tough life in the fraternity house. And I don't want to have to fix these any more often than I absolutely need to. The physical condition of the cabinets would make anyone who cares enough to read this forum break down in tears. But that's part of my attraction to them. Anything that can take this much physical and electrical abuse earns my respect.

Well, when I unhook one of the zener diodes (taking care to make sure that doesn't touch it's mounting plate), everything works fine. Bob Crites mentioned that he's only seen one other zener diode go bad. Looks like I've got case number two. Couple other questions, if people don't mind ... both of my tweeters have fuses soldered into the wires from the crossover to the drivers. Is that normal, or did someone add that along the line? These are second-hand speakers that have been used in a fraternity house for something like 30 years. Is the fuse necessary since Bob Crites mentioned that the point of the zener diodes is for tweeter protection? And a somewhat obvious question ... anyone know where I can get a couple of replacement zener diodes? Thanks to all.

I sent Bob Crites an email asking him the same question. He replied with the same answer as djk, above. So, this morning I'll do this and report back. Also, someone sent me a private message asking which crossovers I have, and they are Type AA, just for the record.

Hmmm ... not having a lot of luck here. Got the new caps from Bob Crites, soldered everything in, loosened and re-tightened all the connections. The one crossover is still producing a very diminished tweeter volume. So, I double-checked everything by swapping the tweeters again and it still seems to be this one crossover. Is it possible that the 245 micro Henry inductor is bad or that the weird zener diode contraption went bad? Anyone have a way to test those parts other than swapping them out?

Plugging my other tweeter in seems to produce the same results. And the tweeter from the "bad" crossover sounds fine when plugged into the "good" crossover. So, I have ordered a rebuild kit from Bob Crites. Thanks for the help.

Hi, I've got an old pair of La Scalas and one of the tweeters is acting odd. It isn't completely dead, but the sound is so soft that you need to put your ear up against it in order to detect that it is producing any sound at all. They appear to be the K-77M with square magnets (although the "M" isn't printed on them at all). I have disassembled the tweeters. The diaphram appears normal to the naked eye, but I admit I don't know what a "bad" diaphram would look like. Resistance across it a touch over 6 ohms. Anyone have a clue what's going on? Thanks, Stu