L55 Inductor Anomaly

[zipplok]

I upgraded the crossovers in my pair of L55's and followed the schematic to the letter paying particular attention to inductor placement. The only part I did not replace was the four lead 3mh inductor. (autoformer) The resulting sound with the tweeter attenuator switch set to medium or high was less than satisfactory.....somewhat rolled off and distorted. The only position providing a listenable sound was the low setting. The tweeters are still good and the woofers have been reconed. Could I just split the two pairs of leads and replace the factory inductor with a pair of 3mh air core types? Should I assume that the inductor/autoformer is fried and no longer doing its job? I am a newbie to this science and have never seen an inductor with four leads. I would have a pair of very nice L55's if it was not for this one anomaly. Any advice would again be greatly appreciated. Thanks in advance, Zipplok

[Don C]

You should probably measure the dc resistance of the inductor. Did you replace the switch too? That's another possible trouble spot. If you really need another inductor, I have a pair of L-55s, and I've been having an internal debate about parting them out. My cabinets are pretty crappy, and the woofers don't match. So maybe I could be persuaded to sell them in parts.

[Zilch]

If both updated crossovers are behaving badly, I doubt it's the inductors....

[DRG]

Could I just split the two pairs of leads and replace the factory inductor with a pair of 3mh air core types?

No. They are tapped autotransformers. I've long since forgotten the tap points on the LX8 and LX15.

[zipplok]

Thanks Don C and Zilch!! Both crossovers are behaving the same way. The previous owner of these has since told me that his house was hit by lightning while these were hooked up to his stereo inside. The switches do sound like the possible culprit as the inductors appear to be ok but the switch contacts are a bit "burned". I usually replace all of the parts on the boards when upgrading but these switches appeard to be a type not easily found. I will open them up again and check the contacts and go from there. Thanks again, Zipplok

[zipplok]

Hello Don C. If you decide to part out your L55's, I would be interested in buying both crossover assemblies. Let me know. Thanks, Zipplok