Martin Logan sl3 channel imbalance caused by bad Crossover transformer (t1). Need advice

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Active member
Apr 1, 2023
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Hello all,

I’ve been trying to figure out my channel imbalance lately but just haven’t had the time to tackle it until now. The t1 crossover transformer has gone bad and needs replacement. I am planning on refreshing both. What are my options to find a replacement part. Should I contact Martin Logan? I expect they might try and sell me on new boards all together which I am trying to avoid. Should I contact Hobart electronics? They used to make this part. Is there something else I should try for? I’ve seen other people with a similar issue but would like to do this in the easiest way possible. I just got them both recapped and restored a few months ago. New power supply boards would be worse case scenario. Thanks for any advice or guidance!!


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More than 10 years ago I was able to get one transformer directly from ML and solder it in myself. But the "easiest way possible" is to buy the whole HVPS board. Call ML and see what they say!
Probably a suggestion you might not want to consider, but have you considered going with an active crossover and adding a Class D-type amp to drive the low frequency drivers?

There are several threads on this forum about it - here's one I like:

A bit about my situation: I have a pair of SL3's that have seen pretty much ZERO use in the past 15 years. I also have a pair of untuched replacement panels for them. I reckon I have about 20 years of use left in them, once I get my system going again.

In the event of the crossover(s) failing, I absolutely plan on taking them active. The availability of affordable, incredibly flexible amps (like the Crown XLS1002) means we can basically create an Active SL3 very much like what ML has done with the Masterpiece series (with embedded Class D amps).

Just my $0.02