Martin Logan Sequel problems / repair

[stargeezer]

Hello all,

I have a pair of Sequels that have been working flawlessly for a few years now. Yesterday I was listening to a few new albums and they sounded great as usual. Before leaving the listening room I powered everything down as usual and today went in to listen to some music, fired everything up and both speakers were not working. All connections, amp channel, internal fuses etc was checked. My backup speakers worked fine so I know the system was working fine. The sub woofers on the speakers were still working just like if you unplugged the power from the speaker. Now I have built a lot of amps and speakers so I am not a newbie here so I am looking for anybody that has experience with repairing these speakers. Not sure why both would fail at the same time. I have very stable power in the house. Any idea's? Any schematics available for these on the web?

Thanks,
Brian.

 

[shoafb]

you likely already checked this but, you do not have the panels plugged in to a switched outlet do you?

 

[JonFo]

If it's not AC power related (the plug is pretty loose on mine, and occasionally falls out), it could be a music-sense circuit related problem.

That vintage ML had some of the very first 'music sense' circuitry to enable the ESL energizer only when music was playing. But I'd guess by now a cap in that circuit could have varied its rating enough to be flaky.

There might be a schematic of the Sequel on this site, see http://www.martinloganowners.com/forum/forumdisplay.php?77-ML-Schematics

There is detailed schematic for an SL3 (follow-on to the Sequel) step-up board that shows the detail for the Music Sense circuit.

 

[stargeezer]

Hello all,

I replaced the transformers and all is well. Not sure why they both went at once, maybe a spike but I'm just so glad the parts were still available.

 

[JonFo]

Thanks for following up with an update. Can you please be more specific as to which part exactly went, maybe even a pic of the old one.

My guess would be you experienced a power surge on the AC line, so maybe a good idea to run surge suppressors for the speakers or the whole house.

Thanks,