Summit X panel muted and distorted

[Rolf]

Hi all.

The other day I failed to switch off my amp before changing an interconnect which caused a sharp crack through one speaker after which the panel sounds muted and distorted (over the entire panel). Bass is fine. Earlier I did notice that said panel buzzed and distorted on loud mid range (e.g. vibraphone from Dave Grusin/Discovered again), but as the other speaker does the same (though not nearly as much) I thought that I was just pushing it a little too much :rocker:

I have PMed a guy here about a pdf-manual about how to take the panel off, so I can swap them and see if it's the panel or the electronics, but does anyone have any ideas what might have happened? It's Easter and I'm quite unhappy (and ashamed) so if it's "just" a bad connection I can fix it quick.

Cheers, and happy Easter,
Rolf

 

[sleepysurf]

I just sent you my copy of ML's Summit disassembly instructions.

However, I think it’s more likely you fried something in your amp, or the ML power supply/crossover, rather than the panel itself.

Have you swapped left-right outputs from your amp to see if that confirms the speaker is the entire source of the problem?

I would also check with your local ML dealer (if there is one) or call ML directly for trouble-shooting tips, before actually disassembling one, as it's quite a process!

 

[Rolf]

Thank you Sleepysurf! Yes, I swapped channels and the problem stayed with the speaker panel. I also unplugged the speaker and left it to discharge completely, but that didn't help either. When I find out the problem and get it sorted I'll post the findings.

Cheers,
Rolf

 

[JonFo]

Panels are pretty sturdy, so I'm going to guess a capacitor blew in the crossover, or the step-up transformer is half-fried.

So I'd take the speaker to a dealer and ask them to check the electronics. Actually if the electronics, including the step-up are on a single removable panel, then just take that.

 

[Rolf]

Thanks for your inputs. Based on the service manual I was able to swap the panels in less than 10 min. and sure enough, it's the electronics that have problems (the other panel sounded exactly the same when mounted on the faulty speaker, and it sounded pristine on the other). The Danish importer and ML expert is about ½ hour's drive away from me I just found out, so I'll refrain from opening the speaker box and leave that to the experts. Besides, the Allen bolts used on the speaker are Imperial sizes and not metric, so I might risk ruining the bolts.

Happy Easter to all

Rolf

 

[Rolf]

At last the broken Summit X is back in full working condition and sounding wonderful. It turned out to be the high voltage supply and some capacitors which had broken. I was told that over time capacitors can go bad (due to heat if you play louder than background music on a regular basis). And if a capacitor blows it can affect the other electronics. Being about 8 years old I'll take the other speaker for a "cap check up" as repairs were NOT cheap (just under 2.000 USD) and took many week. And from now on I'll always unplug one speaker lead from the speakers before changing cables to make sure that no "jolts" or other grunge is sent to the speakers.

Cheers,
Rolf

 

[twich54]

Rolf,

Glad you're back up a running but man that repair bill seems mighty high to me, $2000 USD ? !!

 

[Rolf]

Specifically the "high voltage module" was just under $1.000 and "other parts" were about $350 and then labour on top. Denmark is generally expensive, but I guess these parts are not cheap even in the US, so please take care not to make the same mistake I did.

Cheers,
Rolf

 

[Tosh]

At last the broken Summit X is back in full working condition and sounding wonderful. It turned out to be the high voltage supply and some capacitors which had broken. I was told that over time capacitors can go bad (due to heat if you play louder than background music on a regular basis). And if a capacitor blows it can affect the other electronics. Being about 8 years old I'll take the other speaker for a "cap check up" as repairs were NOT cheap (just under 2.000 USD) and took many week. And from now on I'll always unplug one speaker lead from the speakers before changing cables to make sure that no "jolts" or other grunge is sent to the speakers.

Cheers,
Rolf

As you acknowledged, you blew out the caps in the single event of leaving the amp on while changing an interconnect. The lesson is: Switch OFF the amp when checking connections.

All that other stuff about heat and cap checkup or whatever is just nonsense.