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MXR M87 having some issues.

Rickenmonster

Rickenmonster

Guest
Apr 5, 2013
683
122
Vancouver,B.C.
#1
I've read about others having issues with the M87 comp but counted myself as lucky. Changed up my pedals today and plugged everything in and now the LEDs on my M87 don't seem to work. All the knobs seem to work and I get LED action at power-up then nothing. I received a mail from the shop I got it from a couple months ago saying my 1yr warranty had just expired so I guess that's that unless any of you folk have any suggestions.
 
#3
I have read quite a few people are having very similar issues with that compressor. I am thinking that it might be a problem with opamp latch-up. Some opamps will latch with their output to the top or bottom rail if there is signal on the inputs before the circuit fully powers up.

I was testing some opamps that have been praised for superb audio quality a few months ago and had two different types of opamps latch-up when the power was applied. One of them would reset after several seconds and start working properly, but the other needed to have the power removed from the circuit… it would sometimes power up without a problem, but it was hit or miss. Some opamps that stay in a latched state for an extended period of time can be permanently damaged.

If that problem reappears with your compressor, remove the power plug from it for a few seconds while all of the other pedals are powered. That may reset the latching condition and the comp won’t have that power-up ‘thump’ from the other pedals to drive it into a latching state.

The other thing to try is contact MXR for service. I would think that with all of these issues they must be seeing, that they have remedied the problem and would make good on a warranty a couple months expired.

-Frank
 
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#4
Too bad about the problems reported with this pedal, it seems like a very nice compressor. I don't doubt MXR will repair or replace those that fail during the warranty period at least, but it does give you some worries for the long term.

I hate it when there is a known design issue or a bad batch of components and a manufacturer won't fix it just after the warranty period is over, Apple has done that to me twice. Mackie on the other hand took care of my mixer that failed years later, because of a bad batch of band cables for a certain serial number range. That's classy in my opinion.
 
Last edited:
#8
Rickenmonster said:
I've read about others having issues with the M87 comp but counted myself as lucky. Changed up my pedals today and plugged everything in and now the LEDs on my M87 don't seem to work. All the knobs seem to work and I get LED action at power-up then nothing. I received a mail from the shop I got it from a couple months ago saying my 1yr warranty had just expired so I guess that's that unless any of you folk have any suggestions.
Click to expand...

I have the very same problem. I get LED action when the pedal powers up, but when it comes to playing, the LED doesn't work at all. I've tried opening it to check the switch and it's ON. My warranty has expired already (and also I'm in South America so I don't think there's an MXR support team here,) and to top it all my pedal makes an annoying hiss when activated.

Any news on what might be going on? Please respond!
 

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