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Old 09-21-2021, 07:06 AM
MikeBmusic MikeBmusic is offline
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Default Latest gear issue - mixer

I've had my Mackie PRO FX-12 mixer for 8 years now, gets used at least a couple of dozen times a year. Never had any issues with it, but I do know someone who had a newer model and had issues with a bad channel and non-working reverb.

So a few weeks ago, at the open mic I host, the 2nd-to-last performer shouted into his mic and there was some awful distortion from the right side speaker. I just turned it down via the volume control on the speaker.
Later, I tested everything, thinking it might have been a bad cable (I had joined 2 XLRs that night), but no, it turns out it is the right-side output on the mixer itself. I've been daisy-chaining the 2 PA speakers since then, but it has made me nervous that whatever happened to that one output could eventually happen to the left side too. In an emergency, I could hook up to the monitor output (I haven't tried it to ensure it doesn't have the bad sound from the right side output, but guess I should!)
Guessing it is some component in the output stage of the mixer?
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Old 09-21-2021, 09:42 AM
RRuskin RRuskin is offline
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Are you are certain the distortion is from the mixer and not the amp section of your speaker system?
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Old 09-21-2021, 11:10 AM
shufflebeat shufflebeat is offline
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Quote:
Originally Posted by MikeBmusic View Post
I've had my Mackie PRO FX-12 mixer for 8 years now...
That's not too bad, get thee to a mixer-fixer.

For testing purposes, which might also shorten the repair time/cost, get a leads tester - test leads, swap outputs, does the problem persist on one output, try other input channels.

Intermittent problems can be. PitA to diagnose so the better you can isolate and describe the problem the better.
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Old 09-21-2021, 11:50 AM
MarkF_48 MarkF_48 is offline
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Older gear is fun, sometimes not....

Working backwards to see if there's a particular section that's acting up....

- Have you tried plugging headphones into the mixer yet to see if get the distortion? The headphones pick off the signal prior to the last stage before it hits the output jacks.

- The MON out is a step further back in the signal chain also. It combines right and left inputs. Try that output to see if it's distorted.

- Graphic EQ bypassed or in make a difference?

- If the mixer has USB, try feeding audio in with USB and see if that distorts.

- I have an old Behringer mixer that has a few pushbuttons that are prone to getting crapped up and sometimes causing the audio to be intermittent and crackly (could sound distorted). A short shot of De-Oxit down the side of the switch and operating it a bunch of times usually clears it up until next time. The 'BREAK' PB switch on the Mackie could get flaky and affect the audio on one side. Maybe a shot of cleaner and function it a few times may help(?)

Schematics...............
https://elektrotanya.com/mackie_prof.../download.html
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Old 09-21-2021, 08:27 PM
Rudy4 Rudy4 is online now
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"8 years"

Time for a new mixer. It always causes a grimace to say that, but this stuff isn't a vintage point to point hardwired Fender Deluxe.

"Modern" electronics has a shorter lifespan than what we would like it to have.
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Old 09-21-2021, 09:11 PM
B. Adams B. Adams is offline
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Mackie, despite their marketing, was not as rock-solid as some people think. Sure, they build decent gear, but it was made to hit a price point rather than a focus on quality. It sounds like yours is dying. And I think you're right, the other output probably isn't too far behind.

A lot of Mackie components are proprietary. I know when I was tasked with repairing a 24.4 a few years ago, I couldn't find new pots. They're a proprietary taper, and nobody I could find had any in stock and no way to get them. The original manufacturer of the pots, Panasonic, would make me a new batch, but only if I purchased a minimum of 10,000 pieces. So off to the recycler it went.

Your problem sounds like something in the output stage, probably a bad cap, if I had to guess. If so, it's probably easily repairable, but finding someone to fix it economically might be tough. If you want to do it yourself, it might be a fun project and shouldn't cost too much. The hard part will be figuring out exactly which cap is the bad one. If I were in your position, I'd treat it as an experiment and a fun project, not a necessary repair.

In the meantime, I'd recommend you find a good replacement mixer and start using it. If you get the old one fixed, you'll have a decent backup. If not, you'll still have a new mixer that works.

I still have an old Peavey PV10 that goes out when I need something small and simple. It's been more reliable than any Mackie I've used. I don't know if the new ones are built as well though, I don't have any experience with them.
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