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Guitarfreak 1 October 2010

Need advice on this. When I adjust the volume on my FireBox I get crackling in my Left monitor. If I swap the cables at the FireBox outputs the crackling switches sides. I thought that it was a cable issue, but the cables have been replaced and the crackling remains. I contacted PreSonus about this and they said that the master pot is bad. My unit is no longer under warrantee so they want to charge me a flat bench fee of $75 plus shipping and two to three weeks of my time. NO THANKS!

It's a $3 pot and a 5 minute fix. I'll either fix it myself, live with it, or buy an upgrade interface a-la ONYX or something. What do you think?

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Comments

Guitarfreak Fri, 10/01/2010 - 09:23

Boswell, post: 354428 wrote: Don't underestimate the cost of a decent dual-gang log potentiometer, nor the time it would take to do a good job when changing that sort of thing.

A well-aimed squirt of contact cleaner lubricant should fix it, at least for a while.

Interesting. Before this I have never heard of a dual-gang pot. Do you think the job is worth 75 plus shipping and 2-3 weeks of my time without an interface?

Contact cleaner I do not have, WD-40 I do. Can they both perform this function or should I grab some contact cleaner to have around the house?

Guitarfreak Fri, 10/01/2010 - 20:52

TheJackAttack, post: 354433 wrote: WD-40 is not even close to contact cleaner. DO NOT USE it for such.

http://www.sweetwater.com/store/detail/DeoxIT

This is available in most hardware stores. It is good on motor parts as well as XLR/TRS/biamp/etc connectors.

Thanks Jack, I'll order some of that tomorrow or the next day. I should have some anyway for my build/mod projects.

djmukilteo Sat, 10/02/2010 - 16:12

GF: You said you swapped cables...."If I swap the cables at the FireBox outputs the crackling switches sides".
So the crackling is only on one channel output of the FB? Same output channel? Is the master volume a single knob/pot or both?
It's probably a dirty pot in which case open up the box to get to the volume control and spray the Deoxit inside the pot while moving it..(power off obviously)...and no WD40!....hinges and stuff...WD40 good stuff...not for cleaning contact surfaces though...

Guitarfreak Sat, 10/02/2010 - 18:39

djmukilteo, post: 354475 wrote: GF: You said you swapped cables...."If I swap the cables at the FireBox outputs the crackling switches sides".
So the crackling is only on one channel output of the FB? Same output channel? Is the master volume a single knob/pot or both?
It's probably a dirty pot in which case open up the box to get to the volume control and spray the Deoxit inside the pot while moving it..(power off obviously)...and no WD40!....hinges and stuff...WD40 good stuff...not for cleaning contact surfaces though...

Thanks. Yes, it has a single Master Level knob which controls both L and R outputs simultaneously. Apparently only the L output is noisy. Maybe when I get some of that contact cleaner I'll spray it on the end of the TRS and wiggle it around a little bit just on the small offchance that it's not a pot issue.

djmukilteo Sat, 10/02/2010 - 18:51

Well spraying the connectors is fine and always a good thing to do but if it's scratchy sounding when you rotate the pot it's dirt on the wiper which is a really common problem with pots...need to spray the cleaner into the inside of the pot which means getting to the back of the pot and squirtin that junk into the small hole in the case of the pot and then rotating the knob full position back and forth while squirtin!....

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