# MXR 10-Band EQ Mod



## hollowbody (Jan 15, 2008)

I've read in a few places that people have these pedals modded to reduce noise when engaged. This guy on the interwebz says that after the mod (with a slightly less noisey op amp), he was able to get these results:


StockModdedImprovement*Flat*-107.5 dBV-111.3 dBV3.8 dB*Weighted*-86.7 dBV-98.1 dBV11.4 dB*Worst-Case*-71.5 dBV-76.8 dBV5.3 dB

Sounds like a pretty decent improvement, especially considering he wanted to use an even less noisey chip, but it wasn't available.

I have one of these EQs and really like using it for tone-shaping, but it does add a little bit of noise, which then become a LOT of noise once the pedal hits the overdrives. Anyone know of a place where I can ship this off to get it modded and what it would cost? My soldering is pretty rough and I'm definitely NOT comfortable with SMT. Pickup wires to pots? No prob. This is out of my league, though.


----------



## mhammer (Nov 30, 2007)

If it is a matter of soldering discrete components, _*fuggedaboudit*_. I wouldn't touch it either. But chips are actually not _that_ bad. SMT devices are "sweated" into place. So if you have:
1) some solder wick to remove the existing solder
2) a soldering iron of reasonable heat (35-40W is about right) for Rohs parts) and reasonably small-enough tip diameter to get in there (i.e., not a big wedge head for plumbing repair, or an instant-heat soldering "gun" for repairing amps)
3) a toothpick to hold the chip lined up with the solder pads
4) a teeny bit of liquid solder flux to help with the sweating into place

AND you are neither overcaffeinated, suffering from Parkinsonism, or going through the DTs (i.e., your hands are reasonably steady enough to play "Operation"), you can probably replace the chips. Digikey (which has a Canadian office and can certainly deliver quickly to the GTA) has the SMT version of the 837 in stock for [email protected] http://www.digikey.ca/product-detail/en/LM837MX/NOPB/LM837MX/NOPBDKR-ND/1847673 and has the 1664 in stock for even less http://www.digikey.ca/product-detail/en/OPA1664AIDR/296-35039-2-ND/3674882


----------



## hollowbody (Jan 15, 2008)

mhammer said:


> If it is a matter of soldering discrete components, _*fuggedaboudit*_. I wouldn't touch it either. But chips are actually not _that_ bad. SMT devices are "sweated" into place. So if you have:
> 1) some solder wick to remove the existing solder
> 2) a soldering iron of reasonable heat (35-40W is about right) for Rohs parts) and reasonably small-enough tip diameter to get in there (i.e., not a big wedge head for plumbing repair, or an instant-heat soldering "gun" for repairing amps)
> 3) a toothpick to hold the chip lined up with the solder pads
> ...


Hmmm...I might have to pop open the pedal and take a good, honest look at the board and see what I think I can reasonably do with it. 

I've recently re-organized my pedalboard, and I'm taking it to rehearsal tonight, so I'll see if any of my re-jigging has resulted in a lower noise-floor. If it's acceptable, I might make-do for now. If not, I'll have to work up the courage to at least try it myself. Heck, for a few bucks, I might as well. At least I know MXR/Dunlop has a very good customer service department that helped me out with a wonky Stereo Chorus a couple years back


----------

