Finally: some pics.

[brad]

Pics 1 & 2: A vintage MXR 6-Band E.Q. that I stuck some Burr Brown opamps in.  The original blue finish was nearly completely scratched off and has the name "N.Pino" written on the bottom -so I stripped it off and resprayed it metallic gold with a few coats of clear on top.  It used to be my secret weapon on bass...but unfortunately it's probably going to end up on ebay because I don't use it anymore.

Pic 3:  Red Llama clone built in a HairForceOne box!  Looks nice on the outside...but the inside is a bit bird-nesty from the fact that the circuit board is on the bottom half...and the pots and switch are on the top!  There had to be enough wire length to allow battery changes.  It sounds great on guitar, but I don't use it now that I only play bass.  I'm willing to swap if anyone's interested -PM me!

Pic 4: My home made Upright Bass pickup made from a sheet of Jaycar aluminium.  The big flat part gets taped to the underside of the fingerboard.  It was my first attempt at using rivets and hammerite paint.

The end!  

[robbiemcm]

Are they sliding pots? If so... that's awesome. I wish I knew where to get some. Anyway, all look very nice, good work on the last one!

[Mark Hammer]

I used to love my old MXR 6-band back in the day.  I'm curious about how much of an improvement you felt the OP2134's made.

Though it is always doubtful whether one ought to trust what is silk-screened to the chassis ("These knobs go up to 11"), the MXR 6-band indicated 18db of boost and cut, which always struck me as exceeding their capability.  Personally, I used to use it an an overdive pedal.  Hell, I use to use it as my ONLY overdrive back then, pushing it with my Univox compressor.

This unit is certainly no magic bullet (and don't be in such a hurry for slider pots, they are no picnic my friend), but I am curious about whether it really does strive for more gain than it can deliver, and in so doing turns into a band-specific overdrive.

Incidentally, no holes were plugged during the making of this film - the MXR 6-band is on all the time, you CAN NOT switch it off unlike many other EQ pedals.

[Arno van der Heijden]

Does anybody know if a schematic exists for the MXR EQ?
I'm interested in it since I believe it is one of Tom Scholtz's secret weapons as well.

[brad]

I used to love my old MXR 6-band back in the day.  I'm curious about how much of an improvement you felt the OP2134's made.

The new opamps made it clearer -or cleaner-  sounding (which is to be expected result I guess).  I mostly used this pedal to shape the clean tone on my P-Bass, because it has the knack of making old strings sound like fresh strings, and the Burr Browns seem to have made the highs more pleasing to the ears compared to the old opamps.

To answer your query about the 18db of boost: I found that it was possible to get band specific overdrive within the upper limits of the slider's range if I really dug into my bass using fingerstyle.  However, I never needed to use such extreme settings for the tones I looking for.

Does anybody know if a schematic exists for the MXR EQ?
I'm interested in it since I believe it is one of Tom Scholtz's secret weapons as well.

The circuit board is double sided with traces going underneath where the sliders are mounted, so you'd have to practically dismantle the thing to be able to reverse engineer it.

[brad]

btw, the new opamps were just added for fun and to pass the time while I had the pedal disassembled.  I don't want to perpetuate any mojo myths!  The tone improved, but it's not as if Chris Squire started coming out of my amp.

[petemoore]

Just a question here...
 Would running 'x' eq at 18v provide an advantage..more clean headroom for instance?