Nutrino x3

[Rich_S]

Hi, all you desciples of MadBean.  For my first post, I present three Nutrinos I built.  I'm a huge Andy Summers fan, and his tone on the 2007 tour sold me on the uh... overdrive pedal after which the Nutrino was designed.  Mine would be yellow, in honor of my favorite (but not quite "there" yet) modded SD-1.

As soon as I said I was building myself one, a buddy jumped on the bandwagon.  He wanted a green one.

Then my wife got involved with a charity auction at our kids' school, so I decided to build a third to auction off.  I grabbed some Lake Placid-ish duplicolor for that one, since I've recently been obsessed with LPB Telecasters.

I built them all what I believe are the black E6 componenet values (which the mighty Bean kindly added to his instruction sheet).  Finding them a bit fizzy, I then added the Burst version's  47pF cap across the diodes.  Still asymmetrical, though.  I also added another 47pF to ground at the input to reduce radio pickup - these beasts sound great but they are noisy.

Mine was the noisiest, so it got a few more minor mods to quiet it down, but without changing its sound much, if any.  It has now replaced my SD-1 (not to mention a BB  Preamp) in the overdrive spot on my pedalboard.  I use it for a combination of dirt and clean boost, mostly for solos. It's bright and gainy, but never fizzy or shrill.  It lacks the TS midhump that I hate, and it's lows are chunky without being bloated.

The yellow and green boxes were bought already powder-coated from Small Bear.  (The green powdercoat was very brittle, which explains the clunky-looking bezel and washer on that one's LED.)  Graphics on all three pedals are inkjet waterslide decals with Krylon satin clear acrylic over top.  "Drive" and "Volume" are pretty apparent, the center tone control is "Glass".  I figure if Mr. Lovepedal can make up new names for standard controls, I can make fun of them with icons.

As so... I give you three Nutrinos:

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[madbean]

Rich, these are great! Glad to see the finished products after talking to you about them a while back. I am still somewhat puzzled by the noise issue. I do recall I had a TS PCB from Tonepad a few years ago that no matter what generated lots of whooshing noise (even after changing out some parts). It could be a bad component, but it's hard to make an educated guess. You pretty much have to get the audio probe out to see if you can isolate the point where the noise is introduced.

Anyway, the flat response is helped by the 5k used in the tone control. It narrows the sweep of the filtering some into a more usable range. Plus, the reduction of the filter cap just before the tone section to 150n (or whatever) pushes up the massive roll off the first order filter creates before the active tone control.

Keep up the good work!

[Rich_S]

It seems there are a couple of noise sources.  The radio interference come and goes, so it's hard to quantify, but a 47pF across R1 has reduced it.

11_Gauge over the the TDPRI "Burnt Fingers" room suggested replacing R3 & C3 with 2.2K  & .1uF.  This help reduce the hiss & hum I was getting, without taking to much of a hit on the gain.

I also tried 11-Gauge's suggestion of lowering the input impedance by lowering R2.  Mine is about 570K right now, but I didn't hear any reduction in noise.  I could afford to drop the input Z, since I have a buffered pedal in front of my Neutrino - those who drive a passive guitar straight into it might not want this mod.

At the risk of some embarassment, I'll tell you the biggest noise source I found... a ground loop in my pedalboard.  For a long time, the noise seemeed to come & go with the Neutrino, but after some further experimenting, I found a source independent of the pedal.  I have an old Boss TU-12H tuner, and added my own external stomp switch to mute the amp signal while tuning.  (I've had this tuner so long that stomp-box tuners like the TU-2 and Pitchblack didn't exist when I got it.)  When in "play" mode, my tuner switch was supposedly isolating the tuner from the audio chain, and grounding its input to keep it from blinking as it attempted to tune noise.  Something in this scheme was introducing a ground loop through the tuner, and making the whole board noisy.  Once I rewired that, it quieted the whole board down.
 
Next time I have my Neutrino off the pedalboard, I might go back to the original component values, to see if it's OK now that the board is fixed.  On on the other hand , if it ain't broke...

BTW, the OTHER two Neutrinos I build are in the hands of a couple of good friends who are also experienced amatuer players.  I'll share they're reactions to the pedals as soon as they get back to me.

[Rich_S]

May 2010 Update:  I just got back from a 25th reunion gig with my old college frat-party-and-bar band.  Band members (some of whom hadn't seen each other in 25 years) came came from as far as upstate NY, Dallas, and San Francisco to Philadelphia for 2 days of 80s-style rock & new wave and plenty of sophomoric behavior.  We held a six-hour rehearsal on Friday, and played a 1-hour set at a reception for the Drexel University Class of '85 on Saturday.

This was the first time I used my Nutrino in a full band setting, and it was brilliant.  On it's own, it strikes me as a bit fizzy, but man does it slice through a band mix just right.  It was way better than the Xotic BB Preamp I used last year.  The BB has a mid-hump that I don't like.  You can dial it out, but I never saw the logic in dialing out a characteristic of the BB to make it sound like my E-clone.

If you're interested, search "ETC Drexel" for video clips of the band, two from last years Class of '84 shindig, and one vintage clip from 1985.  If anyone manages to post new material from this year (featuring my MadBean Nutrino) I'll post an update.