Monday, December 5, 2016
DIY Z VEX Super Duper 2-In-1 pedal and stripboard layout (schematic)
If you want to go straight to the stripboard layout, scroll to the bottom of this post.
I used Iviark's nice layout as a starting point, and did some research to reach what I believe is the "final" schematic or layout.
The main difference from the Super Hard On is the input caps need to be reduced to .01 uF as per Zachary Vex's post on The Gear Page. If you use the stock 100n SHO input caps, the subsonic frequencies can cause the pedal to "drop out" or "shudder" at high gain settings. The slightly smaller input cap value cures this problem, so use it.
Also, the second SHO in this box, the "red side," you need to drop the 100K bleeder resistor completely, just remove it from the layout, and add a 50K volume pot, the master volume control, which is the center knob in my build and Z Vex's also. If you look at gut shot pics of the 2-in-1 you can see that this pot is a 50K, not a 100K. This gives the "red" side a slightly warmer top end. I think a cool mod for a SHO would be just to use a 50K bleeder resistor in place of the 100K if you think the sparkle is too much (which I sometimes do).
My stripboard layout posted here includes all these corrections.
I built two of these, one with mid grade black Nichicon output electrolytic caps, and one with the Nichicon Fine Gold output caps. The Fine Gold caps give the pedal more clarity, so I chose to build that one up first, and that would be my recommended part.
I used the ceramic input caps because Zachary uses those in his pedals, I figure maybe it's a small part of the tone. If you want a super transparent circuit, you can replace those with polypropylene, paper in oil, or etc caps for super transparency. I built up a Landgraff Boost with caps like that, and it's probably the most transparent boost that I have heard. By the way, the Landgraff is simply a rip off of the ZVex circuit, the only difference is the brand of FET employed, and the capacitor type choices. Surprisingly, these small differences are audible in a side-by-side comparison, which I have done.
This would not be my recommended build for a first timer, due to the complexity of the offboard wiring. I would get comfortable with single boost pedals before attempting a dual footwsitch circuit.
I am sort of a clean boost fanatic, I have almost a dozen of them lying around here. This one very quickly has earned my attention.
The main thing that's great about the 2-in-1 is the versatility of tones available in this very compact box. The single SHO, the "yellow" side, is a pretty bright and sparkly boost. Good for clean tones, maybe, in my opinion. The "red" side with the master volume has a slightly warmer tone, due to the output pot impedance, and due to the fact that you can dial in more clipping with the master volume at lower levels. And of course you can ram the yellow into the red for even more coloration, or stacking of tones. The "red" side seems to be the more special part of this pedal, for my purposes.
The really interesting part of this circuit as a distortion device is it's a completely flat frequency, broad band response. You can dial it in to a medium gain at unity volume, play lightly, switch the pedal ond and off, and the true bypass tone sounds almost identical to the ZVEX tone. Then you play harder and the clipping shows up. It doesn't "hump" your tone like an overdrive pedal. So you can use the controls available to add any combination of volume changes, and clipping changes, that you like, along with whatever your amp and your other pedals are doing. It's just a fairly elegant part of the gain staging of the entire guitar rig. It's transparent enough that it doesn't mess with your tones too much. It seems like most tube amps like to be hit a little bit on the front end, more often than not. Especially at low or medium volume, when the output section is not working as hard.
I have used other clean boosts that were way too sparkly on top (Boost N Buff), and some others that seems slightly too dark and mushy (Keely Katana), my favorites seem to lie somewhere in between. This one gives you a little of both, plus more control over the grit. Sort of like a Fulltone Fat Boost, but more clear and transparent. A feature I am sure of the simplicity of the circuit design.
I would not use this as my main distortion or overdrive, it is not a substitute for those. But I think every pedalboard deserves a boost, and this is a great one. My simple test was to run my Agile les paul into my Blackstar Studio 20H amp head. When I turned the boost on, the clean channel just sounded better. By itself the amp was slightly dark and soft sounding, but the 2-In-1 just firmed it right up and gave a solid and authoritative tone, when used as a buffer or a moderate boost. There's a lot of subtle, tweaky ground to cover with the three controls and both footswitches, which made me happy. You're not just stuck with one sound. It didn't seem to do much for the distortion channel, I will stick to my overdrive type pedals for that kind of boosting, where the mid-humping type of sound comes in handy.
My favorite boost to date seems to be the Xotic EP Booster, which has a spot on my large pedalboard. And the DAM Red Rooster, which is more of a character germanium treble booster on the front end of things. The Landgraff boosts I built are among my most favorite "one knob" boosters, along with an honorable mention of the MXR Micro Amp, which I used for some time.
The question to me seems to be, how does this compare to the Super Hard On? I found the single, stock SHO to be slightly too sparkly on the top, which is why I favored the Landgraff versions. That SHO/Boost 'N Buff presence bump can seem sort of tacked on, or artificial, when running a good tube amp. But with the master volume "red" side on this pedal, this one seems even more versatile than the Landgraff, and better sounding than the single SHO. I think this pedal is more useful than the seemingly "too simple" Super Hard On, and depending on your build, not even that much bigger, or perhaps the same size, so why not?
I will also recommend to use the top jacks if you can manage, it makes for cleaner cabling than the side jacks on this sideways pedal. Happy soldering and good boosting to you. :-D