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Harbinger Two

FX TYPE: Univibe

Just how lazy and inefficient am I? I’ll let you pass judgment. I first started working on what would become the “Harbinger 

Two” around 2013. I knew I wanted to do a Univibe in a wah configuration, and I knew more or less how it should be done 

(mostly less). Enter an endless parade of prototypes over the next 5 years. Mind you, I was not working on this constantly 

- every year I would pick it back up and try to get it right. And, with each iteration I ran into some kind of problem. It went 

like this: find problem, how to solve? Lemme just work on something else. The problems ranged from not understanding 

how to control the LFO speed properly, bad voltages, bad response to speed control, etc, etc. But, I never gave up on it 

and eventually I solved all the problems. And, I’m glad I did because this is a really good DIY project.

The Harbinger Two is very much a port of the Harbinger One into an expression control. If you’ve built the HB1, you can 

certainly build the HB2. If you’ve never built a Univibe, you can certainly build and HB2, as well. But, and I want this to be 

very clear: this is a time-consuming project. Expect to spend a few evenings putting it together. It’s not something you can 

build in a single day and it requires patience and commitment. IOW, go slow and get it right the first time!

Details about the design: The Harbinger Two (like the One) does depart a little from the traditional Univibe design. It 

includes an JFET buffer for a louder and brighter input option (the second input option is the stock Univibe). It also runs 

all the audio at 18v instead of a regulated 15v. This gives the audio portion a little added headroom at the expense of a 

small voltage drop (see the Voltage chart below for an explanation). The LFO section runs from regulated voltage like the 

Univibe. 

And, like the One, the HB2 only requires a 9v DC supply to operate. Lastly, the HB2 adds a new tweak: the Drag switch, 

which creates a ramp down effect with mod rate.

Controls

SPD:

  The rate of the modulation from fast (toe down) to slow (heel up).

INT: 

The intensity of modulation.

VOL: 

Output volume.

C/V: 

This switch selects between a chorus effect (modulation mixed with dry signal) or vibrato effect (pitch modulation 

only).

MOD/VIN: 

This slide switch selects between the traditional input and a JFET buffer input. The JFET buffer has more out

-

put volume and is brighter.

DRAG: 

This switch creates a slight delay and ramp-down effect of the modulation rate when going from Toe to Heel posi

-

tions.

GAIN: 

This trimmer sets the brightness of the LFO-driven bi-pin lamp.

OFFSET: 

 This trimmer lets you adjust the ramping of the lamp’s brightness.

Terms of Use: 

You are free to use purchased 

Harbinger Two 

circuit boards for both DIY and small commercial operations. You may 

not offer 

Harbinger Two 

PCBs for resale or as part of a “kit” in a commercial fashion. Peer to peer re-sale is fine, though.

Summary of Contents for Harbinger Two

Page 1: ... design The Harbinger Two like the One does depart a little from the traditional Univibe design It includes an JFET buffer for a louder and brighter input option the second input option is the stock Univibe It also runs all the audio at 18v instead of a regulated 15v This gives the audio portion a little added headroom at the expense of a small voltage drop see the Voltage chart below for an expla...

Page 2: ...Layout ...

Page 3: ...Traces There is a layout error regarding Q15 Please see the Notes section for the correction ...

Page 4: ...3 1uF REG1 LM7815 R14 220k R45 100k C14 470pF Optical R15 4k7 R46 100k C15 1uF OPTO1 2 NSL 32 R16 100k R47 4k7 C16 1uF Illumination R17 47k R48 4k7 C17 4n7 L1 Bi Pin Lamp R18 4k7 R49 47k C18 1uF LDR R19 100k R50 47k C19 1uF LDR1 4 see notes R20 4k7 R51 22R C20 1uF IC R21 4k7 R52 27k C21 1uF IC1 LT1054 R22 100k R53 100k C22 10uF Switches R23 47k R54 27k C23 10uF C V SPDT R24 4k7 R55 1M C24 100n DRA...

Page 5: ...00k 13 Carbon Metal Film 1 4W LT1054 1 220k 3 Carbon Metal Film 1 4W SPDT 2 On On 1M 5 Carbon Metal Film 1 4W DPDT 1 included with PCB 2M2 1 Carbon Metal Film 1 4W 500R 1 Bourns 3362p 330pF 1 Ceramic MLCC 25v min 250k 1 Bourns 3362p 470pF 1 Ceramic MLCC 25v min 50kB 1 Solder Lug 9mm or 12mm 4n7 1 Film 25v min 100kB 1 Solder Lug 9mm or 12mm 15n 1 Film 25v min 100k ICAR 1 Wah POT 100n 3 Film 25v min...

Page 6: ...ctronics mybigcommerce com alpha single gang 9mm pc mount 12mm pots 50kB 100kB http smallbear electronics mybigcommerce com alpha single gang 12mm solder terms Wah Parts Your best bet is to find a used Crybaby and gut it You can often find them in the 30 50 range The advantage is that is will cost less than purchasing an empty shell AND ICAR pot jacks etc Plus the wah pot is already mounted which ...

Page 7: ...t the half rounded side faces up instead of down The BS250p is slightly flatter than the typical T0 92 tran sistor casing Use this guide In the corrected version the BS250p marking on the transistor casing faces the red arrow DC Jack The placement of the two NSL 32 devices is not really optimal in terms of overall design but it s what worked with this PCB layout If possible one of the external nut...

Page 8: ... It took about 15 minutes to drill the holes PS I also had to drill out a larger hole for the DC jack since none of my jacks fit the existing hole I used a drill press and even with that I had to use some forceful downward pressure to punch through After drilling I had a lot of burrs that required clean up Using my Xacto knife an old pair of wire cutters I didn t care about and deburring tool I wa...

Page 9: ... controls are interactive Use this procedure to calibrate the lamp Turn Intensity and Volume controls all the way up Set the Speed control at about half way Turn the GAIN control up until you get moderate but not overly bright lighting of the lamp Now adjust the OFFSET control to find the sweet spot for the vibe where you get the most lush and swirly sounds The OFFSET will set the lower floor for ...

Page 10: ...it exactly like the typical madbeanpedals bypass You will also need to add a CLR wired to the positive tab of the DC jack Speaking of switches if you are buying a bypass switch for your shell try to get a long shaft one The normal 3PDT switch is a bit too short and requires extra padding to actuate These switches eliminate that problem DPDT http smallbear electronics mybigcommerce com dpdt 316 b p...

Page 11: ...Build Pics Note These pics were taken before I realized Q15 was wrong on the layout so ignore it ...

Page 12: ...4 MPF102 Q15 BS250p REG1 7815 C 14 73 C 9 2 C varies D 17 5 D 9 4 In 17 5 B varies B 9 08 B varies S 2 77 G 0 Gnd 0 E varies E 8 13 E varies G 0 S 9 26 Out 14 74 Because the audio portion of the Harbinger Two is unregulated you may see some small fluctuations on the 18v rail This is from the changing current demands of the LFO as best I can tell the total current draw does vary some with different...

Page 13: ...Schematic ...

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