Mad Bean Pedals Harbinger Two User manual

Harbinger Two
FX TYPE: Univibe
Just how lazy and inefcient am I? I’ll let you pass judgment. I rst started working on what would become the “Harbinger
Two” around 2013. I knew I wanted to do a Univibe in a wah conguration, 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: nd 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 rst 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 ne, though.

Layout

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

B.O.M.
Resistors Resistors Caps Diodes
R1 22K R32 4k7 C1 1uF D2 15v Zener
R2 47k R33 4k7 C2 1uF D3 1N5817
R3 1M R34 100k C3 330pF D4 1N5817
R4 5k6 R35 47k C4 1uF D6 1n914
R5 1M R36 22k C5 1uF D7 1n914
R6 100k R37 68k C6 1uF Transistors
R7 47k R38 3k3 C7 15n Q1 2N5089
R8 4k7 R39 2M2 C8 1uF Q2 - Q10 2N5088
R9 3k3 R40 4k7 C9 1uF Q11 - Q13 MPSA13
R10 1k2 R41 2k2 C10 220n Q14 MPF102
R11 100k R42 220k C11 1uF Q15 BS250
R12 100k R43 2k2 C12 1uF Regulator
R13 47k R44 220k C13 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 DRAG SPDT
R25 100k R56 1K C25 100n MOD_VIN DPDT Slide
R26 4k7 R57 1M C26 220uF Trimpots
R27 4k7 R58 10k C27 100n GAIN 500R
R28 100k R59 1M C28 47uF OFFSET 250k
R29 47k C29 100uF Pots
R30 4k7 C30 100uF INT 50kB
R31 100k C31 4u7 VOL 100kB
SPD 100k ICAR
Enclosure
Wah Shell

Shopping List
Value QTY Type Rating Value QTY Type Rating
22R 1 Carbon / Metal Film 1/4W Zener 1 15v
1K 1 Carbon / Metal Film 1/4W 1N5817 2
1k2 1 Carbon / Metal Film 1/4W 1n914 2
2k2 2 Carbon / Metal Film 1/4W 2N5089 1
3k3 2 Carbon / Metal Film 1/4W 2N5088 9
4k7 14 Carbon / Metal Film 1/4W MPSA13 3
5k6 1 Carbon / Metal Film 1/4W MPF102 1 or, 2n5457, J201
10k 1 Carbon / Metal Film 1/4W BS250 1 *included with PCB
22k 2 Carbon / Metal Film 1/4W LM7815 1
27k 2 Carbon / Metal Film 1/4W NSL-32 2
47k 9 Carbon / Metal Film 1/4W Lamp 1 *included with PCB
68k 1 Carbon / Metal Film 1/4W LDR 4 *see notes
100k 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. Wah Shell 1
220n 1 Film 25v min.
1uF 11 Film 25v min.
1uF 5 Electrolytic 25v
4u7 1 Electrolytic 25v
10uF 2 Electrolytic 25v
47uF 1 Electrolytic 25v
220uF 3 Electrolytic 25v
TIP: You can use a 12v Zener instead of 15v (smallbear has 12v but not 15v Zeners). You can also
use no Zener at all - but only if you are careful to only use a 9v supply. The LT1054 an be damaged at
over 15v.

Parts Guide
15v Zener: https://www.mouser.com/ProductDetail/ON-Semiconductor-Fairchild/1N4744A?qs=sGAEpiMZZMtQ8nqTK-
tFS%2fD313Kx94AdFdSPLy44WWjs%3d
2n5089: http://smallbear-electronics.mybigcommerce.com/transistor-2n5089/
2n5088: http://smallbear-electronics.mybigcommerce.com/transistor-2n5088/
MPSA13: http://smallbear-electronics.mybigcommerce.com/transistor-mpsa13/
MPF102: http://smallbear-electronics.mybigcommerce.com/transistor-fet-mpf102/
LM7815: http://smallbear-electronics.mybigcommerce.com/ic-lm7815ct/
NSL32: http://smallbear-electronics.mybigcommerce.com/photocoupler-silonex-nsl-32/
LT1054: http://smallbear-electronics.mybigcommerce.com/ic-lt1054cp/
SPDT: http://smallbear-electronics.mybigcommerce.com/spdt-on-on-short-lever/
500R 3362p: https://www.mouser.com/ProductDetail/Bourns/3362P-1-501LF?qs=sGAEpiMZZMvygUB3GLcD7iDNlz%2f-
NDKompMEyhqEJhVo%3d
or, https://www.taydaelectronics.com/potentiometer-variable-resistors/cermet-potentiometers/3362p/500-ohm-trimmer-po-
tentiometer-cermet-1-turn-3362p.html
250k 3362p: https://www.mouser.com/ProductDetail/Bourns/3362P-1-254LF?qs=sGAEpiMZZMvygUB3GLcD7p0sIDtXd-
CwsKR9Dy6lj2rI%3d
or, (200k is okay): https://www.taydaelectronics.com/potentiometer-variable-resistors/cermet-potentiome-
ters/3362p/200k-ohm-trimmer-potentiometer-cermet-1-turn-3362-3362p.html
9mm Pots: http://smallbear-electronics.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 nd a used Crybaby and gut it. You can often nd 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 is a
BIG advantage. Tip: you do not need to spend a lot on a fancy Wah pot. In the Harbinger Two it only controls the bright-
ness of the LEDs in the two NSL-32.
smallbear does offer this shell: http://smallbear-electronics.mybigcommerce.com/expression-pedal-shell/
and, this kit: http://smallbear-electronics.mybigcommerce.com/expression-pedal-shell-kit/
And, this pot: http://smallbear- electronics.mybigcommerce.com/wah-pot-the-black-bear-100k/
LDR:
smallbear does offer two versions of excellent LDRs for a Univibe:
http://smallbear-electronics.mybigcommerce.com/photocell-silonex-advanced-photonix-hi-dark-nsl-7532/
and, http://smallbear-electronics.mybigcommerce.com/photocell-silonex-advanced-photonix-hi-dark-to-5/
Both appear to be out of stock at this time. In their absence, I recommend any of these (I’ve used the 7532 in other builds
with good success).
http://smallbear-electronics.mybigcommerce.com/photocell-silonex-advanced-photonix-nsl-7532/
http://smallbear-electronics.mybigcommerce.com/photocell-silonex-advanced-photonix-nsl-7530/
or, the 9203: http://smallbear-electronics.mybigcommerce.com/photocells-cds-5mm-diameter/

BS250p Polarity Protection and Correction
I chose this method for the HB2 to take advantage of its very low voltage drop. However, I made a mistake in the layout-
the transistor orientation is shown incorrectly. Q15 must be ipped around to take full advantage of the BS250p. It will still
work the incorrect way but the transistor itself can be damaged by reverse polarity if left in its incorrect orientation (I nally
realized this when I fried my own transistor when I plugged the power in backwards).
Flip Q15 so that the half-rounded side faces up instead of down. The BS250p is slightly atter 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 jacks (http://smallbear-electronics.mybigcommerce.com/2-1-mm-plastic-
round-external-nut/) would be best. But, if you are like me and don’t have those the typical jack will work ne. To make
the internal nut jack work I cut the Ring tab off (it isn’t needed anyway) and gently bent the tab outward. This posed no
problems.
Notes

About Wah shells
Drilling Wah shells is very hard to do. They are generally made with heavy-duty die-cast and are much harder to drill than
most of our plunky aluminum enclosures. However, a stepped drill bit will do the job. Just go slow when drilling and use a
bit of force when needed.
Tools that will make the job go easier:
Stepped drill bit, Xacto knife, wire cutter and a deburring tool.
There is no drill diagram for the Harbinger Two. You need to work it out on you own. I used painter’s tape to mark out four
drill locations (two pots and two switches). I set them between the post and jack on the enclosure and spaced them about
1” apart on each row. I decided to stagger the top and bottom rows to make accessing the controls easier.
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 t
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 was able to get reasonably clean holes
Moral of the story: take your time and expect to do some real work here! It doesn’t have to be pretty.
Mounting
I left as much space as possible around the screw mounts to prevent any shorts from soldered pads to the enclosure. As
a bit of extra insurance, I recommend adding some kind of stand-off. What you use isn’t important so long as it creates a
barrier between the bottom of the PCB and screw posts. Tape, wadded up paper, whatever. I used a couple felts I had that
are for guitar strap buttons.

Light Shield
I do hope to be able to include a 3d printed light shield with this project. I may be able to do so by the time the boards start
shipping. But, in case it doesn’t work out here is an easy way to make one: 1) water bottle cap, 2) cover it in one layer of
painter’s tape, and 3) use a black Sharpie to mask out the tape.
To afx the light shield, I recommend the following: solder some buss wire the two the mounting holes on the PCB. Then
just bend them over and insert in the opposite side to keep the shield in place. You don’t need to solder all four positions.
In fact, don’t! You want to be able to remove the shield in case you need to visually inspect the lamp when making adjust-
ments. Exact measurements of the light shield below. Alternatively, you could solder one wire in each spot and then twist
them together over the top of the shield. Whatever works for you.
Lamp Calibration
The GAIN and OFFSET 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 nd the sweet spot for the vibe where you get the most lush and swirly sounds.
The OFFSET will set the lower oor for the lamp brightness. High amounts of offset result in a lamp that goes fully off at
the bottom of its sweep. Moderate and light offset means the lamp will pulse but never go fully dark. You will probably nd
yourself adjusting the GAIN and OFFSET a few times until you get the precise sound you want. I set my lamps to go fully
dark to moderate brightness and get great results with that.
Be careful when adjusting the trimmers so that the lamp does not blow. I have yet to do this in any build no matter where I
set the trimmers, but it is possible to do. Lastly, you should consider turning off your power supply or disconnecting the DC
jack when not in use. This will preserve the life of the lamp considerably.

Wiring
This diagram shows the HB2 wiring without an LED and is for a DPDT switch (since that is what many of the Crybaby
Wahs come with). You are welcome to use an LED indicator if you want, though. Just use a 3PDT and do the same wiring,
adding the LED anode and ground to the extra column. IOW, wire 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-pp/
3PDT: http://smallbear-electronics.mybigcommerce.com/alpha-sf17020f-0302-24r-l-3pdt-long-bushing/

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

Voltages
Q1 2n5089 Q2 2n5088 Q3 2n5088 Q4 2n5088 Q5 2n5088 IC1 LT1054
C 2.13 C 4.42 C 13.5 C 17.5 C 13.02 1 ~2.1v
B 1.45 B 2.13 B 4.4 B 5.53 B 5.25 2 4.94
E 1.03 E 1.57 E 3.8 E 5.17 E 4.51 3 0
40
Q6 2n5088 Q7 2n5088 Q8 2n5088 Q9 2n5088 Q10 2n5088 5 0
C 17.5 C 13 C 17.5 C 13 C 17.5 6 2.56
B 5.5 B 5.16 B 5.5 B 5.2 B 6.94 7 1.38
E 5.18 E 4.54 E 5.2 E 4.5 E 6.5 8 9.26
Q11 MPSA13 Q12 MPSA13 Q13 MPSA13 Q14 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 uctuations 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 speeds). Do not let it con-
cern you. These small uctuations will not negatively impact the overall result. What’s shown on the list above is the top measurement
for my 18v rail.
Current Draw: Between 50-60mA

Schematic