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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 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 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.

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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