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Harbinger One help

Started by jingyjangy, April 18, 2020, 04:23:05 PM

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jingyjangy

I originally posted this in the General questions section but haven't gotten any responses yet and I would really like to put the finishing touch on a great sounding circuit.

Finally got around to building a Harbinger One circuit board from a couple of years ago. Everything works and I dialed in a great sound with the 2 trimmer adjustments. Problem is that even with the Intensity knob turned all the way up I'm only getting the depth of effect that I should be hearing at 50%.
Any suggestions would be greatly appreciated.

madbean

Is that across the board at all rate settings or just when the rate is set very slow?

jingyjangy

#2
It's at 50% intensity with the Intensity control maxed and speed set at a high rate. The intensity or depth lessens, as expected, further with lower speed settings. I pulled cap covering the light sensors and bulb and spray painted the inside a reflective silver. Originally I had it painted black. The change made no difference in performance.

madbean

#3
Things to look at:

1 - Further bulb adjustment. At 50% speed, your bulb should be bright, but not TOO bright and should go fully dark.
2 - LDR check: what did you use for the photocells.
3 - Voltages: Are you getting 15v in the LFO section?
4 - Parts check: double check that you have used the correct value for these resistors: R45, R48, R49, R50. A wrong value on any of those would throw off the intensity.

jingyjangy

Great Brian! Thanks so much! I'll check on all those items. :D

jingyjangy

Hi Brian,
It was #1. I adjusted Gain and Offset to what sounded best to my ears and didn't make sure the bulb was turning completely off. Dooh!
Disco! It now has the correct intensity range and sounds fantastic!

I used the Silonex 7532 and 7371 bulb as you suggested in the build doc.

I have another minor issue though that I hope you can give me some assistance with:
There is a loud "pop" when switching from Vintage to Modern and back again as well as a lesser "pop" when engaging the footswitch to turn on/off the effect.
Looking at the schemo I noticed that both C28 & C1 have 1M pulldown resistors but should I install another 1M resistor downstream of C29 to ground?
If so where would I attach the resistor? Which leg of C29 and which pin of switch? It's hard to tell what trace goes to which leg of C29 and what trace goes to which switch pin (ya know cause I have already boxed this baby).
You have to realize that I'm mostly just swatting at flies here.  ;D

As for the footswitch "pop" I'm guessing it might be from the off board LED which I have mounted on a 3pdt board from GPCB?

I'm running this at 18v DC and utilizing the filter PCB with a switch to allow use with either unregulated walwart or regulated 18v DC pedalboard power supply. I've omitted R54 on the filter PCB and using a jumper in its place.

Any help or further insight would be greatly appreciated!

Here are some pics:



jingyjangy

#6
Ok, solved the Vintage/Modern switch popping problem - I installed a 1M resistor across pin 1 pole 1 to pin 1 pole 2 then the another 1M between pin 3 pole 1 to pin 3 pole 2.
Dead quiet switching now.

Footswitch popping still a problem! Any suggestion?
Having the same issue with my Mangler build.