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Harbinger 1.5 Questions

Started by Caedarn, November 16, 2020, 05:32:26 PM

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Caedarn

Greetings all,
First, apologies in advance if I should have found this information elsewhere...
I'm working on a build of the Harbinger 1.5 and have a couple questions:

First, here's a link to the build doc: https://www.madbeanpedals.com/projects/_folders/FilterMod/pdf/HarbingerOneFive.pdf

1. 18V Operation:  I'm building the Harbinger to run on 18V.  I'm sure this is a dumb question, but I don't want to mess this up: I assume that the input power is supposed to connect to the pads marked 18V near the bottom of the PCB?  I checked against the schematic, and this seems right, but the pads are in an unusual spot which makes me wonder if I'm looking at this wrong.

2. LDRs:  I bought the NSL-7532 "high dark" LDRs from Small Bear - the same as those linked in the build document.  The problem is, I also bought - in the same order - four of the 'regular' NSL-7532 LDRs for another project.   I love Small Bear, but they don't mark their packaging, so I'm not sure which LDR is which.  I want to make sure to use the "High Dark" LDRs in the Harbinger.

I tried to measure the dark resistance of each LDR type, but am not sure I'm doing it right.  My DMM only goes to 60M ohm, so I measured the LDR in parallel with 40M resistance.  Both LDRs measure about 500M ohm 5 seconds after light removal.  One of the LDR types, though, seems to increase in resistance after light removal much faster than the other.  It also has a lower resistance when illuminated (~  500 ohm vs. 1k ohm)  Also, this LDR has a much tighter trace of Cad Sulphide material (that is, more 'loops') than the other type.

Any suggestions on how to tell the LDRs apart is appreciated.

Thanks in advance for the help!

danfrank

These are the hi dark ones from SB

Caedarn