SOLVED Arachnid voltages normal? 1-3 work, 4-8 no wet.

CKLab

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Hi all.

Recently built the Arachnid. Analog signal is fine. All controls work, get expected wet signals on settings 1-3. On 4-8 I am only getting dry signal. When turning mix to all wet, there is nothing. Checked voltages to corresponding pins per setting and am only getting around 2.3-2.6v per pin when set to 4-8. Verified no issues with the rotary switch continuity, diodes all test expected fv. This sort of makes sense, as the 1n914's have a voltage drop around .6v. Fv-1 Chip was ordered pre-soldered from pedalpcb.

Ive built a few fv1 circuits all successful (until this one), hundreds of analog pedals and preamps, and I repair amps. I am just not sure why settings 4-8 would produce absolutely no wet signal. I would imagine 2.6v per pin is enough to trigger the settings, but am I mistaken? Per the schematic, only the settings where diodes are in the 3.3v path to pins 16-18 dont produce wet signals.

Thanks for any help/replies.
 
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Are you using an EEPROM or internal sounds? If you are using an EEPROM try temporarily setting it to the internal sounds and see if they all work. May be a problem with the software in the EEPROM and this will be a pretty good way to check that.
 
Are you using an EEPROM or internal sounds? If you are using an EEPROM try temporarily setting it to the internal sounds and see if they all work. May be a problem with the software in the EEPROM and this will be a pretty good way to check that.
Pcb was built to spec on pedalpcb datasheet. Came with 24lc32a chip. No mods or deviation from BOM.
 
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I think i realized what is going on. I ordered a Spacialist and the d3lay, and may ha e got tge 24lc32a's swapped, which is why there would only be 3 settings, and why im getting delays on a reverb pcb. FML.

Will update once i swap the ic's.
 
So do as I suggested above and temporarily change it to be using the internal programs. That will test to make sure the EEPROM is properly programmed. Pin 13 connects to a resistor which then connects to 3.3v. Lift the 3.3v end and connect to ground instead, then the internal programs will be in use and you can see if you get them all.

Edited - yes an EEPROM for a different project could definitely do it. Swap them first and if that doesn'r work then try my suggestion above.
 
Yeah, moral of the story, either work on 1 pcb at a time, or mark your ic's. Also, sockets are cool. Highly recommend them, because removing these without them is not the easiest of tasks.

Good news is, ive got reverb and d3lay now.
 
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