Double Arachnid mega pedal

p_wats

Well-known member
"I'll just build you a double Arachnid pedal", he said. "It will be easy", he said.

Last year I built an older Arachnid pedal with a custom EEPROM for my wife/band mate to use with her Nord Electro keyboard. She has really enjoyed it, but two things always stuck out to me:

  • The non-rotary mode knob of the older board resulted in her having issues finding the right patch between songs
  • 90% of the time she's got a delay running after her Arachnid no matter the patch
The first point is easy, as I can just build a new board with the 2019 revisions. While I'm at it, why not just build a second one with a delay, but maybe some other things too for extra fun? Thus, this beast was born:

double-arachnid-2017-04-17_01.jpg


I haven't finalized the patch selection yet. Right now it's a mix of an EEPROM from PedalPCB and another filled with random patches from SpinASM forums (there are some fun, weird ones out there).

Some hopefully useful additions include:
  • Toggle switch to select the order of the 2 PCBs
  • Send/return jacks for an effects loop (inserted after the 1st PCB, so less useful when the order is flipped)
  • Master bypass stomp (middle switch) that bypasses the entire thing (including effects loop)

    double-arachnid-2017-04-17_02.jpg

Many mistakes were made along the way, like:

  • Not checking the build doc and assuming all pot values were the same as the old board---it was a real pain to realize I'd used B100K for the mix pots on both well after I'd gotten to the boxing up stage.
  • Assuming the effects loop would be easy to insert, but forgetting that I'd also decided on the order switching toggle. This resulting in a lot of trial and error
  • Would probably prefer LEDs on the order switch toggle, but couldn't be bothered with the extra wiring

In any case, I tried it on guitar last night with my original Octagon in the effects loop and it sounded great:

double-arachnid-2017-04-17_03.jpg


Now to spend some time choosing patches!
 
I love the finish on your pedals... any color you can provide on the materials and technique?

Thanks! Nothing too special going on here. I usually just tape off the edges (sometimes I don't, depends on the colour of the enclosure) then spray a base colour or two, after which I splatter some other colours until I feel it's "done". Then I hit it with a few coats of clear gloss.
 
That is really nice. On my build I added a switch so I can either use the EEPROM or FV1 chip programs. I also added the clock board so I can adjust the clock speed and put a switch in so I can either use the clock if the board or the internal crystal
 
That is really nice. On my build I added a switch so I can either use the EEPROM or FV1 chip programs. I also added the clock board so I can adjust the clock speed and put a switch in so I can either use the clock if the board or the internal crystal

That's cool! I heard the internal programs weren't super great, so I left that out, but I'm curious about the clock. What are the benefits (I don't even know what it really does).
 
I like the internal programs, and it easy to set up. Just a SPST switch to ground from a resistor I do not have the schematic with me right now.

The clock, I first saw on the EQD Afternearth pedal. Pedal PCB does make a PCB for it. It just gives you another control option.
 
I like the internal programs, and it easy to set up. Just a SPST switch to ground from a resistor I do not have the schematic with me right now.

The clock, I first saw on the EQD Afternearth pedal. Pedal PCB does make a PCB for it. It just gives you another control option.

Thanks. I guess I'm unsure of what the clock control actually does. I've seen the pedalPCB board, but am not well versed enough to understand why I would use it.

I frightened. Fantastic work.

Thanks!
 
Thanks. I guess I'm unsure of what the clock control actually does. I've seen the pedalPCB board, but am not well versed enough to understand why I would use it.

The clock module speeds up or slows down the FV-1. It can drag out a reverb, or make it more dense.... It can increase the maximum time of a delay.... It makes a pitch shifter even more lo-fi than it already is (if you're into that sort of thing) ...
 
The clock module speeds up or slows down the FV-1. It can drag out a reverb, or make it more dense.... It can increase the maximum time of a delay.... It makes a pitch shifter even more lo-fi than it already is (if you're into that sort of thing) ...

Awesome, didn't notice you had a clock module. Looked for a build doc but couldn't find one. Are the three holes at the bottom right for a 9mm pot? Or is it just controlled by the trim?
 
The trim pot is the only control. I used a regular pot so I can adjust it. The other wires are for connections to the circuit. I do not remember right now what they are
 
Here is schematic for the clock board. So the three holes are for power, ground, and output
Yeah I realised that must have been the case right after I posted that reply haha! Cool, so you can use a pot instead of a trim? What type of pot did you use? Linear?
 
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