# Differences between new and old Arachnid boards



## p_wats (Mar 11, 2019)

I've got a half-finished Arachnid board, but have noticed there's a new 2019 version, with filtering improvements on the digital signal. I don't have the old PDF to compare to, but would it be possible to make some of those improvements on an older board (just the filtering, not the rotary switch)?


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## Robert (Mar 11, 2019)

The previous version docs are here:


			http://www.pedalpcb.com/docs/Arachnid.v1.pdf
		


You could replace all of your 220nF coupling caps with 1uF MLCC, put a 1K in series with C8, and a 2n2 to ground at pin 5 of IC5 and you'll be pretty close.


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## p_wats (Mar 11, 2019)

That's great. I don't have any issues with the first one I built (gigged with it a bunch too), but might try these with the one that's not boxed up yet. Thanks!


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## p_wats (Mar 14, 2019)

How difficult would it be to adapt the older board to work with a rotary switch (would it be worth the effort)? My band mate would prefer that for ease of selecting the effect.


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## Robert (Mar 14, 2019)

It'd be a little bit of work...   You'd have to use long pin pots to raise the board high enough for the rotary switch to fit underneath and wire up the diode matrix off-board.


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## p_wats (Mar 14, 2019)

Thanks. Yeah I was just perusing the build docs. Probably not worth the effort to retrofit. Might be an excuse to build another one of these days though.


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## zgrav (Mar 15, 2019)

easier to just build a new pedal and give the old one to a good friend.   the rotary switch is nicer, but not a game changer.


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