# Percolation Station question



## Markus (Oct 24, 2020)

Hey, I'm sourcing some parts to do a Percolation Station, and C2 calls for a 50n cap.  I'm having a difficult time find one on my usual sites.  Would there be any major issues using a 47nf or 56nf instead?  

thanks in advance!


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## Barry (Oct 24, 2020)

I would sub the 47nf


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## K Pedals (Oct 24, 2020)

Yeah I just use the 47nf


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## Markus (Oct 24, 2020)

thanks!


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## Cucurbitam0schata (Oct 27, 2020)

47nf worked for my build!


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## Dan0h (Dec 19, 2020)

Bump. Going to build the perc this weekend. I’ve seen 47n and I’ve seen two 100s in series to get the 50n. Is the 3n difference a huge deal for this cap on the schematic? Anyone try both options to see? This looks like it might be a coupling Cap? If so the higher the value the more bass? Thanks forum dudes.


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## Chas Grant (Dec 19, 2020)

There is really no difference between 50n and 47n. The box film caps are normally 5% or 10% tolerance. So a 50n cap with a low value but still with in 5% is 47.5n. And if the 47n has a high value it could be 49.3n. If the caps are 10% then the overlap is even greater. And if you calculate the cut freq's 50n is 14.47Hz and 47n is 15.4. That is below the range of human hearing and 1Hz is nothing.

The pedal this is based on, is from the early 70's. Back then a 50n cap was a lot more common, now its a 47n. 

Just curious, what transistors are you using? Both the ones called for a a bit rare.


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## Dan0h (Dec 19, 2020)

Chas Grant said:


> There is really no difference between 50n and 47n. The box film caps are normally 5% or 10% tolerance. So a 50n cap with a low value but still with in 5% is 47.5n. And if the 47n has a high value it could be 49.3n. If the caps are 10% then the overlap is even greater. And if you calculate the cut freq's 50n is 14.47Hz and 47n is 15.4. That is below the range of human hearing and 1Hz is nothing.
> 
> The pedal this is based on, is from the early 70's. Back then a 50n cap was a lot more common, now its a 47n.
> 
> Just curious, what transistors are you using? Both the ones called for a a bit rare.


Dude, excellent knowledge share. Knowing that we are talking about sub 20hz I’m going stick with 47n instead of wasting two 100ns. I picked up an assortment of Ge Diodes and plan on socketing and trying different combos, mostly Russian. I picked up a real 2n404a & 2n3565 from small bear and got a couple equivalents to try as well. Excited to hear this thing.


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## Chas Grant (Dec 19, 2020)

Dan0h said:


> Dude, excellent knowledge share. Knowing that we are talking about sub 20hz I’m going stick with 47n instead of wasting two 100ns. I picked up an assortment of Ge Diodes and plan on socketing and trying different combos, mostly Russian. I picked up a real 2n404a & 2n3565 from small bear and got a couple equivalents to try as well. Excited to hear this thing.


That's OUSTANDING! One of my favorite things is to build the classic circuits, using as many as the correct parts as possible.  Let me know how this sounds. I recently came across a bunch of old caps and there was one 50n cap in the bag. Its an old ceramic cap but its built sturdy so I'm looking for a good effect to throw it in.


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