# ADHD just True Bypass?



## irvmuller (Jul 29, 2020)

So, I'm not much a fan of buffered bypass and am just wanting to go true bypass for the ADHD. I plan to not use the DPDT and just connect the spots on the PCB. However, I need to know if True Bypass is in the up or down position. Can someone tell me?


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## K Pedals (Jul 29, 2020)

true bypass is in the up position 
So you’d need to jumper the bottom two pads...


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## K Pedals (Jul 29, 2020)

You can also leave out C13, C14, C18, Q6, R5, R31 R35 and R37 since those parts are only used for buffered bypass.


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## irvmuller (Jul 29, 2020)

K Pedals said:


> You can also leave out C13, C14, C18, Q6, R5, R31 R35 and R37 since those parts are only used for buffered bypass.



Dude, you gave me what I wanted and more! Thank you so much. You’re the man.


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## irvmuller (Jul 29, 2020)

I'm planning to use the ADHD on bass and so may even cut out the switch for HP/LP. I'm assuming the LP option on the switch would be down which means I would connect the top two pads. 

*What resistors or caps could I cut out by doing that?* (If any) I tried figuring out myself from what you told me previously but couldn't figure out why we would keep R32 & 33 from before, so clearly, I've got a ways to go until I have an understanding like you about this stuff.


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## K Pedals (Jul 29, 2020)

This is the buffer section 
I wouldn’t leave the hp/lp (high peak & low peak) out of the circuit if I were you... a lot of people thinks that stands for high pass and low pass but it’s not a filter switch...


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## irvmuller (Jul 29, 2020)

You’re absolutely right about it not just being a low pass and high pass. Definitely holding on to it.

I noticed that you didn’t mention taking out R32 and R33. Why would we keep those? Just asking for understanding?


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## K Pedals (Jul 29, 2020)

It’s part of the buffer


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## irvmuller (Jul 29, 2020)

So I can go ahead and keep out R32 and R33 as well?


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## Chuck D. Bones (Jul 29, 2020)

That's right, leave R32 & R33 out.  With Q6 gone, there's nothing for R32 & R33 to do...


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## Chuck D. Bones (Jul 29, 2020)

K Pedals said:


> This is the buffer section
> I wouldn’t leave the hp/lp (high peak & low peak) out of the circuit if I were you... a lot of people thinks that stands for high pass and low pass but it’s not a filter switch...


C8, R11 & R12 set the low-pass cutoff freq.  The TONE control sets how much cut you get.  It's called a shelving tone control because the amount of cut is limited by R14 & the TONE pot.  The HP/LP switch also affect the overall volume, but that's just a by-product.


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## manfesto (Jul 29, 2020)

As an alternative, isn’t the Blue Waffle basically the ADHD without the buffer?


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## irvmuller (Jul 30, 2020)

manfesto said:


> As an alternative, isn’t the Blue Waffle basically the ADHD without the buffer?



Oh nice! I compared both and parts and the schematics do appear to be pretty similar. However, I'm not sure how the Blue Waffle will run on bass (which is what I play) but I'm familiar with how the ADHD/OCD will run on bass. I'm thinking the Blue Waffle is definitely one to try down the road.


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## manfesto (Jul 30, 2020)

irvmuller said:


> Oh nice! I compared both and parts and the schematics do appear to be pretty similar. However, I'm not sure how the Blue Waffle will run on bass (which is what I play) but I'm familiar with how the ADHD/OCD will run on bass. I'm thinking the Blue Waffle is definitely one to try down the road.



The ADHD is based on the OCD, the Blue Waffle is based on a pedal that’s a known chinese clone of the OCD (Long story - a guy was buying Joyo OCD clones and repainting them to sell at boutique prices - I’m assuming PedalPCB made the board for it as a laugh), can’t imagine why one would work where the other doesn’t.


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## irvmuller (Jul 30, 2020)

I may consider it. Especially since the ADHD is on back order.


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## manfesto (Jul 30, 2020)

Looking at the schematics, it'd be pretty straightforward to mod the Blue Waffle to be essentially a true-bypass ADHD.

EDIT: took a second look and missed a few

R2 - 3K3
R3 - 1M
R4 - omit
R10 - 22K
R11 - 33K
R12 - omit
R13 - omit

C2 - 100n
C7 - 1u
C8 - 22n

OD pot - A1M
T pot - B10K
V pot - A100K
D1 - Jumper (or leave it in, apparently some versions of the OCD had this diode)


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## irvmuller (Jul 30, 2020)

So, I've run into a hiccup. Is there any way of knowing which caps go with which spots? So, for example, if I'm using 1u on C7 but don't want to install the same part on C18, how do I tell them apart. That info isn't in the docs. Is that mapped out anywhere???


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## manfesto (Jul 30, 2020)

First page of the build docs usually has the PCB layout with part numbers instead of values


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## irvmuller (Jul 30, 2020)

Not on the ADHD...


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## Robert (Jul 30, 2020)

irvmuller said:


> Not on the ADHD...



Now it does.   

(redownload it)


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## irvmuller (Jul 30, 2020)

Robert said:


> Now it does.
> 
> (redownload it)



Total boss move! Thanks!


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## Chuck D. Bones (Jul 30, 2020)

Right on!  Us modders need the ref des on the assy diagram since we're gonna pretty much ignore the part values.


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