Octagon with Expression Input

[Hexjibber]

Hi, this is my first post to this forum but thought it appropriate to share this build.

I will start by saying a big thanks to Madbean forum member bsoncini for their post on adding an expression pedal control to the Octagon, it was really clearly written as well as just being a great idea!

I've really enjoyed the project overall being my first delve into the realms of FV-1 and also PedalPCB, thankfully the board and instructions made it simple and easy so thanks for that!

The box is etched with NaOH (caustic soda/lye) with a few coats of clear for good measure. Here's the pics...

 

[zgrav]

nice design, and a clean build.

 

[Chuck D. Bones]

Beautiful! Nice clean build inside & out. Can you expound on the etching method, i.e. how do you transfer the pattern to the surface?

 

[the_grumpy_gnome]

This is beautiful. I love the original design. Expression pedal?! Can you please post the link? I'd like to add one to mine.

 

[geekmacdaddy]

Stunning work.

 

[Jbanks]

This is beautiful. I love the original design. Expression pedal?! Can you please post the link? I'd like to add one to mine.

Here’s bsonici’s original post on it.

Pedalpcb Octagon with expression jack

Pedalpcb Octagon with expression jack

www.madbeanpedals.com

I’ve also been looking for a couple weeks on line at adding EXP jack in general. Here’s some other links on the topic.

http://www.geofex.com/Article_Folders/xprnped.htm

How to include a CV/expression pedal input

How to include a CV/expression pedal input

www.madbeanpedals.com

 

[the_grumpy_gnome]

Here’s bsonici’s original post on it.

Pedalpcb Octagon with expression jack

Pedalpcb Octagon with expression jack

www.madbeanpedals.com

I’ve also been looking for a couple weeks on line at adding EXP jack in general. Here’s some other links on the topic.

http://www.geofex.com/Article_Folders/xprnped.htm

How to include a CV/expression pedal input

How to include a CV/expression pedal input

www.madbeanpedals.com

Thank you!

 

[Jbanks]

Always have to keep missing the pedals! Another fun addition is a 2knob job PCB. It adds a second pot for 2 different settings that can be switched between with a 3pdt. Great for those infinite feedback swells or a major gain boost.

 

[the_grumpy_gnome]

I'm interested in swinging the pitch up or down on the pitch-shifted delay.

 

[Jbanks]

I'm interested in swinging the pitch up or down on the pitch-shifted delay.

It does get weird sometimes transitioning between one pot and the other. Not exactly portamento style slides, but rougher.

 

[Hexjibber]

Thanks a lot everyone, I'm really pleased with this build overall

I did link to the original Madbean post in my post but the link colour on the forum is almost the same as the body text so makes it hard to see. I see it's been posted further up though so all good! Definitely worth a try if you're interested, just add an extra level of fun to it.

 

[Hexjibber]

Beautiful! Nice clean build inside & out. Can you expound on the etching method, i.e. how do you transfer the pattern to the surface?

Thanks!

I have a tutorial I did a while back on how I do etching, hopefully it may be of some use? I did it a good few years ago but my method hasn't changed at all in that time. Any questions though just give me a shout!

https://diy-guitar-effects.tumblr.com/etching

 

[ChrisSchwarzkopf]

Wow, thats pretty cool! does this work with the Arachnid (+custom EEPROM)?

 

[Hexjibber]

Wow, thats pretty cool! does this work with the Arachnid (+custom EEPROM)?

I would imagine so but did not come up with the mod myself, however in the original Madbean post referenced above someone had a similar question and it looks to be the case based on the fact the pots follow the same circuitry.

 

[phi1]

Wow, thats pretty cool! does this work with the Arachnid (+custom EEPROM)?

The octagon is actually the exact same thing as the arachnid, it just comes with the octagon eeprom. if you download the build docs, they are identical (they say arachnid on the top). The module8 is also identical, with the module8 eeprom. So, yeah this mod would work the same.

 

[ChrisSchwarzkopf]

Awesome! Cant wait to build that thing

 

[ChrisSchwarzkopf]

Hey, i am ready to build the thing and was wondering which jack i Need to buy for the expression input?

 

[K Pedals]

Hey, i am ready to build the thing and was wondering which jack i Need to buy for the expression input?

6.35mm 1/4" Stereo Insulated Switched Socket Jack Solder Lugs

Get It Fast - Same Day Shipping

www.taydaelectronics.com

 

[ChrisSchwarzkopf]

6.35mm 1/4" Stereo Insulated Switched Socket Jack Solder Lugs

Get It Fast - Same Day Shipping

www.taydaelectronics.com

Awesome, many thanks!

 

[ChrisSchwarzkopf]

Hey, I am still waiting for my Arachnid PCB which is currently enjoying it's time with German Customs for almost 4 weeks now /). In the meantime I spend my time designing the enclosure and everything and was also wondering how the rotary switch for the Expression Input actually works. I bought the switch shown in the picture and am unsure about the pin numbering. Can someone tell me which pins are A. B and C and which ones are 1 to 12?