As an avid electronics enthusiast along with being a guitar player, I have always loved tinkering with new sounds and making changes to pedal designs.  After a lot of fighting with messy work areas (if you work with electronics, you know exactly what I am talking about!) I thought there had to be a better way.  I made a few of these prototype breadboards with integrated input/output jacks, a 9V DC input as well as a bypass switch to help me clean up my workspace and designs.  Well, after a few modifications to my original design (which I still use by the way!) I decide if I like these, other pedal builders would like them too. 

I make these with my 3D printer and then use off the shelf parts to assemble them into a complete unit.  The 1/4" mono jacks on the back connect as the input from your guitar and output to your amp.  I put a true bypass toggle switch that allows you to either play through your test design or run a dry signal out.  The LED lights up when you are running through your pedal design, then turns off when you are in 'dry' bypass mode.  In the front there are 4- four pin connectors to tap into for the input, output, positive and negative that tie into your breadboard.  I include 10 jumper wires to get you started.  

Note: Color may vary.  Typically they are black but sometimes I do them in different colors depending on the amount of filament I have at the time I print them.  

I make two sizes of these, the Extra-large which is this listing which has 2490 connection holes, and the large which has 1660 connection holes.  The large give you a lot of real estate to make large pedal designs, or even make different 'building blocks' to mix and match.  The medium is a little smaller and is plenty large for most designs.

Includes the breadboard and 10 jumper wires.  Required a 9V DC (center negative) power supply.  This is the same size and polarity of a typical pedal power supply.