Product Review: Highly Liquid MIDI CPU
Company Website:
Price: $44.95 US (does not include MIDI In or Out port or power connector)
Rating: (5 out of 5)


Intro: Highly Liquid ( is a company with a wide variety of DIY MIDI products. What their website is lacking in glitz and fancy coding, it is chock-full of useful information, including a regularly updated user forum. When I first happened to make my way onto the site, I was confused about which one of their products I should use for a MIDI organ pedal conversion. An email to them yielded a quick, friendly and informative response, which included a link to their user forum. Their MIDI CPU was the product I was looking for, as well as some other things I would need for my project such as a MIDI port that needed to be wired to the MIDI CPU board.

My Experience: Although I have some experience soldering and fixing electronics, I was taken aback by the MIDI CPU board. It seemed so complex with all of its little holes, and I didn’t know where to start. My best bet was to actually read the directions, and to check out the user forum to see what potential issues I may run into.

Links to the hardware user manual on the MIDI CPU page pointed me to a PDF which was well illustrated and written, and I though it was interesting that it had been recently updated as well.

After procuring the tools and materials I needed, I was on my way. To build my pedal project I used:

The holes for attaching the wires are close to one another, and your soldering needs to be pretty accurate in order to make sure none of your wires touch. It took me a couple times on a few of the connectors to get this right. If two or more note’s wires touch you will get stuck notes, double notes or any other weirdness when you press a pedal. Be careful when you’re soldering! This is my only complaint about this product. I wish they provided or sold some kind of solderless connector for this kit. It would make it much easier for stoops like me to get the wires connected and my pedals working. 😉

Other than that, it was smooth sailing for the most part. Any other questions I had, I headed over to the forum and someone else had the same issue I did and it was resolved.

Using With MIDI Pedals: My project pedals work great and without issue. I left the 9V battery connection instead of trying out an AC adapter and it works fine. Just unplug the battery when you’re not using your pedals and the battery lasts a while.

Conclusion: The MIDI CPU is very well thought out and can be used in a variety of ways from a simple organ pedal project to amazing MIDI instruments such as full-on MIDI-fied organs, harps and other instruments. If you’re not the best solderer in the world, you may need help with the connections, or do a fair amount of practice before you tackle soldering the organ pedals’ wires to the MIDI CPU board. Check out their blog for projects, ideas and their other products.

Reviewed by Terry Goyette
This review © 2011