News

Hand Clap Pedal

Details: Published on Sunday, 17 March 2013 16:18

This is my first attempt at painting a custom pedal. Up until now, I have always used inkjet printed vinyl stickers on my custom pedals.

The pedal is built around the hexinverter.net NeinOhNein Clap circuit board, a clone of the clap sound from the TR-909. Hex Inverter has some great products including a whole series of 909 clone circuit boards.

The board is intended to be used in a modular synthesizer which supplies +/-12 or +/-15 volts. I wanted to use a standard 9V pedal power supply, so I did some testing. The circuit does not work well with +/-4.5 volts, so a virtual ground circuit was out. By not working well, I mean it had a hiss. I have noticed that with other circuits when trying to run them with very low voltages. So, I used a TC1044S charge pump chip to provide the -9V. I added an LED illuminated push-on/push-off power switch, a big button to trigger the clap sound, and a trigger input jack so the sound can be triggered by a drum machine or sequencer or whatever. I wired a diode in series from the jack and from the button to keep the voltage from either source from flowing into the other.

Building the electronics was relatively straightforward. The real project for me was making the enclosure look good!

Under Re-Construction

Details: Published on Sunday, 17 March 2013 05:35

This website runs on the Joomla content management system. It was running on an older release of version 1.5, so I dutifully upgraded it the the most recent release, 1.5.26. Two days later, the site was hacked.

Now it is running on the latest release of Joomla 2.5. I was able to migrate all the articles and users over, but not the look. Which is why it looks so plain right now. It will get spruced-up over the next few days, but it will look different than it used to - better I hope.

The Effeutron Autonomous Noise Music Machine

Details: Published on Thursday, 06 September 2012 18:43

The Effeutron is a device I created specifically for the Wall Only Fest. It is an autonomous noise wall music generating machine. It has eight independent oscillators each with its own LFO and variable period gate, using four CD40106 chips. The oscillators themselves are gated in sequence by the CD4040 divider chip. A CD4049 chip provides a clock for the divider as well as a tube-sound fuzz effect. It runs through all 255 combinations of the oscillators, then stops.

It really doesn't have to run hands-off. There are 50 parameters that can be adjusted while it is playing. The amount of fuzz and the speed of the clock can be adjusted. Each of the oscillator blocks has six trimmer potentiometers to modify the sound. There are a lot of sonic possibilities here!

It was a fun project to build, but not being a noise musician, I probably won't use it again. If you are interested in owning the one-and-only Effeutron, feel free to contact me and make an offer.

Update: The Effeutron is sold. Congratulations to Nicholas in Australia. Have fun with it!

Anatomy of a Drum Machine

Details: Published on Tuesday, 31 July 2012 18:42

This is the story of the design and development of the Delptronics LDB-1 Analog Drum Machine with a focus on the technical details.

I had been studying analog drum circuits for about a year, including both classic drum machines and more modern drum circuits and modules. In January of 2012, having just finished several projects, I felt it was time to dive into building some drum circuits. My goal was to build a small, low cost drum machine, and I knew that the first step was to get the sounds right. I breadboarded every drum circuit I could find and compared the results with samples from the classic drum machines, particularly the venerable Roland TR-808. I worked on it full time for two weeks. By the end of that time, I had the circuits refined and tuned and sounding just the way I wanted them.

The one sound I could not get quite right was a rim-shot. The closest I could get was a woodblock. I figured it was time to build a prototype and I would get back to the rim-shot sound later. To my surprise, I got a lot of compliments on the woodblock sound, so I kept it as is.

I then went through the process of choosing a microcontroller to be the brains of the drum machine. That process is described in more detail below. I worked out the basic code for a microcontroller triggering the drums and built the prototype. Having worked out the bugs, I designed a printed circuit board and built several devices.

The most time-consuming step in the development of the LDB-1 was to program all of the features. I went through many iterations of the code to get every feature of a classic drum machine into the LDB-1 with an easy to use interface. A three month long beta test cycle really paid off.

When development was complete, there was still a ton of work needed before it could go to market, tasks like writing the user manual, sourcing the components, assembly, the design and production of the enclosure, and so on.

Original Prototype	Final Production Model

The Circuits

The rest of this article is a description of the LDB-1 circuits. The information presented below should provide you with all of the information that you need to understand and even modify the LDB-1. If you have specific questions not answered by this article, please feel free to contact me. As you read the article, follow along with the LDB-1 Schematic .

Giant Little Drummer Boy

Details: Published on Wednesday, 18 July 2012 18:29

I build a giant version of the Delptronics LDB-1 “Little Drummer Boy” analog drum machine kit.
It is pictured below next to the standard kit to show the scale.

The actual assembly was not difficult. Of course, when I assembled the kit, I skipped all of the parts that would eventually be panel mounted. Instead of getting all new panel mount jacks, I could have positioned the PCB at the back edge of the enclosure and drilled holes for the board-mounted jacks to come through. However, lining up the holes is such a hassle that panel mount parts are just easier. Once the parts were soldered on the PCB, I soldered wires for all the jacks, buttons, LEDs, etc to the board, then to the panel mounted parts.

Here is a color-coded diagram of the LDB-1 PCB that will be very helpful if you want to build it with externally mounted parts. The pads that you need to connect to are green. Some pads are gray to indicate that there is no panel connection, just for extra clarity. I colored the ground pads blue so you know you can wire them together on the panel. Keep in mind that this is a bi-polar circuit, so the negative power connection is V-, not ground.

All told, it was about $100 in extra parts, plus $140 for the kit, plus about eight hours of work. The result is well worth it. I now have the biggest Little Drummer Boy on the planet! Of course, being the inventor of the LDB-1, I had a head start, but I would love to see what other people do with the kit.

These were the extra parts I needed, with links for some of the less generic items:

Passive Matrix Mixer

Details: Published on Thursday, 21 June 2012 00:09

I recently built a 5x5 passive matrix mixer. A passive matrix mixer is one that contains no active components, that is, no amplifiers, buffers, or anything that uses electricity. The signals are mixed through resistors, and are attenuated by potentiometers. I also included switches so that the level can be set with the pot, then turned on and off with the flip of a switch. One thing to keep in mind about a passive mixer is that it works best if the signals are fairly hot. Line level signals will work, but will not give you much headroom in the volume department.

This is what the big boy looks like:

Experimental Garage Sale 5

Details: Published on Tuesday, 22 May 2012 18:15

Saturday, June 9, 2012
Noon - 6pm

Experimental Sound Studio
5925 North Ravenswood Ave.
Chicago, IL 60660
[map]

The Fifth Annual Experimental Garage Sale will feature Circuit Bent Instruments, Un-Bent Gear, Parts, Vintage Components, Custom lamps, Kits, Art and a Raffle.

A dozen vendors from around the country will be there - including Mickey Delp / Delptronics!

More info at GetLoFi.com

Mickey Delp dot com