Monday, July 11, 2011

Better Pictures of the Not Quite Quad Slope

I just realized that I hadn't posted any decent pictures of the last module that I built, or the modular synthesizer as whole. Here are some slightly better (at least when they are embiggened) shots using our new little tripod. In the first one, you can really see the scratches in the faceplate. It's easy to forget how soft aluminum is.

This thing is a blast to use! Since I have completely failed to properly explain what it does, I've taken the following description from the Egres site:

"Here's a short list of things you can do with this module: AR transient generator, VC slew limiter, VC LFO (variable slope triangle and rectangular waveforms), VC audio oscillator, VC trigger delay, VC clock, VCLPF, VC pulse divider, Envelope Follower."

There are four identical generators on this panel, so it's pretty much two-thirds of a synthesizer by itself!

Here's a shot of my rig as it sits. Only two DIY modules right now (plus the big case), but that is changing, albeit slowly. The hole in the big case will be filled by a mixer module that I am working on now. There is a ton more in the queue, just need the dirty duo of time and money to get them done.

Unconditional Loathing in Providence, RI

Huge thanks to Breathmint/Matthew Rademan for these videos!

In this video, we witness the incredible patriotism and strong sense of civic duty for which Unconditional Loathing has long been known.

Unconditional Loathing @ Hive Archive 09.14.2001 from Breathmint on Vimeo.

Sunday, July 10, 2011

One of the greatest experimental performances of all time.

Unconditional Loathing's bastard offshoot Tripping on Falling perform during the subZERO experimental music festival at the Soap Factory in Minneapolis. Inspired by other acts they had seen performing at the Soap Factory, they ditched their instruments and came up with the highly conceptual piece of prepared music that you see here.

unknown @ subZERO 01.12.2002 from Breathmint on Vimeo.

Saturday, June 18, 2011

Not Quite Quad Slope

Like most modular synthesizer users and builders, I suffer from Serge envy. Thankfully for all of us, Ken Stone licensed some of Serge's designs to sell as CGS PCBs.

Here is my first module using these Serge designs:

Obviously, this module is influenced a bit by this lovely little beast. Once I panel up the Attenuverting Mixers I have, I will pretty much have the same capability. I am looking forward to checking out the other Serge PCBs, but first I have to panel up some of my backlog.

Build breakdown:

The front panel is 42 hp. It was the first panel that I ordered from Front Panel Express. I've since ordered another and have about ten designs in various states of completion that I'm working on in Front Panel Designer. They are a great company to deal with and I find it quite fun. Total cost of the panel with shipping was $105. I will share the FPD file if anyone is interested. If you are thinking of using them and are a first time customer, hit me up for a discount code.

The PCBs are attached to the panel with nylon standoffs that are JB Welded to the panel. I had originally planned on using a homemade bracket to mount them, but my bracket making skills are non-existent. The bracket I tried to make looked like a badger chewed on a license plate. The new panels I am working on all have holes for mounting standoffs directly to the panel. With some tidier wiring I could easily cut the module depth in half. The nice thing about this, is that I will be able to use use my DIY modules in most commercially available cases.

Here you can see the little power filtering daughter board that I modeled after the filtering (electro + ferrite) that Ken usually has on his boards.

When I fired it up for the first time, I noticed almost right away that the negative power rail was not being regulated properly. My surplus power supply now needs repair. Hopefully it wasn't doing this before when I had some of my other modules plugged in. Luckily, I have another power supply that I can try. This one is working fine, but I no longer have a +5V rail, so I have to remove that wiring. I also have to drill new mounting holes for the power supply since it is a different size.

Once the power was sorted, it was time to test the module. Only half of it worked fully right away. Not coincidentally, it was the second board that I stuffed. I was a bit clumsy and out of practice when I stuffed the first one and lifted a few pads, which broke continuity in few different parts of the circuit. While chasing these problems down I fried a 3900 chip. Man, I forgot how BAD the magic smoke smells when you let it out! The working pcb, schematic, and continuity tester helped me track down and repair the damaged traces. There is absolutely nothing wrong with CGS boards, they are just a little more delicate than some other PCBs. Build carefully and methodically and you will experience none of what I went through above. Also, don't blame the semiconductors (or any other parts) right away! They may need replacing in some cases, but make sure everything else is right first.

I had a great time testing the module last night. I did notice that my 256K BBD module doesn't seem to be working right. I'm not sure when that happened, but I guess I know what my next project is. (edit: was/is working fine, brain fart)

Welcome to the fun and exciting world of DIY!

Here's a picture of the project supervisor:

Saturday, May 28, 2011

Push It Real Good!

Part of my job at the electronics distributor I work for is to put together training presentations and booths that showcase a certain product or technology.

The product manager for one of the switch companies that we carry brought this fancy piezo button to my desk, and asked me to build something around it. Naturally, I chose to build a manual gate module for my modular.

The gate level adjusts the voltage out from 0-8V. This is run into one side of the button. The button is connected to the gate out jack. It is also connected to Ken Stone's gate to trigger converter and normalled to the CV input of Harry Bissell's Morph-Lag.

The button itself is kind of interesting. Like I said, it is a piezo switch. It will not stay on for as long as it is pushed. The contacts will "close" for up to a second, depending on how hard it is pushed.

More info about the button is available on this page.

It has been a fun exercise to put together, but I think a regular button or force-sensing resistor would be better for this application, especially considering the price. It looks pretty cool though, and it can withstand pressure washing!

One last thought...I would add an LED next time to show the state of the switch.

Tuesday, March 15, 2011

Ikea Rast Modular Synthesizer

It's done!

Cats are very into beefy terminal blocks.

All lit up!

So far I just have a few modules that I picked up used. Hopefully about half of the modules I put in this case will be kits that I put together or modules that I build from scratch.

Thursday, February 10, 2011

Saturday, January 29, 2011

You always remember your first


This is the first thing that I built from scratch. I had circuit bent/modified a few things in the past, but those were mostly built for live use so very little evidence of that era of tinkering remains. Anyway, this is a Rat replica built on stripboard based on the schematic at General Guitar Gadgets.
The bathroom spray paint booth in my last apartment was not one of my better ideas. Due to repeated exposure to delicious enamel vapors, I can now hear corn bread. Small price to pay when you consider the results.