Category Archives: Uncategorized

4 oscillator synth with an Atari Joystick

Yet another variation on the 4093 oscillator design, this one uses 4 directions of the stick for patching the outputs from off to on. The pitch of each oscillator is controlled by a knob and can be adjusted in realtime of course. The patching is not as easy as it seems because the resistors in the circuit can’t be switched in and out, instead I am basically switching the 1uF capacitors to the ground in order to engage the oscillators. In other words, since all the 1.0 uF capacitors in the circuit run to the ground, the joystick common was set to ground and the capacitor minus leads were soldered to the directional pins on the port. The fire button patches another 10uF capacitor in the circuit to one of the oscillators, creating a drastic pitch change. Quite a few shots of the insides and the building process are available on GetLofi gallery. The last image is also a video link, sounds good for such a simple circuit, especially once the delay kicks in.

D-Lab Multi-Plexer

A so called Multi-Plexer is currently up for grabs on eBay. Apparently the circuit was designed in the 70s and only a few units were sold recently. This sound sample is very Sci-Fi almost like a very deep tremolo effect with some slap back reverb. Apparently any sound source can be processed with this box. The auction description mentions an analog signal sent around in a circle and the result being a product of heavy manipulations. It seems like this can almost be a ring modulator with an LFO, but if anyone has info please do comment.

Thomas Henry article in Nuts and Volts

For those who do not already read the Nuts and Volts magazine, I suggest that now is a good time to start. Because the January issue featured an article by Thomas Henry who is a DIY synth guru with many articles on the matter. This article is a primer to analog synths with a basic guide to the essential elements like: VCAs, VCOs, VCFs, etc. There are only a couple of gripes that I can remember about this writeup. One of them was the 3 aspects of sound being: Frequency, Amplitude, and Harmonic content. I do believe that duration or the length of the sound is also an important aspect, making it the forth. However I am not even close to being an authority on synths like Thomas Henry, so I can be wrong on this. The second was an incorrect referencing of Wendy Carlos as W****r Carlos and pigeon holing Switched on Bach as the “Most Amazing” piece of music made with an analog synth, not leaving much room for exploration there. All in all felt that the article was well worth the price as a keep sake in my synth information collection. I would also suggest exploring the vast ftp resources of the Nuts and Volts website which contain previous Thomas Henry articles such as MIDI-to-Synth Interface and Building a tunable Noise generator. Enjoy.

4 Oscillator Opto-Theremin Gameboy 2

While on the subject of Gameboys here is more info on the latest opto-theremin I custom built. This time I was able to score a complete intact system with the screen protector. Of course the first step was to discard the guts, for later use 🙂 This version was kept as stock looking as possible. Existing buttons were drilled and glued in place to house photo resistors. Select and Start buttons have surface mount switches behind them for sound muting of the left and right channels. The headphone jack assembly was left intact and with the filter stage utilized. Dot Matrix Screen was replaced with a holographic sticker on the back side. Few more images can be also found in the Gallery section of the site and of course a quick video of the theremin being played is available for viewing. Enjoy.

GameBoy case + SK-8

Kaseo of Japan recently posted his SK-8 with a GameBoy break-out box to the Benders list. Looks clean and I dig the photos with nice professional shadows and such. The trigger buttons on the Gameboy are linked back with a DIN connector to the drum sample buttons on the SK-8 allowing for great solos, if needed. There are also glitch switches installed in the main unit and the sample mp3s suggest that those are effecting the drums. I can see the looks of chip-tune scene peoples’ when someone up on stage starts mashing buttons on a game boy while hearing sample sounds. Original Gameboy does make for a nice breakout box and synth enclosure, but I am torn by destroying something that survived over 2 decades of use. However the fact that there were over 120 Million sold pretty much says that there are plenty to go around. So check the eBay.
Here is the Video of the keyboard being played. Thanks. Kaseo.

Pitch Keyboard Mod for a Speak and Spell

Pete from CasperElectronics has sent me this diagram explaining how to get a keyboard interface attached to the Speak and Spell for controlling the pitch. From the drawing it looks like the keys are pressing on tiny buttons allowing for resistance specified by the trimmer pots to be substituted. One thing to note is the fact that this device was build for Danny Elfman, the composer of Simpsons and other well known themes.

2 year old SK-1

This is a relatively old and interesting looking model of a circuit bent Casio SK-1. The auction description mentions it being purchased two years ago, however the exact bend date is unknown. Not a very typical mod because I hardly ever see the numerical keypad installed on the SK-1s, usually patch bay and or toggles. This also features a joystick connecting to a DB-9 port on the front, my guess an off brand Atari spray painted. Its a shame that the person broke it during the move, or so it says. Never to less it would be interesting to see what this sells for.

1993 Circa V-Tech Catalog of toys

This brochure came with the VideoPainter I recently purchased. Interestingly enough there are a few models of things that I did not know about, like the Mickey Mouse Video Painter and a slew of talking Whiz Kid Toys. I hope someone finds this helpful and or fun to look at. Please note, images are fairly high-res, but the colors are off.

Getting back online

With the help of my guru friend I have recovered the old index. So thank god links are saved. Some changes will take place with the template soon. Until everything is setup, hang tite. Also I suppose any suggestions about the website features and the main page are welcome, during this process, so let me know. –CM

Page Updates

Emm, if the page does not look like it normaly does, please be patient. Someone somewhere screwed up my settings so things got lost. I’m getting everything back to normal very soon, with a few minor changes and updates.