Category Archives: How To…

DOD Guitar Pedal Replacement Battery Cover For Sale Now

IMG_0443.JPGHere at GetLoFi we have been working in some projects that are not exactly circuit bent but were certainly inspired by circuit bending. One such project that has been in the works for close to a year now is a replacement battery cover for DOD vintage guitar effects pedals. The need for this projects arose from having a personal collection of various DOD pedals which had 1 thing in common, they were missing the 9 volt battery cover. Because they came from as-is auctions on eBay and in most cases cost me less than $20 shipped, the battery cover was certainly missing. So what to do? I certainly wanted to get most value out of the pedals from resale however an alternative replacement cover did not exist yet. I was lucky enough to strike a friendship with a youtube user who had similar manufacturing and wild idea interests as me and eventually learned of his forays into injections molding, this was a perfect project. At a glance these lids seem like a strait forward piece of plastic however it was not until about 4 iterations of the aluminum mold that we were able to dial in size and complexity of all the parts involved.

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At last however the project is virtually finished and the molds are sitting safely on the shelf awaiting a next batch. So order up and make us proud. Head over to dodbatterycover.com and getlofi.com/shop see and purchase fruits of our labors.

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As you can see several parts were tried out until the final design was born.

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Various covers through out the process, 5 different variations were made and then later tuned up.

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There was even one with GetLoFi logo on it, but I decided that if these were going to be in stores perhaps not the best idea to plaster my brand all over it.

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The final Hinge Style cover can also be purchased as a kit and assembled with nothing more than a few drops of Acetone and a Q-Tip. My first Instructable is located right here: http://www.instructables.com/id/How-To-Assemble-DOD-Guitar-Pedal-Battery-Cover-Rep/

 

 

My Getlofi LTC 1799 Gameboy Mod for WOFF!

by Austin
I’ve had a Gameboy sitting around for a bit now, a nice, clean one I picked up at St. Vincent De Paul’s for $5.  I wanted to add an LTC module and Pro Sound Mod to the Gameboy as a gift for my friend, Gary, who is one half of the team that brings you the Podcast Watch Out For Fireballs.  I found the soldering to be simple, but met some other unexpected challenges – I hope seeing my process will help you readers out there who have a Gameboy slated for modding to better plan your project.
To get started, I had to open up the Gameboy, which ended up taking much longer than I anticipated.  When I turned it over to get at the screws, I noticed it had proprietary 3-notch screws keeping the halves together.  I would recommend either investing in a screwdriver that would fit these or you can do what I ended up doing:  drilling off the screw heads at the drill press.  Drill carefully and only as far as you must;  the screws connect to plastic posts in the front half of the Gameboy and only one screw was still long enough for me to grab it after drilling.  I backed it out with a pair of needle-nose pliers, then ground down the remaining plastic posts just enough to grab and twist out the other screw shafts.  This was tedious, but had I bit the bullet and gone straight to drilling it would have been faster.  Luckily, the Gameboy still fit together fine, even with the shortened posts.
One thing I would recommend is considering Getlofi’s specialty Gameboy LTC Pitch Modification kit which includes a space-conscious on-off switch.  That said, the inside of the Gameboy is what I refer to as a “Space Nightmare.”  No, Kthulu isn’t in there, it’s just a tight fit for putting more components inside.  There is barely a 1/2″ wide column of space to work with going up half the right side from the bottom to use.
I wanted to use a push-on/push-off latching button in the front to connect/disconnect the LTC signal for aesthetics/usability, which was the first thing I decided to tackle.  Hindsight is 20/20 and I would recommend leaving this operation for last, as it is the only thing aside from the screen ribbon cable that connects the two halves of the Gameboy, once open.  Because I did it first, I had to contend with the button wires during the rest of my wiring, which was annoying.  The ribbon cable can be carefully removed by hand.  Be gentle, because damaging the leads will affect the display.  I also had to route out some of the battery compartment for the button to be able to fit in place.  If you choose to mount the button like I did, be careful when widening your pilot hole in the front of the Gameboy, I ended up chipping the Gameboy’s case where it is slit for the (removed) speaker – opt for using your Dremel rather than your tapered reamer to widen your pilot hole.
Getting the LTC’s potentiometer to fit inside was not too hard, though I did have to grind away the side of one of the plastic screw posts for space.  The LTC module itself tucks nicely under the bottom half’s circuit board.  I decided to attach wires to the LTC board instead of directly attaching it to the potentiometer.  The LTC board tucks under the Gameboy’s board neatly, loose but blocked in place by the potentiometer.  I ran wires in parallel to the potentiometer leads to the RCA jack at the bottom to control the LTC remotely.  I did have to trim off a little bit of the RCA jack’s tip lug for the fit.  I would recommend gluing the RCA jack in place inside, they can tend to twist around.
When it came time to put the Gameboy back together, I noticed that there were threaded metal nuts embedded in the screw-holes in the back half of the Gameboy.  This is so that only screws with the correct threads can fit. I tried to find properly threaded screws at my local hardware store, but that didn’t work out – they are super small.  I carefully drilled these nuts out with a slightly larger drillbit, taking care not to damage the circuit board, then screwed the Gameboy back together using screws from my tiny screw collection. Once again my jar of tiny screws comes to the rescue – junk toys can end up yielding a lot of these helpful little guys and other handy components.  Skip the hardware store and go to the drill press, they won’t have the right screws any way.
Lastly I assembled a remote controller for the LTC in a bottle-cap.  I added a latching on/off switch for the Photocell and two body contacts, both of which are wired in parallel with the on-board potentiometer using an RCA cable to fit the jack I installed.   I ended up with a messy hot-glue job at first, because I had forgotten I had turned my glue gun to low.  I redid the hot glue finish by gingerly zapping it with a heat gun, taking care not to melt the cap – nice and smooth.
It came together over a couple of days, though there was a lot of sitting and thinking before acting.  Hasty screw-drilling can be a set-back some times, but I would highly recommend it in the case of the Gameboy.  Also, speaking of drilling, make sure you clean all of the metal and plastic dust out of your Gameboy before reassembling, especially from behind the screen.  I did so by carefully removing the front circuit board and using a little canned air.  Also, protect your screen from getting scratched while you work by putting a piece of tape or a sticky note over the front it – something I forgot to do.
I hope these tips helped you plan your project, I know I learned a few things in making it.  To help keep you entertained while soldering up your Gameboy, why not check out Watch Out For FireballsWOFF is my friend Gary’s podcast which reviews retro video games for your amusement!  In other news, CMKT 4 is about to head out West for the Bay Area Maker Faire with a string of workshops, stay tuned for details!

GetLoFi 4093 Quad Oscillator Pedal and Kit

At one point or another every aspiring electronic enthusiast builds a Schmitt trigger oscillator to generate audio frequencies. For me it was no exception and that’s what fueled my interest in electronic music instruments. In 2006 this GetLoFi post was published detailing a simple oscillator circuit that worked fairly well as a rough starting point. Today the same basic idea is available in kit form and as a hand-built pedal from GetLoFi.com/shop for everyone to enjoy the crunchy square wave oscillation and modulations.

Surely anyone can build a similar circuit with a few Radio Shack components however the are some nuances for making a great sounding oscillator. First off tame that output if you are using a 9 volt battery to power this circuit, the hot output will be too distorted and dangerous for the amplifier. To make things quieter simply add an electrolytic capacitor 1uF or greater with the – side towards the output and a 1K resistor following in the series. Then bridge the output pins from Ground to the Tip with a 100 ohm resistor. This attenuates the output by dumping some of the signal towards the ground.

The second tip is ALWAYS use sockets for your IC chips, even if the chip is not expensive or you are in a hurry to finish a project. This will help down the line when for some reason the IC stops working be it from overheating, a short, or applying the power to the unit backwards. It is a million times easier to fix something by simply popping the IC out and replacing it with a new one, then going through a de-soldering nightmare, especially if you are working on a Through-hole board. Virtually all GetLoFi Kits are surface-mount making it easier to correct an error and replace a component.

The final tip for building oscillators and other devices that run off 9 volts is include a Boss-style DC Jack. It means that the DC jack is 2.1 mm with Tip ( – ) negative wiring. Please note that the assembled 4093 Quad Oscillator Pedals do have this feature. Having a DC jack liberates your pedal more in conjunction with the internal battery. Surely you can still use the 9 Volt clip, however now there is no worries about the device dying in the middle of the show or a recording session. There will be no changes in pitch and operation from the sagging battery voltage. Also no need to remove the backing in order to swap a $3 battery when the power switch gets accidentally gets left on. As an added bonus the power jack can be used as a Gate of sorts for the device. With a 555 or the LoFi Sequencer acting a power source to drive the 9 volt entire circuit, so by connecting their outputs to a DC jack you can instantly add a pulsing feature.

In closing we hope that all those tips help you when putting together an electronic device made to last. For those who do not feel comfortable searching around for all the correct parts and stressing over confusing schematics, please try out one of our simple to assemble Kits. They include circuit boards and all the parts needed as well as step by step photo assembly assistance. The Quad Oscillator pedals are also now available from the GetLoFi.com/shop. Enjoy.

Pitch Control with LTC1799 for Yamaha VSS-30

One of our readers sent in a diagram for circuit bending a VSS-30.

“I just finished modding my Yamaha VSS-30 with a LTC1799 Precision Oscillator from www.getlofi.com/precision. Since I couldn’t find a picture of the correct pins to wire it to online, I had to figure it out myself. I’m posting this here so that anyone looking for it in the future can find it.

Soldering to the pin that I have the white wire going to will make the LTC1799 affect both the preset sounds, and the sampled ones. I didn’t need to remove the oscillator from the board, so this mod is pretty easy to do.”

Adding Touch Sensitivity To Projects

by spunkytoofers


Fortune Cookies: Series of chaotic speech synths based on the Vtech Talking Whiz Kid circuit. Each one in the series is unique and an exploration into different interfaces. The Whiz Kid when circuit bent is what I consider bends under the category of glitch stream. A device is bent into streaming a series of endless/random flow of glitches and further bends will determine the course of it’s flow or interruption of flow.

In this particular version I’m using touch sensitivity to interact with the glitch streams. It’s a pretty simple concept you can apply to any touch based project so long as your components are metal to the touch and electrically isolated from the enclosure you’re using. This works for switches but this can also work very well for momentary buttons. If you find the right connections you can add an expressive touch sensitivity to your trigger and switches.

Strip a good amount of stranded wire and wrap the wire around the component’s base on the underside of the non conductive enclosure, then tighten the component down. If components have hardware such as washers it’s pretty easy just to thread the wire in between the washer and component (given it is thin yet sturdy enough) and then just tighten the component down to the enclosure making sure the wire is making contact with the metal casing of your component. Use a multimeter or other means to check the continuity of your your wire to the touchable part of your component.