It’s Alive!: Build Your Own Electronic Kit

The moon ducks behind gathering clouds, plunging the earth into the darkest night. You wake in a sweat, the urge to attack the kit dominating your thoughts. But … curses! What about the neighbors? It sure would be sweet to have an electronic drum set at a moment like this. You muse over the flexibility of such a creation: the seemingly endless possibilities; the awesome variety of sounds; the ability to thunder while barely making audible noise; and the option to crank it up when the situation warrants it.

Electronic drum kits offer plenty of advantages. They’re acoustically quiet, usually fairly compact, and can trigger a wide variety of sounds, even loops, depending on the features offered by the drum module. There are many manufactured selections, but these can cost a pretty penny. So here’s an idea: why not build one yourself? A few parts here, a few items there, a little elbow grease, a couple of tools, a modicum of ingenuity, and of course, a good brain. Well, Dr. Frankenstein, let’s get started digging up what you’ll need so you can get started on creating your own personal monster.

What You’ll Need

A Brain

Drums:
Old Shells
Rototoms, a Practice Pad Kit (Remo Or Gibralter), or Homemade Pads

Cymbals
Plastic Practice Cymbals, Rubber Pads, or Inexpensive Brass Cymbals

Rack
Use a Prefab Mounting System or PVC Piping with Couplers and Joints, plus Hardware/Clamps to bolt it together

Triggers
Piezo Elements (with two soldered leads)
Foam Cones

Tools
Soldering Iron
Tin Snips
Drill with bits capable of drilling wood and metal
Screwdriver (Flathead and Phillips head)
Exacto Knife or Razor Blade
Hacksaw
Wire Strippers

(Some other nice tools to have, but not absolutely necessary: Table Saw, Drill Press, Dremel)

Other Stuff
Sheet Metal (various, but bronze is best)
Metal Bar
Foam Rubber Sheets (like mouse pad material)
Sorbothane
3/8" Auto Tubing
Wood: a couple of 2x4 pieces
L-Brackets
Screws and Nuts to secure the brackets
T-Bolts and T-Nuts for mounting the piezos to crossbeams
1/4" TS and/or TRS Jacks
Instrument Cable (hot/shield)
Balanced Cable (hot/cold/shield)
Solder
Silicone, Hot Glue, or Rubber Cement
Super Glue
Gaffer Tape or Duct Tape

Dig The Basics

Before you begin, you’ll need to determine your preferred playing surface(s), an appropriate module, a mounting system, and a practical triggering method for your purposes. Your approach will depend on how much you’re willing to roll out and how much time you want to spend on this labor of love. Then you’ll need to find and purchase the parts and make sure you have the right tools for the job.

One of my students, let’s call him “Jake,” recently embarked on a mission to build his own electronic kit, so I tracked his quest to help illustrate the process better. Jake’s vision incorporated a number of techniques for building the components of an electronic kit, so I’ve included details of his progress, in addition to offering alternative angles to creating an electronic kit that’s right for you.

Gathering Body Parts

Playing surfaces abound: from mesh heads on drum shells and Rototoms, to rubber pads, to real-feel Mylar-head practice pads like the ones made by Remo. Muted acoustic drums with regular heads can also be fitted with pickups. If you’re feeling really creative, you can make your own pads. Plastic practice cymbals are an excellent option for making e-cymbals and have realistic action, though you could also use rubber pads, or even inexpensive acoustic cymbals muted with rubber padding adhered to their surfaces.

Jake chose to go with mesh heads fitted into an old set of Rototoms, a funky old 12" tom for the kick drum, and a beat-up metal snare. He bought some bass drum spurs for the tom and a set of Pintech plastic practice cymbals. For the hi-hat, he layered a 1/2"-thick disc of wood with a rubber surface as an interim measure until he gets the stuff to make a hi-hat with a more realistic response and feel. He then mounted the whole lot to an old Yamaha drum rack. Other options besides a pre-made rack include making your own out of PVC or metal piping, couplers, and joints; welding one together out of metal piping or rebar; or using traditional hardware if you opt for a trigger-retrofitted acoustic setup.

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The Nervous System

Triggers are the nerves of the kit. They sense the impact of the stick or beater and send a signal to the drum brain for processing. The simplest trigger can be created from a piezo transducer, which is available (encased in plastic) at RadioShack, unsheathed from an electronics vendor such as Mouser, or from an online electronic drum resource. The piezo pickups usually have a red wire soldered to the central crystal, and a black wire soldered to the outer metallic ring, but if the piezo is not yet terminated, you’ll have to solder leads onto them yourself with 20awg wire. The red and black leads get soldered to either the tip and sleeve of a 1/4" jack, or directly to the hot conductor and shield of a typical instrument cable that plugs into the brain’s trigger inputs.

Considerations when setting up the triggers include: increasing surface space for even response, isolation from extraneous vibrations to prevent double or false triggering, and protection of the delicate piezo element. The approach you take depends on the playing surface. Since Jake opted for mesh heads on Rototoms and old drum shells, he adopted the Roland approach of mounting the piezos to a metal surface and sticking foam cones on top of them. The foam cones get positioned so that they press against the underside of mesh heads to pick up the stick attack.

If you’re retrofitting a rubber pad or Remo practice kit setup, gluing the piezo to a thin, larger diameter flat disc increases the response area of the surface and effectively transmits the vibration of a stick hit to the pickup more evenly at a wider radius. Thin sheet metal cut to size is common, but some folks have used old CDs and even plastic plates quite successfully. The delicate element must then be isolated from stick hits by a protective layer of foam or rubber. The peizos only need one impulse to trigger. The continuous rippling of resonance or vibrations from adjacent pads could confuse the brain and result in false triggering (not exactly a natural sound). With this in mind, deadening resonances and isolating from extraneous vibrations by utilizing foam and rubber insulation is essential.

An acoustic kit has a wide palette of sound options, such as side sticking on the snare, a bell sound on the cymbal, open and closed and everything in between on the hi-hat, and more. Strategically implementing two triggers on the snare or even up to three triggers on the hi-hat and cymbals can result in a more realistic playing experience by allowing for natural-sounding variations when coupled with a well-featured brain.

Sewing It All Together

Once you’ve gathered all your parts, the first step is to prepare them for assembly. You’ll want to be sure to make the correct measurements before you start drilling holes for any modifications, such as attaching the bass drum spurs and accommodating mounts for the triggers. This episode focuses on Jake’s operating table as he put together his Franken-kit. The approach will be a bit less involved if you choose the flat-pad triggering method.

Preparation

To begin, Jake installed the bass drum spurs on the “kick” tom. He planned on implementing a four-spur design to support the 12" tom above the ground. But another approach is to fashion a base out of wood that can be bolted to the bottom of the batter-side of the tom. This allows the pedal to be fastened to the drum in the correct position so that the batter hits the center of the head. Some experienced builders recommend using a section of a regular wooden bass drum hoop for use as a support and to anchor the pedal. Simply attach the section via long bolts to the underside edge of the drum.

Install the L-brackets on the “kick drum” and the snare to accommodate the crossbeam by first loosening the nut and washer on the lower of the two lug screws. Attach the L-bracket, replace the washer and nut, and tighten it down. Use the lugs laterally opposite each other on the snare drum, and adjacent lugs on the kick drum.

Now it’s time to measure and cut the metal bars you’ll be using as the crossbeams for the snare and kick drum. Using a hacksaw and a vice is the simplest way to do this. Mark the bar carefully so that it lines up with the L-bracket hole, and drill the holes. Then drill a hole in the middle of the bar and drill three smaller holes around it to accommodate the T-bolt and three screws to reinforce the assembly. The T-bolt will be the base for the trigger.

Use tin snips to cut out the metal discs upon which you’re going to mount the two piezos for the snare, as well as the one for the kick drum. This takes a bit of effort and the metal edges will be sharp, so it’s advisable to wear gloves. Jake used a thin but sturdy sheet of bronze. You want the discs to be slightly wider than the piezos themselves, which reinforces the pickup as well as increases its surface space. He also cut out a piece of bronze big enough to cover the playing area of his makeshift hi-hat pad.

Carve out moderately dense foam rubber discs to fit under the piezos and for insulating washers for metal-to-metal contact points. Then take the 3/8" auto tubing meant to insulate the rims and reduce vibrations, and cut it to length so that each piece can perfectly cover the circumference of each rim. Slit the tubing along its length. To make this easier, drill a 3/8" hole in a 2x4 piece of wood, and then drill through the end of the 2x4 to the hole so that you can insert a razorblade or Exacto knife. Clamp the wood to a table edge and run the tubing through the hole to slice evenly along the length (Fig. 1).

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Next you’re going to mount the bar to the L-brackets. The snare beam should be centered, but the bass drum beam will be across the top section of the drum. Now go ahead and install the T-bolt in the middle of the snare and kick drum crossbeams so that the T-bolt protrudes upwards toward the batter-side of the drum. Be sure to use rubber washers between the beam and the screws and nuts. Jake devised the insulated T-bolt approach for greater isolation.

The Trigger Assemblies

Solder the leads to the piezos if they aren’t already terminated: red wire to the outside area of the central element, and the black wire to the metallic edge. Glue the piezos metallic side down to the bronze discs that you prepared for the two snare triggers and the kick drum, and then use double-sided adhesive tape to fix the cone over the top of the piezo with the leads protruding out the side.

On both the snare and the kick drum T-bolts, glue a 1/4"-thick piece of foam rubber to the little round platform at the top, and then glue the disc/piezo/cone assembly on top of that. Make sure it’s secure. The cone should protrude about an eighth-inch above the bearing edge of the drum so that the mesh head will provide a bit of pressure. Place a ruler or similar flat object across the rim of the drum and eyeball the height of the cone. When the head is tightened down, the cone should displace the head upwards about a sixteenth of an inch. To attach the second “rimshot” trigger to the snare drum, simply glue a piezo directly to the crossbeam near the shell of the snare drum. This trigger will pick up the side sticking and rimshots.

Solder the piezo leads to the TS or TRS jacks (red to tip, black to sleeve) or directly to the cable (red to center conductor, black to shield). Be sure to figure out a good way to manage the cables by either securing them to the rack or stands with Velcro, or installing the jack directly into the shell of the drum if that’s feasible. Taming extraneous vibrations is key to controlling false triggering, so you can further isolate the bass drum shell by using an internal dampener or a thick piece of foam jammed into the cavity of the bass drum and pushed up against the head.

Setting up the Rototom triggers is pretty straightforward compared to the snare and bass drum experience, in that you’ll only be mounting the piezo directly to the center of the upper spoke. First, pad the center of the upper spoke with a 1/4" layer of foam rubber, and then put the head on. Measure the distance between the rubber pad and the head from underneath the drum, and add an extra eighth of an inch. Shear away the top of the cone so that its height matches that measurement. Then test it by putting the trigger with the shorn cone in place and reattaching the head to make sure it’s where it needs to be. Once you’re satisfied with the placement and pressure, glue everything down.

For the final touch on the drum pads, take lengths of 3/8" slit auto tubing and slide them over each of the rims of the toms, snare, and kick to cover the circumference. Glue the ends together so that each rim edge is neatly and completely padded with the rubber surface. Now you’re ready to attach the heads and rims and tune them up nice and snug so that the triggering is sufficient and the action feels good.

Hi-Hats And Cymbals

Last but not least on the assembly list are the cymbals and hi-hat. Jake used a set of Pintech practice cymbals and glued a layer of foam rubber over the striking area. After soldering each pair of piezo leads to a 1/4" jack, he then stuck a piezo to the underside of each cymbal with thin, double-sided foam tape, about halfway between the bell and the edge and just inside the little rectangular impression. You may opt to get more involved and go for two or three pickups to get edge, bow, and bell sounds. If you decide to use more triggers, make sure the brain you choose has enough inputs and features to handle it.

For a rough and simple hi-hat, Jake made a pad from a 12" disc of wood. He glued the piezo to the center of a 6" bronze disc, making sure the piezo made good contact with the disc, and soldered the leads to a 1/4" jack. He then glued a 3/8" layer of open-cell foam rubber over the wood disc, and glued the bronze plate to that so the piezo leads extended off to the back end of the disc. Over this he adhered a 1/4"-thick piece of Sorbothane (a visoelastic urethane similar to foam rubber). While this setup works sufficiently, it doesn’t provide for switching between open and closed hi-hat sounds, or any other variation.

Jake plans to go back and make a variable-control hi-hat, which can be done using either a simple switch/potentiometer assembly or a fairly straightforward fader device set up with a spring and a wire that attaches to a foot pedal on a traditional hi-hat stand. You could use plastic practice hi-hats or cheap brass hats to which you’ve glued a layer of rubber padding. This setup gives you a more realistic feel. The spring keeps the fader in the open position, and stepping on the pedal pulls the fader down, varying the voltage and therefore the hi-hat sound.

One thing to keep in mind is that a drum module’s variable hi-hat input wants to see a certain resistance value to work properly, and that value can vary between manufacturers. You may need to modify the fader/potentiometer you use to accommodate the requirements of the module. This is a simple procedure that involves soldering a resistor in parallel with the fader to achieve the desired load (per Ohm’s Law).

Once all the parts of the kit are assembled, attach everything to the frame. If you’re using a ready-made frame, you can employ the brackets to mount your pads. If you’ve made your own frame, use U-bolts and clamps and fashion mounts to attach your drums and cymbals. Traditional hardware can also be employed to get the kit standing steady and ready to play.

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The Brain

Now Igor, it’s onto the brain! You could pick up a brain for anywhere between $150 used on eBay, to $2,100 new out of the box. It really depends on how much flexibility you want and what your basic requirements are. If you were seeking a basic module to simply trigger sounds without a lot of extras, then a pre-owned older model, say the Alesis D4, would work just fine. But if you’re looking for a fully featured module with loops, effects, a metronome, a plethora of preset kits, an epic library of sounds, and flexible user-defined parameters, then something like the Roland TD-20 may be more up your alley.

Companies like Roland, Alesis, Yamaha, and ddrum offer a variety of drum modules to imbue your Franken-kit with life. A good comparison of brains can be found at drumjunction.com, hartdynamics.com, and drumbalaya.com. Things you should be looking at include the number of trigger inputs, variable hi-hat nuance control for a natural hi-hat sound, a good library of sounds, compatibility with various electronic kits, and whatever extras you may want, such as a metronome and built-in sequencer for programming loops to play along to.

If you want greater flexibility, consider getting a brain that features stereo inputs for dual triggering off of one jack. You could make multiple triggers on one sound source work with mono inputs, but you could be limited depending on the number of inputs. Most of the available drum modules today have a separate hi-hat input to handle the variations.

The Finished Product

There you have it, a basic foundation from which to start building your own electronic drum set. Of course, there are many different approaches and variations on what’s presented here, depending on how much time and money you want to spend and what you want to achieve. Online resources and forums for DIY electronic drum builders abound. You could create an entire kit, or even just build a few pads to enhance your acoustic setup. Hey, it’s your monster.