Drum Conversion - Acoustic to Electric With DIY Heads and Triggers

Electric drum kits have recently become more mainstream with the development of their signal processing technology and their ability to closely reflect the feel and sound of a true acoustic kit. While they do seem to fall short in live performances compared to acoustic kits, they are ideal for beginners to learn and for seasoned drummers to quietly practice. They're also extremely useful for recording and developing tracks with MIDI. However, they can also be very expensive compared to acoustic kits.

I decided I wanted to start out with an electric drum kit to learn and practice quietly, but I also wanted the ability to convert to an acoustic kit if the occasion ever required. I was able to find a cheap but heavily used acoustic kit on Craigslist locally, and I decided this was the perfect opportunity to attempt an acoustic to electric drum conversion. I would be able to learn the ins and outs of electric kits, have the ability to fix or replace any parts that I break in teaching myself drums, and also convert back to acoustic easily without buying an entirely separate kit.

In this build I will be detailing how I created my own silent mesh drum heads, drum triggers for each piece of the kit, and built my own silent cymbals. I decided not to build my own signal processing module, and instead purchased a commercially available unit (Alesis Nitro) to do the heavy computing tasks.

Supplies

Parts

• Acoustic Drum Kit - Snare, High and Mid Toms, Bass, Floor Tom, Snare Stand, and two Cymbal Stand
• Alesis Nitro Module with Harness
• Alesis Nitro Hi-Hat Pedal
• Fiberglass Screen Mesh
• 1/4" OD Vinyl Tubing
• 35mm Piezo Sensors
• 1/4" TRS Jacks - With threaded shank
• Membrane Choke Switch

Supplies

• 1"x3" wood furring strips
• Small wood screws
• Double Sided Foam Tape
• Double Sided Clear Window Tape
• Electrical tape
• Heat Shrink
• Thin-gauge copper wire
• Metal Hanger Strap Roll
• Thin Plastic - I used a lid to a plastic storage tote
• Gym Mat Foam
• 1/8" Plywood

Tools

• Scissors
• Leather Hole Punch
• Drill
• Drill Bits and Driver
• Drum Key
• Tin Snips/Metal Shears
• Soldering Iron and Solder
• Wood Saw

Step 1: Full Video

If you're a visual learner, I documented the entire build process in this YouTube video, enjoy!

Step 2: Cleanup and Restoration

Before I got started on the conversion, I restored the acoustic kit by giving it a good clean and replacing some of the drum tension and tom-mounting hardware that had been broken from years of heavy use. Luckily all of the drum shells and stands were still in great shape.

The kit I found was only a five piece drum assortment and did not include cymbal stands or cymbals, so I purchased some cheap cymbal stands and a hi-hat stand from eBay.

I removed all of the heads from the drums and threw them away, as they were all so beaten up they were unsalvageable. When I convert the kit back to acoustic I will need to buy new drum heads and new cymbals.

Step 3: Make Mesh Drum Heads

This conversion will have two-ply mesh drum heads. There are many opinions as to what makes a good mesh drum head, and I settled on a two-ply system made from heavy duty fiberglass screen mesh. It can be found very cheaply and if I ever manage to break the heads I can easily replace them. The vinyl tube will be woven through the mesh and the drum rims will be applying tension to the tube pulling the heads evenly. The alternative of sewing the mesh onto a drum head ring will make for a much more difficult replacement and doesn't provide much more strength or rigidity in the long run.

1. Line up two layers of mesh
   1. Use binder clips to hold the layers together throughout this process
2. Trace the drum ring's circle onto the mesh
3. Cut out the mesh in a circle approximately 2 inches in diameter LARGER than the circle you traced
   1. This excess will allow room for tightening the mesh heads to your desired tension
4. Draw dots spaced about 1 inch along the entire circumference of the circle you traced
   1. Make sure an even number of dots are drawn on
5. Punch holes on each of the dots through both mesh layers
6. Wrap a length of vinyl tubing around the drum shell and mark where the ends meet
7. Cut the tubing on the mark so that the length is the same circumference as the outside of the drum shell
8. Weave the tubing through each hole punched in the mesh
9. Secure the ends with some strong tape
10. Repeat this process for each drum shell in your kit

Step 4: Drum Triggers

Drum triggers convert the vibration and velocity of the drumsticks striking the drum head into an electrical signal to be processed by the module. Once again there are many methods for adding drum triggers to a kit, but I decided to make my own triggers and install them on a brace inside each shell, as opposed to a premade trigger added to the outside of the shell. Repeat the process below for each drum in the kit, including the bass drum

Trigger Brace

1. Measure and cut a wood brace (1"x3") to fit inside the drum shell
2. Remove a tension lug screw on either side of the shell
3. Install an angle bracket onto each lug (horizontal arm up) with the lug screw you removed
4. Screw the wood brace onto the bracket with small wood screws
   1. Drill a pilot hole with a small drill bit to prevent cracking in the wood
5. Mark the center of the brace and draw a dividing line
6. On the center of the wood brace, place a layer of doublestick foam tape on either side of the center dividing line
7. Stick a layer of metal strips to cover the foam tape
   1. Cut metal strip using tin snips/metal shears
8. Place a roughly dime-sized layer of doublestick tape (non-foam) over the center of the metal layer
9. Set the drum shell aside to await placement of the trigger

Trigger Wiring

1. First you want to identify which pins on the 1/4" TRS jacks are which. There is a Tip, Ring, and Sleeve pin that contacts the tip, ring, and sleeve on the plug of the wiring harness. It helps to insert the plug into the jack to determine which pin is contacting which section of the plug.
2. Each piezo sensor has a signal wire (red) and a ground wire (black). The signal wire will be soldered to either the tip or the ring pin, but the ground wire(s) will always be soldered to the sleeve
3. Typically the red signal wire is soldered to the tip pin, but if you will be having a second piezo in the trigger it will need to be soldered to the ring pin. A second piezo will offer you a secondary sound, such as a rim shot on the snare drum or a bell on the ride cymbal. Look closely at the harness plugs to see which plug can accommodate a secondary ring piezo
4. Based on the length of the wires, they may need to be extended to reach the position of the jacks
5. Solder the wires to their respective pins - Signal 1 to Tip, Signal 2 to Ring, and Ground(s) to Sleeve
6. Secure each solder with electrical tape or heat shrink

Mounting Piezos

1. Secure the primary piezo to the double stick tape on the trigger mount.
   1. Press firmly but not so hard that you crack the piezo.
2. If you have a secondary piezo to mount as a rim shot, secure it to the wall of the drum shell with double stick tape.
   1. Because you are not sending the vibrations from the rim directly to the piezo and not through a mesh drum head it is far less complicated for a rim trigger
3. The foam cone is going to translate the vibration from a hit anywhere on the mesh head to the piezo in a way that makes the drum sound more realistic. The more perfectly shaped you can make the cone, the better it will sound
   1. Use scissors or a knife to cut the cone out of foam, don't worry about the height at this point. The base of the cone should be the same diameter as the piezo sensor
   2. Place the cone on the center piezo. The correct height should be such that the tip comes above the line of the drum shell's rim by 1.5mm. I placed a metal carpenter square on the shell and marked where it met the foam. Cut the cone at this height
   3. Use some more clear doublestick tape on the bottom of the foam cone, and stick the base to the top of the piezo
4. Lastly, drill a hole through the drum shell to mount the 1/4" jack.
   1. Choose a location on the shell that will allow the module wires to reach their respective jacks when the kit is set up
   2. Start small and use progressively larger drill bits in order to prevent cracking the wood and shell wrap
   3. If the shank of the jack's threads are too small to go all the way through the mounting hole, you may need to carve out the inside of the shell with a rotary tool to thin that portion of the wall enough so that you can get the nut onto the threads on the outside of the shell
5. Place the mesh head over the shell, place the drum rim over the head, and tighten it down to your desired tension.
   1. Make sure the inside of the rim holds the vinyl tubing all the way around to provide even tension across the head.
   2. Do not overtighten as it is possible to rip the mesh from overtightening.

Step 5: Build Cymbals

The cymbals are a much simpler affair than the drum triggers. You will be using more piezos and jacks and wiring them similarly to the drum triggers.

1. Cut a circle from the thin plastic to your desired dimensions. I used the high tom's shell diameter for the crash and ride cymbals, and the small container for the hi-hat diameter
2. Drill holes in the center of each cymbal for the cymbal hardware to go through. I reused the cymbal hardware from each cymbal stand
3. Cut several circles in the 1/8" plywood. You will need two circles for each cymbal. I used the double stick tape's diameter for the crash and ride cymbals' disks, and the electrical tape diameter for the hi-hat.
   1. The wood circles provide support and structure to each cymbal, as the plastic is thin and flimsy.
   2. Drill similar center holes through each wood disk
4. Cut a piece of gym mat foam to cover the top of the cymbal, I chose to only cover half but you can choose to cover the whole area. Leave a section in the center for the wood disk to fit
   1. The foam is meant to protect the piezo and silence the strike on the cymbal
5. Secure the piezo to the plastic with clear double stick tape
6. Solder lengthening wires as needed, and solder the signal and ground of the piezo to the jack tip and sleeve.
   1. I chose to mount the piezo on the top of the cymbal and drilled a small hole to route the wires and mount the jack on the bottom of the cymbal
7. Mount the jack to the back of the cymbal with some double stick foam tape
8. I chose to mount a secondary piezo on the ride cymbal to give a "bell" sound in addition to the ride sound. I used some tape to stick it to the wooden disk and placed a foam circle on top of the disk to protect it. I soldered it to the ring pin on the jack
9. I also chose to install a "choke" switch to the ride cymbal. This switch is used to pinch the crash cymbal to cut off the reverberation, similar to choking a real crash cymbal. The choke switch can be soldered to the ring pin on the crash's jack. I stuck a small piece of gym foam to the choke switch on the underside of the cymbal to protect it as well
10. Secure any dangling wires with electrical tape.
11. Stick the gym foam pads over the piezos with some double stick tape or glue

Step 6: Put It All Together

Drums

1. Set up the bass drums, toms, and snare with snare stand as you normally would
2. Plug in each labeled module harness plug into its respective jack.

Cymbals

1. Mount the cymbals to each cymbal stand. Make sure that each cymbal is "sandwiched" with a wooden disk mounted between the cymbal hardware.
2. Plug in each module plug onto its respective cymbal jack
3. Set up the hi-hat pedal beneath the hi-hat stand, and plug in the corresponding 1/8" plug from the module's harness

Module

1. Mount the module to the drum kit. I found that a tom-mounting arm fits snugly onto the module's mounting pipe. The tom arm can then be mounted onto a cymbal stand with a bracket.
   1. Any mounting solution will work so long as the module is accessible and doesn't move around when playing
2. Plug and secure the harness into the back of the module with the included screws
3. Secure all dangling wires around the kit with Velcro straps or cable ties

Practice!

1. Plug headphones or a small practice amp into the module to begin practicing. Tune each of the triggers with the module to get your desired sounds and sensitivities
2. Play with MIDI and VSTs
   1. I use a free software called Waveform and the ASIO4ALL driver to connect the drums to a computer over the USB plug on the module. This allows me to add even more functionality to the already capable module
3. Enjoy your new drums. I've found that it is really nice to practice quietly with headphones, and learn a lot of the fundamentals. I also really like that I'm able to convert all of the shells back to acoustic simply by removing the trigger braces and plugs, and adding real cymbals

Thank you for reading this Instructable, I hope you enjoyed it and are able to use it to make your own kit. Feel free to ask questions!