E-Cymbals --- Splash & Crash

[John F]

Hi,
New member, long time lurker. I'm working on an acoustic to electronic conversion and this forum has been a great source of information. Thank you all!

I've got my splash, crash, and ride cymbals built and working. I'm attaching pictures of the splash and crash cymbals. The splash is a 10" Pintech practice cymbal using a 35 mm piezo from DigiKey. On the top of the cymbal I'm using a cut up Vic Firth drum mute glued in place. The crash is a 14" Pintech practice cymbal, also using a 35 mm piezo from DigiKey and cut up Vic Firth mute. I'm using an electronic (no moving parts) touch switch for muting. The (normally open circuit) switch is made from two metal strips glued to the edge of the cymbal with about 1/8" spacing between them. Grabbing the edge of the cymbal completes the circuit and mutes the cymbal. The electronics to do this mount on a small piece of perfboard in a plastic Radio Shack project box. The circuit draws a very small amount of current (< 1 milliamp) only when choking the cymbal. The battery should last for nearly its shelf life under these conditions, so no on/off switch is necessary.

[SuperPuss]

Welcome aboard John
That's a neat little choke circuit. I like your use of the PNP transistor to drive the output switch. Simplifies the biasing between stages and, as you say, minimises standby current drain

I was thinking of doing something similar with either a passive darlington pair or maybe a jfet. I measured the open circuit voltage across the choke on my TD12 trigger inputs and it should be adequate to supply such a circuit but the current capacity is minimal (around 20 microamps from memory) so it might take a little experimentation with various transistor types to find something reliable under these conditions.

[Hellfire]

Hi,
New member, long time lurker. I'm working on an acoustic to electronic conversion and this forum has been a great source of information. Thank you all!

I've got my splash, crash, and ride cymbals built and working. I'm attaching pictures of the splash and crash cymbals. The splash is a 10" Pintech practice cymbal using a 35 mm piezo from DigiKey. On the top of the cymbal I'm using a cut up Vic Firth drum mute glued in place. The crash is a 14" Pintech practice cymbal, also using a 35 mm piezo from DigiKey and cut up Vic Firth mute. I'm using an electronic (no moving parts) touch switch for muting. The (normally open circuit) switch is made from two metal strips glued to the edge of the cymbal with about 1/8" spacing between them. Grabbing the edge of the cymbal completes the circuit and mutes the cymbal. The electronics to do this mount on a small piece of perfboard in a plastic Radio Shack project box. The circuit draws a very small amount of current (< 1 milliamp) only when choking the cymbal. The battery should last for nearly its shelf life under these conditions, so no on/off switch is necessary.

Your cymbals look great! I once thought about doing the choke as you have it, but I came up with what I thought might be a simpler solution. You can see my solution on this post: http://vdrums.com/forum/showpost.php...15&postcount=9

You can also just check out my original post from my website on this subject:
http://www.hellfiredrums.com/archives/67

I like your ride cymbal too!

[Gastric]

John, quickie about your touch-switch circuit. Instead of big strips of bulky and unsightly metal (not that anyone REALLY looks at the bottom of cymbals) could you simply use two bare copper wires run closely in parallel? Also, what specific power source did you use? It apperas you indicate 9V in the circuit diagram but none of the photos appear to include an external power source. Certainly 1.5V button battery would be a smaller, though more expensive, power solution?

[John F]

John, quickie about your touch-switch circuit. Instead of big strips of bulky and unsightly metal (not that anyone REALLY looks at the bottom of cymbals) could you simply use two bare copper wires run closely in parallel? Also, what specific power source did you use? It apperas you indicate 9V in the circuit diagram but none of the photos appear to include an external power source. Certainly 1.5V button battery would be a smaller, though more expensive, power solution?

Yes, bare copper wires would work fine. For power I'm using a 9V battery. The battery can either go inside the box, or plug in through the RCA connector shown on the side of the box. I'm planning to have several of these powered boxes when I'm done and rather than use several batteries I am planning to mount them all together like how guitar effects pedals are all mounted on a pedal board. That way I can use a single power source, either the battery or the DC supply to my module. I ran some circuit simulations using 3 volt and 1.5 volt sources. 3 volts will probably work OK but the range of "touch" resistance (the resistive path through your fingers when touching the switch) is not as great compared to 9 volts. 1.5 volts may not work very well. The "touch" resistance range is reduced even further and the current that the NPN transistor needs to pull down becomes critical. You could try a CR2032 battery. It's 3 volts and about the size of a nickel. You can find them at your local Ace hardware or Food Lion at Falls Village. Sam's Club has them by the 12 pack and the cost per battery is about 1/2 that of buying them 1 at a time.

[suedehead]

There has to be a separate power source to make these chokes operate? How do the Roland or hart systems work? Where are you mounting a 9 volt battery at?

[Gastric]

I think for the most of us we'd want a battery self-contained in the project box. Jamming the board, jacks, and a big 9V and two AAs, plus a piezo, isn't going to work. At least with the tiny sized boxes.

That's where I thought the button batteries would work. At least in the picture of your open project box it looks like there's plenty of room for a battery harness/connector/whatever-the-electronics-term-is and a battery without interfering with any of the other parts in the box.

Your external power source saves the battery completely, which is smart. But requires another wire running to the cymbal. Not that it's the end of the world. I'm still just searching for the "most perfect" solution in my particular eyes. Couple copper wires run in parallel to a tiny, simple, box with a tiny button battery is close.

[SuperPuss]

Yes, bare copper wires would work fine. For power I'm using a 9V battery. The battery can either go inside the box, or plug in through the RCA connector shown on the side of the box. I'm planning to have several of these powered boxes when I'm done and rather than use several batteries I am planning to mount them all together like how guitar effects pedals are all mounted on a pedal board. That way I can use a single power source, either the battery or the DC supply to my module. I ran some circuit simulations using 3 volt and 1.5 volt sources. 3 volts will probably work OK but the range of "touch" resistance (the resistive path through your fingers when touching the switch) is not as great compared to 9 volts. 1.5 volts may not work very well. The "touch" resistance range is reduced even further and the current that the NPN transistor needs to pull down becomes critical. You could try a CR2032 battery. It's 3 volts and about the size of a nickel. You can find them at your local Ace hardware or Food Lion at Falls Village. Sam's Club has them by the 12 pack and the cost per battery is about 1/2 that of buying them 1 at a time.

By the time you factor in the 0.6 - 0.7 volt drop across the base - emitter junctions on each transistor, I can see the 1.5 volt source being very borderline for biasing.
Stacking three CR2032's would give the recommended 9v at a much reduced size over a 9v battery.

[John F]

Stacking three CR2032's would give the recommended 9v at a much reduced size over a 9v battery.

Yes it would. At about twice the cost of a plain ol' 9V battery Plus you'd have to factor in some kind of holder to hold the 3 batteries together.

[Gastric]

Just in case someone wants to source the components for John's circuit at Radio Shack. I've included the parts for using a 3V button battery, assuming it will fit on the board. Note I'm no electronics genius so it's entirely possible I've sourced wrong parts for the circuit based on John's schematics.

I didn't source the perf board or leads. But Radio Shack sells those as well. I see various sized board and at least one collection of pretty colored pre-stripped leads. Though you can obviously make your own leads.



2N3904 NPN Small Signal Transistor
$0.79
Model: 2N3904
Catalog #: 276-2016
http://www.radioshack.com/product/in...Id=2062609&cp=

PNP Amplifying Transistors (15 pack)
$2.59
Model: 2N3906
Catalog #: 276-1604
http://www.radioshack.com/product/in...Id=2062585&cp=http://www.radioshack.com/product/in...Id=2102516&cp=

1M ohm 1/2W 5% Carbon Film Resistor (5 pack)
$0.99
Model: 271-1134
http://www.radioshack.com/product/in...Id=2062337&cp=

47K ohm 1/2W 5% Carbon Film Resistor (5 pack)
$0.99
Model: 271-1130
http://www.radioshack.com/product/in...Id=2062333&cp=

10K ohm 1/2W 5% Carbon Film Resistor (5 pack)
$0.99
Model: 271-1126
http://www.radioshack.com/product/in...Id=2062330&cp=

22K ohm 1/2W 5% Carbon Film Resistor (5 pack)
$0.99
Model: 271-1128
http://www.radioshack.com/product/in...Id=2062331&cp=

CR2032 3V/230mAh High Energy Lithium Battery
$4.99
Model: CR2032
Catalog #: 23-162
http://www.radioshack.com/product/in...Id=2062105&cp=

CR2032 Battery Holder
$0.99
Model: 270-009
http://www.radioshack.com/product/in...Id=3060977&cp=

[Mraverty]

Just out of curiosity, what did you use for the rubber muting, and how well does it kill stick sound?

[John F]

Just out of curiosity, what did you use for the rubber muting, and how well does it kill stick sound?

I used a Vic Firth drum mute, cut to cover about a 120 degree sector on the cymbal. Gluing it to the cymbal is a bit tricky. I know several different glues that don't work . I finally ended up using a spray contact adhesive on both the back of the pad and the cymbal. It kills the stick sound quite well compared to no pad.

[John F]

Just in case someone wants to source the components for John's circuit at Radio Shack. I've included the parts for using a 3V button battery, assuming it will fit on the board. Note I'm no electronics genius so it's entirely possible I've sourced wrong parts for the circuit based on John's schematics.

I didn't source the perf board or leads. But Radio Shack sells those as well. I see various sized board and at least one collection of pretty colored pre-stripped leads. Though you can obviously make your own leads.



2N3904 NPN Small Signal Transistor
$0.79
Model: 2N3904
Catalog #: 276-2016
http://www.radioshack.com/product/in...Id=2062609&cp=

PNP Amplifying Transistors (15 pack)
$2.59
Model: 2N3906
Catalog #: 276-1604
http://www.radioshack.com/product/in...Id=2062585&cp=http://www.radioshack.com/product/in...Id=2102516&cp=

1M ohm 1/2W 5% Carbon Film Resistor (5 pack)
$0.99
Model: 271-1134
http://www.radioshack.com/product/in...Id=2062337&cp=

47K ohm 1/2W 5% Carbon Film Resistor (5 pack)
$0.99
Model: 271-1130
http://www.radioshack.com/product/in...Id=2062333&cp=

10K ohm 1/2W 5% Carbon Film Resistor (5 pack)
$0.99
Model: 271-1126
http://www.radioshack.com/product/in...Id=2062330&cp=

22K ohm 1/2W 5% Carbon Film Resistor (5 pack)
$0.99
Model: 271-1128
http://www.radioshack.com/product/in...Id=2062331&cp=

CR2032 3V/230mAh High Energy Lithium Battery
$4.99
Model: CR2032
Catalog #: 23-162
http://www.radioshack.com/product/in...Id=2062105&cp=

CR2032 Battery Holder
$0.99
Model: 270-009
http://www.radioshack.com/product/in...Id=3060977&cp=

Those are the parts that I used for the most part. Chances are you sourced them from the same RS I bought them from . unless you did it on-line. The perfboard was also bought at RS and cut to fit the box.

[John F]

There has to be a separate power source to make these chokes operate? How do the Roland or hart systems work? Where are you mounting a 9 volt battery at?

Yes, because it's electronic and has no moving parts. Don't know how Roland or Hart systems work. My guess would be some kind of mechanical switch. You can mount a 9V battery either insde the box or external to it. No on/off switch is needed as it only draws current when the cymbal is choked so the battery should last basically its shelf life in this application. However, I'm using an external 9V supply to run mine, as I have several. Also note that I am not mounting this box on the cymbal so there is no extra wire to the cymbal. These will be floor mounted, like guitar effects boxes are mounted on a pedal board.

[vdrummer20]

Nice job. I am looking to add another splash, but with no muting (I already have a CY5 for this). This is great!