[Orb Vroomer]

A couple additions to the piezo article from dD. It was a fine article,but we've been nit picking our DIY talk in here for a long time,now.So why stop.I haven't looked into the other DIY forums mentioned,but we have some real good threads in OUR AM forum.Here goes.

Just one nit pick : paragraph 2 states "...converts pressure into energy".  NOT SO. That would be how an FSR works. A piezo converts "vibration" into energy.Which is the main reason we are trying to move to FSRs,rather than piezos - NO FALSE TRIGGERS FROM SYMPATHETIC VIBRATIONS. Later in the article,vibration was used,instead of pressure.

Why not go all the way- the piezos can be had @ Radio Snatch & the part # is 273-073.I didn't measure the millimeter diameter,but I've used many of these.Or better yet,if you have an electronics store,other than RS,wait RS,that's another chain.I get mine @ Gateway El. in ST. Lou. I've bought small ones for  10 cents - no plastic housing or wires.

Here are some sizes I've used,& more are available.

http://www.box.net/shared/mbv6qyxyy7

We DO have quite a lot of DIY info in here.I think we should re-invigorate our DIY FSR thread - daveb ? - you the man.I last posted in there - sounded negative - but all I was saying is we're NOT quite there yet.Or we can wait & see if & WHEN Miditronix will have an external FSR trigger. I want to move forward NOW. You guys who want 50 cymbal triggers - might be too expensive - unless we can build our own.Even Poles used to cost 160. So 25 (dual zone) X 160...$4,000.  TOO MUCH $ ..of course...that choice is gone.   Ray...Scotty.....any ideas ?

If not FSRs,then I have another variation of a pole pad....I saw many years ago @ NAMM.  About as successful as the $3,000 leather - piezo - jumpsuit.  But it was a good design - simple & hardly any parts.It has a playing surface similar to pole,not exact.Played with shaft - not tip.  So we will have 2 alternative pole designs with piezos ,plus if daveb or others get our FSR DIY - that would be awesome.

If 2010 is the decade of the digital drummer......then where in the hell are our FSR triggers ?  Been in Kats for 20 years.   What in the Force Sensing Resistor hell is going on here ?
And where is my George Jetson jet pack ?   

[vindrums]

    So ORB;
    Are we sure 'the shack' still carries these piezos? I know radio shack did, but what about now? I was quite surprised over the holidays when I sent my wife to grab a universal wall wart, like the kind we would use as a backup power supply. They used to have one that had switches to determine volts, and whether ac or dc, and they also had all the different adaptors with it. It used to be like ten bucks....A giant convenience!! I sent my wife with confidence, because I've got many over the years.....so anyway; They don't carry any such thing anymore.....yikes? Where do we go now? I saw noone answered the poster that asked where to get them......I was waiting for someone to answer. The new Shack?
Vince

[pljones]

Just one nit pick : paragraph 2 states "...converts pressure into energy".  NOT SO. That would be how an FSR works. A piezo converts "vibration" into energy.Which is the main reason we are trying to move to FSRs,rather than piezos - NO FALSE TRIGGERS FROM SYMPATHETIC VIBRATIONS. Later in the article,vibration was used,instead of pressure.

If we're gonna get picky .  What's a vibration other than a low frequency wave form?  Which means it's a variable pressure wave, just like any sound wave.  Hence you can use a piezo as a mic and a mic as a trigger.  I don't think (and I'm not entirely clear on how they work) that an FSR will pick up the waveform well -- my feeling is that doesn't respond to "negative" pressure - the other half-cycle of the wave.

[Orb Vroomer]

Yeah,plj, I prefaced with the 'nitpicking' concept. OK - hit a pad & keep pressure on it ( a piezo trigger). Now - as you are applying continuous pressure,does it trigger a 'roll' of notes ?
Now- beat on the housing of a piezo pad structure.Does it cause false triggers ?  Now - beat on the case of a DK or TK.Does it false trigger from 'vibration' ?  I KNOW WE know the answers to these ?s. I still say "if this is the decade of digital drumming", then give us some external FSR trigger pads !!  piezos are OLD SCHOOL.It's 2010.We put a man on the moon 40 years ago !!  

A kid has a demo on piezo pads on YT - 40,000 hits.....then he puts a meter on the piezo to check for polarity - he is suddenly confused - it works both ways !  So .....he concludes polarity test un-needed. I take everything I read & see with a grain of salt.Even 'expert' advise.  

Vince - Radio Snack still has those !  different packaging - same sku.  It's in that case with the slide drawers,now.Under piezo ' buzzers'.  I bought several in December for my Santa's band toy.  One was in there with a 3 wire connection & a little circuit - I don't know what it is for. Bummer about the adapter- wonder if Lowws has one ?  I'll check.

And if you want  another test for 'vibration'  ,find a car with an alarm,& put 'pressure' on the body.Alarm go off ? Now (not advised) ,hit the car body. Trip the alarm yet ?  It's a piezo.
Of course,the threshold setting has to be rather high,or else every time a heavy vehicle passes......vibration.....no pressure until the vehicles slam together - that should be enough 'pressure' to trigger the alarm.Or else the threshold is set a bit high.

How anal.  How does Webster define pressure VS vibration ? Does vibration CAUSE pressure ?  Maybe I should check before I write.I got a definition wrong before.Bottom line _ we all know & agree on the superior performance of an FSR VS piezo device.That's why the FSR pads on Kats have after touch - CONTINUOUS PRESSURE.  Impossible for a piezo to do this.But if it continually vibrates - that's a problem.
Most of this is for the novices in here - I know plj doesn't need my rantings..Rebuttels welcomed & encouraged.Another high jacked thread.Sorry.Maybe we should start a new thread.I will build some protos ,with piezos & when working I'll start a post with pictures.It's the 'ring of triggers' concept we've been talking about for our DKs & TKs.One curved bar.

Edit : after 15 minutes of contemplation ....it seems  - piezos trigger by pressure OR vibration,whereas, FSRs ONLY trigger from pressure.So I'll say Dd was correct & I was incorrect. 'Continuous'  is the adjective that's needs to be used for FSRs,not piezos.I just kept arguing with myself until I won.   

[digitalDrummer]

I'm glad you sorted that out!

[pljones]

Had a look at Wikipedia to see if it would help me understand...

Piezo = Piezoelectric sensor.  Which answers why you can't lean on a piezo and get a constant readout - they leak electrons.  But someone's commented: "Anyhow, it would be a misconception that piezoelectric sensors can only be used for very fast processes or at ambient conditions. In fact, there are numerous applications that show quasi-static measurements while there are other applications that go to temperatures far beyond 500°C."  (Vibration counts as a process; not sure what frequency counts as "very fast" here.)  "The voltage V at the source is directly proportional to the applied force, pressure, or strain."  So you get a variable voltage in response to vibration, which is how you use a piezo pickup on a guitar, for example.

FSR = Force-sensing resistor.  Does what it says: you determine the force by measuring the resistance (i.e. you supply your own voltage with an FSR rather then measuring a voltage as with a piezo).  A varying pressure gives you a varying resistance.

Now you can get false triggering from an FSR.  They're just less sensitive to it.  Looking at the physics, I'd say they're less sensitive overall, which means you have to build a much cleverer circuit to avoid false triggering with piezos.

Eventually I'll read the DIY article, honest!

[Orb Vroomer]

Thanks,plj & Allen. With some of the technical talk,I must avoid brain mush.     Plus,I had that steel cage death match argument with my own brain. 

Plj  - you didn't read the article yet ? That's funny.You should read it,for sure,but I don't think you'll find anything you don't already know.It is more of a starting point (ya know,1st issue),than some of our threads with more complete designs.This way,the dD mag can have articles dealing with other design concepts,in future editions.Oh yeah,that article was a response to a ? , so, lets ask "how do I build a complete 10" electronic drum ? "  Those instructions may not fit on just one page.But I'd like to see the answer.   

Drumkat & malletKat got a mention from Zdrum dude.It would be nice to see the premier interfaces get some face time in there.Can we 'drum' on a malletKat ?  Do I 'drum' on synthesizer sounds ? Will Digital Drummer cover tuned percussion ? & non percussion instruments,played via drumming ?  I'm just wondering  about a few things.I'll let dD sort it out.Can't wait to see the next issue.It was a great first issue.

[pljones]

Hey, I drum on my Evolution MK-249 keyboard when it's the only thing handy!   I'm sure you could do it better on a MalletKAT.  Gotta read the ZenDrum bits, too!  (I've been busy.  Finally fixed up some software bugs that have been outstanding since mid December... hopefully.)

[REF]

pl, hadn't noticed the Tony quote before. Great thoughts. The man is missed.

[pljones]

I think I nicked it from John Riley's "The Art of Bop Drumming".  One day I'll get past Comping 1...