Yamaha DTXpress/DTXplorer/DTXtreme

FSRs & piezos...Ok I know what a piezo is, but what's an FSR? 

Today I bought a piezo at Radio Shack to experiment and if I can 
make a trigger. Just took the piezo as it is in it's housing, wired 
it to a 1/4" jack and "shazam" it works!
Though I find that the piezo alone is louder than any of my Yamaha 
pads. I figure partly due to me hitting on the piezo directly itself 
vs an impact of a hit spread out within a pad, and also the Yamaha 
pads have a volume of sorts...?

For $1.49 plus tax it sure makes a cheap trigger!:)

--- In DTXpress@yahoogroups.com, "zapaxe" <a_zapelectric@h...> wrote:
> 
> FSRs & piezos...Ok I know what a piezo is, but what's an FSR? 
> 

Force sensitive resistor.  In English - a rubber switch.

Be careful hitting piezos directly - I know they are cheap but they
can easily be broken if they are thin.

Keith.

--- In DTXpress@yahoogroups.com, "Keith" <keith@k...> wrote:
> 
> --- In DTXpress@yahoogroups.com, "zapaxe" <a_zapelectric@h...> 
wrote:
> > 
> > FSRs & piezos...Ok I know what a piezo is, but what's an FSR? 
> > 
> 
> Force sensitive resistor.  In English - a rubber switch.
> 
> Be careful hitting piezos directly - I know they are cheap but they
> can easily be broken if they are thin.
> 
> Keith.

---------------------

Thanks Keith,


Hmmm...I remember seeing a diagram, pictures of a pad torn apart and 
explanantion of different trigger types within a dual trigger Yamaha 
pad a couple of years ago. This was on a DTXpress site of some sort 
that I don't have saved anymore. I remember the site's main page 
showing a picture of the 'DTXpress I' module at the time.

Is there a link to what this FSR (rubber switch) looks like for an 
example? Your explanation seems very clear, but I still would know 
one if it bit me:o
I'd like to experiment and make some trigger pads of some kind. I 
know I can use the piezo for a single trigger device, but if I want 
to make a dual trigger device I'll need to get my hands on one of 
these FSR's no doubt.
I'm guessing that these piezo's and FSR switches are used in a dual 
trigger pad so that the pad can't trigger two sounds due to the 
vibration, as well as the module being designed for this.

Last night I was experimenting with a stereo 1/4" phone plug and 
that piezo (still in it's plastic housing at this time & I was 
tapping it lightly) I connected the wires to the (black wire) 
grounds on both the piezo & 1/4" stereo phone plug. I then touched 
the positive (red) wire from the piezo to the center to middle 
connections on the stereo plug. 
It only made a sound on one - I 'think' center connection??? Anyway, 
I'm guessing that the piezo is for the pad sound and this FSR switch 
is for the rim sound of say a dual trigger pad and that's why I only 
get one sound.

Naturally is I plug into the 9/10 jack of the module I get TWO 
sounds by touching my possitive lead to the center & middle 
connections on the 1/4" phone plug. 
I do understand 'somewhat' that the 9/10 jacks are capable of 
producing sounds from two different sources or pads if a 'Y' cable 
is used, while the other trigger inputs (snare, toms etc..) cannot. 
But these 'others' can trigger two sounds from a dual trigger pad.

--- In DTXpress@yahoogroups.com, "zapaxe" <a_zapelectric@h...> wrote:
> 

You are right - it is the tip of the jack plug which connects to the
piezo.  The ring is connected to the FSR.  When you hit the rim of the
pad the FSR shorts the ring to ground.  In the case of a three zone
pad, the extra zone is created by using a 10k resistor in series with
the FSR.  By the way, if you try shorting out the ring and then
hitting as pad it won't work.  The DTXpress box expects the switch to
be closed just before the piezo signal arrives.  Try holding the rim
of you snare and hitting the pad and see what happens.

If you look in the photo section, someone (OGD I think) has kindly
dismantled and photographed just about all the Yamaha kit.

I think there were discussions about FSRs on the group a while back,
including where to buy them, so if you search the message archive you
should find it.

Keith.

Hi Keith,

Great, thanks for the extra info! I had a look at those photo's
and did a search. 
The photo's showed a ribbon connected to the edge of a pad, I'm 
guessing that's the FSR. I can't tell in the picture exactly how the 
rim shorts when it get's hit though. I do see how the ribbon 
attaches to the edge and seems to slit off in bith directions of the 
edge of the cymbal pad shown.
I've not found anything in the "search" yet, except our dialog by 
typing in FSR :/ I'll try typing in something else.
This helps a lot, thanks again!

Steve

--- In DTXpress@yahoogroups.com, "Keith" <keith@k...> wrote:
> 
> --- In DTXpress@yahoogroups.com, "zapaxe" <a_zapelectric@h...> 
wrote:
> > 
> 
> You are right - it is the tip of the jack plug which connects to 
the
> piezo.  The ring is connected to the FSR.  When you hit the rim of 
the
> pad the FSR shorts the ring to ground.  In the case of a three zone
> pad, the extra zone is created by using a 10k resistor in series 
with
> the FSR.  By the way, if you try shorting out the ring and then
> hitting as pad it won't work.  The DTXpress box expects the switch 
to
> be closed just before the piezo signal arrives.  Try holding the 
rim
> of you snare and hitting the pad and see what happens.
> 
> If you look in the photo section, someone (OGD I think) has kindly
> dismantled and photographed just about all the Yamaha kit.
> 
> I think there were discussions about FSRs on the group a while 
back,
> including where to buy them, so if you search the message archive 
you

> should find it.
> 
> Keith.

--- In DTXpress@yahoogroups.com, "zapaxe" <a_zapelectric@h...> wrote:
> 
> Hi Keith,
> 
> I've not found anything in the "search" yet, except our dialog by 
> typing in FSR :/ I'll try typing in something else.
> This helps a lot, thanks again!
> 

Steve,

I found plenty of references to FSR, but not the information I thought 
I saw. I also tried "ribbon". I don't know if you know that you need 
to keep pressing "next" after your first search because it only 
searches the archive a bit at a time.  Thread 8723 has a discussion 
you might find useful.  I also tried the electronic drum forum in case 
I had seen it there, but no luck.  If you search the web with google 
for FSR or "force sensitive resistor" you will find enough links to 
keep you out of trouble for a while.

Keith.

> Steve,
> 
> I found plenty of references to FSR, but not the information I 
thought 
> I saw. I also tried "ribbon". I don't know if you know that you 
need 
> to keep pressing "next" after your first search because it only 
> searches the archive a bit at a time.  Thread 8723 has a 
discussion 
> you might find useful.  I also tried the electronic drum forum in 
case 
> I had seen it there, but no luck.  If you search the web with 
google 
> for FSR or "force sensitive resistor" you will find enough links 
to 
> keep you out of trouble for a while.
> 
> Keith.

Thanks for your effort Keith,

I'll try the Google search as well. I did have a look through 
some "Do It Yourself" e-drum building sites and there was something 
for a choke circuit for cymbals, and piezo's but didn't see specific 
FSR's and how they work so far. I 'guess' these 'DIY' sites may be 
the best option to learn how to actually make one and where to get 
them.

Steve