Yamaha DTXpress/DTXplorer/DTXtreme

Hi all,

Many of you will have seen discussions about the "Magic Box" which
will allow two pads to use one input on the DTXpress, and also combine
two piezos from a single pad into a single piezo and rim switch signal
for use on the DTXpress (some non Yamaha dual zone pads use two piezos
instead of a single piezo and a rim switch).

I have designed a circuit which does a reasonably good job of doing
this and a few people have tried it out.  It is not 100% perfect and I
am not sure it ever will be - it has to work within what the DTXpress
expects from a pad with rim switch - but it is pretty good.  However,
I am not sure it will be viable as a commercial product and am not
prepared to spend a lot of my own money to find out.

As the original "Magic Box" was quite complex, I have come up with a
simplified idea which should be within the abilities of anyone who
wants to have a go.  The components will only cost a few cents and the
circuit is "passive" in that it does not use any external power (but
has an "active" component).  I have given it a quick try and it works
and should be good for a typical use where you want to add a few pads
for cow bells, extra cymbals etc.  Bear in mind that when combining
two pads into one input you can only get one sound at a time (although
you can get both if one hit is slightly after the other) so you need
to choose your combinations with some thought (ie don't combine the
kick drum, snare or high-hat with anything).

With a few extra components you could also combine three pads into
one.  I have posted a circuit to the files section.  It is supplied
without any warranty, but as it has now power, it is difficult to see
how it can damage anything.  I have not optimised the component values
- I haven't time at the moment - so you may want to play around with them.

I will try to answer any questions posted to the group as quickly as
possible.  If anyone wants the more complex circuit, please ask.  It
has opamps, comparators, inductors, power supply etc and would need a
stripboard or something similar to build it on.  The parts to build
one would probably cost around $100 (I am not sure of USA component
prices) and it would combine 8 channels into 4.

Keith.

Keith,
Kudos to you (and those that have helped you test) for all your hard 
work on the Magic Box circuits! The "passive" circuit is very
exciting 
and I'm looking forward to swapping out my trigger box with your more 
elegant implementation. Time to go build more cymbal triggers! Thanks 
again.
- Rudy


-------------
Yamaha DIY Drumset
www.htmediaservices.com

Hi Keith,

I remember this one...Cool I'll have a look at it..though I have 3 
drum trigger modules and more pads than I can shake a stick...or two 
at by now...None the less, this is a great concept for those in 
need, and I'm curious as well as I find it very interesting :)

Steve



--- In DTXpress@yahoogroups.com, "Keith" <keith@k...> wrote:
> Hi all,
> 
> Many of you will have seen discussions about the "Magic Box" which
> will allow two pads to use one input on the DTXpress, and also 
combine
> two piezos from a single pad into a single piezo and rim switch 
signal
> for use on the DTXpress (some non Yamaha dual zone pads use two 
piezos
> instead of a single piezo and a rim switch).
> 
> I have designed a circuit which does a reasonably good job of doing
> this and a few people have tried it out.  It is not 100% perfect 
and I
> am not sure it ever will be - it has to work within what the 
DTXpress
> expects from a pad with rim switch - but it is pretty good.  
However,
> I am not sure it will be viable as a commercial product and am not
> prepared to spend a lot of my own money to find out.
> 
> As the original "Magic Box" was quite complex, I have come up with 
a
> simplified idea which should be within the abilities of anyone who
> wants to have a go.  The components will only cost a few cents and 
the
> circuit is "passive" in that it does not use any external power 
(but
> has an "active" component).  I have given it a quick try and it 
works
> and should be good for a typical use where you want to add a few 
pads
> for cow bells, extra cymbals etc.  Bear in mind that when combining
> two pads into one input you can only get one sound at a time 
(although
> you can get both if one hit is slightly after the other) so you 
need
> to choose your combinations with some thought (ie don't combine the
> kick drum, snare or high-hat with anything).
> 
> With a few extra components you could also combine three pads into
> one.  I have posted a circuit to the files section.  It is supplied
> without any warranty, but as it has now power, it is difficult to 
see
> how it can damage anything.  I have not optimised the component 
values
> - I haven't time at the moment - so you may want to play around 
with them.
> 
> I will try to answer any questions posted to the group as quickly 
as
> possible.  If anyone wants the more complex circuit, please ask.  
It
> has opamps, comparators, inductors, power supply etc and would 
need a

> stripboard or something similar to build it on.  The parts to build
> one would probably cost around $100 (I am not sure of USA component
> prices) and it would combine 8 channels into 4.
> 
> Keith.

--- In DTXpress@yahoogroups.com, "PFozz \(EDrum For Free\)"
<edrum.for@f...> wrote:
> Keith, should I contact you somewhere, or should we talk about it here ?

No hard and fast rules.  If you think that what we discuss will
benefit other people then do it here.  If what you are doing is so
wierd that it will only bore the pants off everyone else, send me an
email!

Keith.