Yamaha DTXpress/DTXplorer/DTXtreme

I have been experimenting with the DTXpander/"Magic box" with a
Pintech Concertcast snare on my Yamaha DTXpress.  One problem I
noticed was that it wouldn't respond to a small hit after a very
strong hit when using the box.  I tracked the problem down to the
series diode, D3, in the DTXpander, which has an optional jumper on
it.  With the diode shorted out, it works fine.  What seems to be
happening is the positive pulse caused by the diode charges up an AC
coupling capacitor in the DTXpress and that takes time to discharge
(presumably through R3).  Reducing R3 may also help, but I haven't
tried it.  Shorting the diode works well.

I thought I would post this information in case anyone else has had
the same problem.

Keith.

--- In DTXpress@yahoogroups.com, "Keith" <keith@...> wrote:
>
> I have been experimenting with the DTXpander/"Magic box" with a
> Pintech Concertcast snare on my Yamaha DTXpress.  One problem I
> noticed was that it wouldn't respond to a small hit after a very
> strong hit when using the box.  I tracked the problem down to the
> series diode, D3, in the DTXpander, which has an optional jumper on
> it.  With the diode shorted out, it works fine.  

Keith,

Have you tried the snare directly into the module?  We've always found 
that the module itself limits the snare's dynamic range, seriously 
shortchanging the softer end, as if the gain were stuck on high. 
(Other modules can compensate for comnpromises in sensitivity but not 
the Yamaha.)  The traditional remedy has been to insert a 250k pot 
between the Pintech snare and module to tame the beast (like a 
Guyatone cable, which has a rotary control built in). Do you have any 
ideas besides use of the DTXpander--not that I want to discourage 
anyone from using it, 

Ed

> Have you tried the snare directly into the module?  We've always found 
> that the module itself limits the snare's dynamic range, seriously 
> shortchanging the softer end, as if the gain were stuck on high. 
> (Other modules can compensate for comnpromises in sensitivity but not 
> the Yamaha.)  The traditional remedy has been to insert a 250k pot 
> between the Pintech snare and module to tame the beast (like a 
> Guyatone cable, which has a rotary control built in). Do you have any 
> ideas besides use of the DTXpander--not that I want to discourage 
> anyone from using it, 

Ed,

Yes, I am currently running it directly into the module (mainly
because, while I bought the 2 zone ConcertCast, hitting the metal ring
gives a loud smack so the dual piezo isn't really required!).  I
measured the signal from the ConcertCast on my oscilloscope and
compared it with the DTXtreme 10" tom pad I had been using and found
the maximum signal levels to be similar.  

I agree that you can play the ConcertCast softer and I have currently
set Gain=80 MVel=15 with the pad set to TP1/SnrA.  It seems to give
the full dynamic range, although I am not the most subtle of players.
 One noticable difference is the Yamaha pads give a reasonably
consistent sound level across the pad whereas the ConcertCast gets
progressivley quieter towards the edge, presumably more like a real drum.

Keith.

> Have you tried the snare directly into the module?  We've always found 
> that the module itself limits the snare's dynamic range, seriously 
> shortchanging the softer end, as if the gain were stuck on high. 
> (Other modules can compensate for comnpromises in sensitivity but not 
> the Yamaha.)  The traditional remedy has been to insert a 250k pot 
> between the Pintech snare and module to tame the beast (like a 
> Guyatone cable, which has a rotary control built in). Do you have any 
> ideas besides use of the DTXpander--not that I want to discourage 
> anyone from using it, 

Ed,

I have been experimenting a bit more with the ConcertCast and have
settled on the following settings for now: Gain=99, MVel=1,
VelCurve=Hard 1.  The DTXpress seems to register small hits by showing
a percentage on the trigger display without actually making a sound on
the settings I had before.  These new settings seem to give a larger
dynamic range.  

On the DIY Edrums group someone was asking about a simple compressor
circuit, not specifically for the ConcertCast.  I posted a simple
circuit with 2 resistors and a diode which should do that.  I haven't
actually tried it, just simulated its effect with my design software,
but I could also post it here if you like.  I suppose I should try it
myself but I am incredibly busy at the moment and since joining one
band find myself almost in two bands which is getting complicated. 
That's in between ripping my kitchen apart trying to catch a stoat and
trying to earn a living (not as a stoat catcher it seems)!

Keith.

--- In DTXpress@yahoogroups.com, "Keith" <keith@...> wrote:
> I have been experimenting a bit more with the ConcertCast and have
> settled on the following settings for now: Gain=99, MVel=1,
> VelCurve=Hard 1.  These new settings seem to give a larger
> dynamic range.  
> 
> On the DIY Edrums group someone was asking about a simple compressor
> circuit, not specifically for the ConcertCast.  I posted a simple
> circuit with 2 resistors and a diode which should do that.  I haven't
> actually tried it, just simulated its effect with my design software,
> but I could also post it here if you like.  

Keith, 

This info should come in handy for people in similar situations. When 
I had a ConcertCast snare hooked up to an early DTXpress module, 
sticking tended to register at a high volume, regardless of the gain 
setting.  Straightforward hard rock drumming wasn't much of a problem, 
but music that demanded delicate grace notes and light syncopations 
definitely suffered. The module's inherent machine-gun effect 
exacerbated this lack of sensitivity.  A lot of people had the same 
experience over the years--hence the recommendation for the pot. It 
might be interesting for people with this snare and one of the Yamaha 
modules to revisit this issue again on the board and tell us what they 
do to cope, if anything--maybe try the parameters that you use, or 
approximations of it.

You're always more than welcome to post anything here that you'd like, 
and we can only be grateful for all of your efforts on the Magic Box 
et al. But we'll understand if you need to earn a living first. 

Always a pleasure,

Ed

--- In DTXpress@yahoogroups.com, "emf" <liberatusvirus@...> wrote:

> You're always more than welcome to post anything here that you'd like, 
> and we can only be grateful for all of your efforts on the Magic Box 
> et al. But we'll understand if you need to earn a living first. 
> 
> Always a pleasure,
> 

Well, I' post the files I put on DIY Edrums.  It was in answer to the
question

"Does anyone know a simple sechmatic (the simpliest please) to make a
passive compressor? My idea is to compress the signal from the piezo
before it enters the module."

My reply:

"I don't think you can make a "passive" compressor, unless you
consider a diode to be passive. I am not familiar with the DM pro, but
I have uploaded an idea for you to consider (Diode compressor) with a
simulated characteristic. Juggling with the resistor values will alter
the amount of compression."

Whilst the module in question was a DM Pro, it may be of use to
someone with a DTXpress, although I am not sure the circuit would be
doing anything that themodule cannot do using the VelCurve selection.

Keith.