Yamaha DTXpress/DTXplorer/DTXtreme

So far as sheer number of inputs goes, your plan would work. 
However, be forewarned that whatever you subsitute for the Yamaha 
snare won't get the three advertised voices, which may not be a 
concern for you. But what you might not realize is that the Roland 
PD-80R mesh pad, nor any other mesh pad for that matter, will even 
provide two voices through the standard DTXpress II's snare input 
(#2). The reason is that the rim triggers that provide the multiple 
voices on the gum rubber TP65S smare are FSRs, whereas the rim of 
the Roland, or any other mesh pad, is a piezo. Most people who swap 
the Yamaha snare for a dual-zone mesh snare plug the body of the 
drum into #2 (technically called a stereo, not dual-zone, input), 
thereby losing the input's rim switch capability, and the separate 
rim sensor into either mono #9 or mono #10, which are accessed via 
the same single TRS jack with the appropriate insert cable. If you 
did so, you'd have to give up your fourth tom or your third cymbal, 
since one of your extra mono inputs would be taken by the snare's 
rim.

Let's assume that this sacrifice is worthwhile for you. The next 
issue is the PD-80R itself. For one thing, I've heard that its rim 
does not trigger with much authority through Yamaha electronics, 
though I can't verify it myself. Another consideration is that it is 
only 8" in diameter. Many people who upgrade their snares do so, at 
least in part, to get a bigger target to hit. More on that point in 
a minute. My biggest problem with the PD-80R is that, like all of 
Roland's equipment, it is too expensive for what it does. To my 
mind, you owe it to yourself to check out the Pintech ConcertCast 
dual-zone mesh pad, which measures two more inches in diameter than 
the PD-80R and provides the same triggering technology. I, and many 
others, can assure you that it works perfectly well with the Yamaha 
module, as long as you split the body and rim as I explained above. 
It would also save you approximately $150. Another alternative from 
Pintech is the AX14S, which, at 14", would save you $70 or so over 
the smaller Roland. Bear in mind, however, that for either of these 
alternatives, you might want to consider using a separate snare 
stand, rather than mounting directly on the rack. Not only would you 
have more control over position, but also less problem with 
crosstalk.

--- In DTXpress@yahoogroups.com, "isidorelechat" <renaudmarin@h...> 
wrote:
> Hi,
> 
> I have been out of the drums world for ten years (I am 31 now) and 
> after trying a td-6 and td-8 recently, I have decided to buy a kit 
as 
> the sounds and feel of e-drums nowdays are far better than the 
> previous ones I have tried. After checking the other available 
> systems, I became interested in the dtxpress II.
> 
> I am planning to go for the following setup and would like first 
to 
> get confirmation from you that the extensions I want to add will 
fit 
> within the available inputs:
> 
> Snare: I would add a Roland PD-80R
> Hi-Hat pad: I would use the orginal dtxpress 3 zones snare pad
> 4th tom: I woud use the original hi-hat pad
> Extra cymbal: I would probably buy another yamaha one
> 
> Thanks for your help