Re: MIDI 101 - Yamaha DTX700 - Help
The most basic error that a lot of people that are new to MIDI make is an assumption that MIDI carries audio. MIDI does not produce any sounds of its own - it is purely a data link.
MIDI sends a series of numbers (channel, note length, velocity, note value and (sometimes) aftertouch) to an interpreter that then turns that data into audio. The conversion can take place inboard (e.g. in your Clavinova - lovely electric piano by the way) or can be sent to an external interpreter, as Shedboyxx points out.
If you want to trigger sounds using the module on your Yamaha there is no reason why you couldn't. MIDI out on the Clavinova to MIDI in on the Yamaha unit. You could even do this the other way around so that the drums trigger the sounds on the piano. The main problem that a lot of new users run into here is setting the right MIDI channel on the MIDI receiver.
MIDI uses data channels (like channels on a mixing desk) because it is designed to be used on a number of different devices at once, linked together.
Theoretically, you could daisy-chain your piano to your drums and then into another device (say, a synthesiser) and if the channels were set up correctly then only be able to trigger notes on the piano from the drums, even though the data is sent to two external devices.
What you need to do is to make sure that the Yamaha unit is set to receive MIDI on the right channel. Check the MIDI output channel on the Clavinova (probably defaults to channel 1) and set the drums to receive the same channel. Percussion is usually set to channel 10 by default so it's likely that your Yamaha unit is set up to receive from channel 10. Change it to whatever the default output on the Clavinova is (probably channel 1) and you'll be good to go.