There may be more elegant methods to achieve what you want, but I'll explain my method of using the Triton for outboard FX.
-Enter the Global menu
-Switch to the 'Input/Sampling' Tab
-At the top left, switch input type to 'Analog'
-Set your input levels (See my note below on this)
-Set panning (I like to pan hard-left and hard-right when using both L and R inputs for FX processing on a stereo source such as another synth)
-Set BUS (IFX/Indiv.) to IFX1 for the inputs you're using (both, if processing a stereo signal) (See below for more info on routing!)
-Switch back to your Combis, Programs or Sequences
Now the input signal (your DX7/11) will be routed directly to the IFX1 of whichever Combi, Prog or Sequence you are currently using and will be mixed with any other signals going to IFX1.
You can substitute IFX1 on the Input/Sampling page for any of the 5 IFXs, the Valveforce tube (3,4 for individual mono signals or 3/4 for a Stereo signal using the valve as an insert effect) or alternatively you can choose L/R and then use the Send1/Send2 below to choose how much of your signal is going to the MFX1 and MFX2 in the current combi/prog/sequence.
I use this method in my live setup.
I play with a metal band and make use of my Triton as a ROMpler for Strings, Choir, Piano etc and for FX; while I use a Z1 for my leads/solos.
I use a Combi for my strings/choir and set the IFX and MFX as follows:
IFX1 - Delay
IFX2 - PitchShift
IFX3 - Delay
IFX4 - Reverb
IFX5 - Stereo Graphic EQ
MFX1 - Chorus
MFX2 - Reverb
Routing:
IFX1 -> IFX2 -> L/R Output (MFX sends at 127, 127)
IFX3 -> IFX4 -> L/R Output (MFX sends at 127, 127)
IFX5 -> L/R Output (MFX sends at 127, 127)
MFX1 -> L/R (Return at 96)
MFX2 -> L/R (Return at 115)
Valveforce used as final effect in chain.
The voices/progs of the combi are routed to IFX1, 3 or 5 depending on which FX I want for those voices.
My Z1 is routed directly to IFX1 as per my instructions above, and thus is affected by IFX1, IFX2; sent to MFX1 and MFX2 and routed through the Valve, then output at Main L&R outputs 1/2 on the Triton.
This allows me to do some interesting things with FX processing by merely changing which program or combi I'm currently using on my triton, without needing to change anything on the Z1, and still be able to use my Triton for its own synthesis alongside the FX processing.
Alternatively, I could use the 3/4 Outputs on the triton to return the FX-signal or to separate it from the main output of the Triton if I need to, but that requires separating the IFX on the Triton into their respective outputs.
Note on input volume:
Since the volume knob beside the input ports at the rear of the TEX is neither smooth nor linear and is prone to being accidentally moved when fiddling with cables at the rear of the TEX; I find it best to set it to the maximum value, and then set my actual input volume digitally on the 'Input/Sampling' page until I get the input levels I want (ie; no clipping or distortion).
Sorry for such a lengthy response, but hopefully that helps.
