I'm sorry things didn't work out for you. Let's figure this out.
If you need to connect your T1® to an external system that requires an XLR input:
Run a line from the T1® Master Output to the input of the external system.
Use a 1/4" Tip-Ring-Sleeve to XLR cable or adapter.
What didn't work
Having a similar problem. I have to run the Tonematch to the house system via 2 XLR inputs near the stage, but I want to use my L1 Model II as my monitor.
I like to use my Model II on stage with me as my monitor too. That makes sense. Why do you need to send the signal out to two XLR inputs?
Last week I set up the system as usual and ran a 1/4" cable out of the Master output with a XLR splitter into the 2 inputs for the house. There was no sound coming out to the house. I then tried the Aux output with the same result.
Splitters can cause trouble and that trouble can be hard to diagnose because we don't know how the splitter is wired. It's hard to know how they are wired without opening them up to look or using a continuity tester.
If possible I avoid splitters unless I know exactly how they are wired.
Do I need a power supply for the Tonematch to boost the signal to the house?
No. And there's no way to attach the T1 Power Supply if you connect the T1® to the Model II Power Stand using the ToneMatch cable (the preferred method).
And if so, do I then run a 1/4" cable from the Master to the Aux input on the L1 system base?
Getting to the heart of things...
A single 1/4" Tip-Ring-Sleeve to XLR cable from the T1® Master Output should have given you a duplicate of the signal being sent to the L1® Model II.
Using a splitter of any kind would lower the signal output and could have reversed the polarity of the signals. If that happened, then you would get very little output or none.
Let's get back to this: Why do you need to send the signal out to two XLR inputs? If we can understand this, maybe we can figure out how to meet the need.