Trying in vain to add an external boost pedal (TC Spark Mini) to my HX Stomp rig.  But I just can't get it working properly.
	 
	I'm running in 4CM, into my tube amp and I have an FX loop block in my HX Stomp's path (FYI my block path is pretty simple :  FX Loop L/R - Noise Gate - Delay - Reverb)
	 
	A few of things to clarify - 
	
		My goal is to get a clean volume boost - no added gain - and I want to use an external pedal, not the HX to boost the signal.
	
	
		WITHOUT the boost pedal plugged in, everything works absolutely perfectly.
	
	
		Plugging just the boost pedal into the front of the amp (and not using the HX at all) works perfectly
	
	 
	This is how it's wired up - 
	 
	
		Guitar --> HX Stomp IN
	
	
		HX Stomp OUT  --> Volume Pedal IN
	
	
		HX Stomp Send --> Front of Amp
	
	
		Amp FX Send --> TC Spark IN
	
	
		TC Spark OUT --> HX Stomp Return L/Mono
	
	
		Volume Pedal OUT --> Amp FX Return 
	
	 
	What happens is I get absolutely no signal - UNTIL I switch on the TC Spark Mini.  If I turn the Spark off, then I once again have no signal at all.
	 
	Have I wired things up incorrectly, or do I need to use a different type of FX block on the Stomp maybe?
	 
	Thanks in advance!
	 
	PS - I know I can set up a boost within the HX, but I want to use an external boost that I can tweak on the fly if necessary - I can just nudge the control with my foot whilst playing.