I've got it all built, ready to put into the DMX controller.

But I've got a concern about doing this. The DMX chip runs off a 5V supply, my Teensy 3.2 only gives 3.3V signals.
I have got those 3.3V to 5V Logic Level Shifters, and I can relatively easily use one of those, the 3V3 side being fed from 3V3 off the Teensy, and the 5V being fed off the 5V from the DMX board.

But is this necessary ? My output signal is a high-low-high pulse, which I have set at 5mS (The one from the analog circuit was variable length, and not "clean" by any stretch of the imagination. I suspect the DMX chip has a PULLUP resistor on it's trigger pin, probably internal to the chip, which the analog signal pulsed to GND. If I were to feed that input pin with my 3V3 level signal through a 1K resistor I'm certain that would be ok, and no need for the level shifting device. I have seen this done before, and done it myself with a DFRobot Mini MP3 Player "Ready" signal (3V3) feeding an Arduino 5V input with internal PULLUP enabled, and it hasn't blown up yet.

Perhaps I should be asking this question in one of the other forums, but if anyone has any advice I'd be glad to get it.

Here's a dropbox video of it working with real music - I'm really pleased with the results......

 

For logic circuits powered by 5 V, the standard input voltage range for a logical "1" is 2.4 V to 5 V. Most 3.3 V logic chip output stages can meet this requirement, so there probably is not a problem with a 3.3 V circuit driving a 5 v circuit. The *is* a potential (!) problem with a 5 V circuit driving a 3.3 V circuit, because most 3.3 V jellybean logic chips cannot tolerate an input going above the positive rail voltage.

ak

 

Since the 3.3V output is marginal for the 5V input, I would be concerned about noise sensitivity and the low input voltage causing excessive current on the input circuitry.
I thus would use a level shifter at the output.
A pull-up may not be sufficient since the output circuit will likely clamp the voltage to the 3.3V rail.