Controls are even more important when you do it for yourself. Voice of sad experience here...
I agree. It was the best I could do by myself and I tried to setup controls.
The hacked Digidesign 442 a/b vehicle I built was controlled via c code. It would send a signal from the pc's serial port to a cmos logic circuit mounted inside the 442 that would switch between the two stereo pairs of opamps every x number of seconds using a random number generator and would write a time stamp to the screen whenever the switch was made. The code would then accept keyboard input and map my entry and the corresponding 1/0 value along with the timestamp and was written to a csv file that I could examine afterwards.
I could never get the switchover to be silent all the time, the analog multiplexers in the 442 liked to make random clicks when switching and this was distracting. My results were never consistent enough and after a few weekends of experimentation I moved onto something else.
Edit: The Digidesign 442 is a wonderful design and I bought a stack of them off of Ebay for a few dollars. The layout is really good and they are full of tight tolerance components and are a great source for either parts or a good starting point for experimentation.
Here's the pcb from one of the units I still have: