Triggered
Of interest perhaps. Easy build . My own cludged design .
4 x latching switches. So, 4 x trigger inputs and 4 x i/o . Not tested with audio, but clock, pulse signals only . Please feel free to give a better description. Pulse inputs latch the on/ off states of each channel 
For each channel the i/o is interchangable.
Yes that is a 7806 regulator ā¦ for some reason ,I think this is explained in the videoā¦Iām not a ārealā engineer.
Itās me or thereās something strange on the stripboard with the led 1 connection ?
Whilst not attempting to give a comprehensive guideā¦ just a snapshot from a working layout. The layout creator doesnt have led symbols 
sometimes I use a resistor labelled as led , but not in this case .My bad.
So yeah a load resistor and led to gnd. Hope that clears that up for the less inititiatedš
Why not just power the chips off the +12 V rail?
As it is, Iād add diodes to protect inputs and outputs against overvoltage.
That is true , howeverā¦Soz ā¦ should have said in my introā¦it is what it is. Been following Sam for 4 yrs since synth bike. Iām sure Sam has some non protected builds and whatnotā¦so if its good enough for the gooseā¦
ā¦ kind of how I roll. Just some non commercial DIY ā¦
Anyway shouldnt be making excuses , check out my unapologetic user name ā¦thanks for having a gander 
Edit ā¦ cant remember why not 12v ā¦either incompetence or something to do with trigger levelsā¦
