I have completed two MK103 sound to light kits, and both work great. I powered them with a 9V wall transformer and replaced the microphone with a line-level input from my stereo.
What I want is one kit for each stereo (L-R) Channel to react independently of each other but with both kits connected to the same 9V wall transformer they act in unison - if I only have one channel connected to one kit, both kits will react, if both channels are connected both kits react simultaneously to the sound on either channel.
I did some searching and it seems that I need to isolate the power supply going to each kit, and I started experimenting with unity transformers but I guess I need pulsed DC to get the transformers to work. I’m not sure what that will do the way the kits function.
If someone can point me to a simple circuit that I can insert between the power supply and each kit that would isolate the channels I would greatly appreciate it.
Most likely it will work fine if you add two diodes to isolate the power supplies and add a say 470µF cap after each diode.
Please note that even with a complete separate system, the leds will flash more or less together, as there is a lot of ‘common’ in L and R audio…
I had actually tried adding a diode to the positive lead of each kit, but I’ll add a capacitor - I’m assuming that it goes between the positive and negative leads - and do some experimentation.
The amplifier I’m using is connected to my computer and there’s lots of YouTube videos to test your stereo so I know for sure which channel is being activated.
As a last ditch effort, I bought another 9V transformer at the thrift store last night, and I’m pretty sure it will work if each kit is connected to its own transformer - but I’d rather not do it this way, and I really want to understand how to fix this problem.
Update: I just added diodes and capacitors to each kit as you suggested and it works great!
I also tried it with just the diodes and that works too. I think when I originally put them in one of my solder joints must have failed. I have them on the breadboard now.