/diy/ - Do It Yourself

Hey guys. Never knew about this thread, but I like it. Electronics are the shit. I've got a few questions for you.

How much should I expect to spend on basic lab equipment like a scope, function generator, and variable voltage supply?

This one's more in depth. How can I use an audio waveform to control LEDs without a microcontroller? I've got an active LPF planned to filter everything but bass, with the intent that a strip of LEDs will briefly turn off on bass notes. I'm planning on running the LED supply through a transistor which will be controlled by the filtered audio.

What I'm worried about right now is that the peaks are too quick to set them as a threshold, because if I did that the lights would flicker too briefly. If I don't have a high threshold, they'll turn on and off too rapidly, whereas I want it to be more like one cycle per bass note. What's the alternative? I was thinking I could use a 555 and have it output for a little while after a high peak, covering a typical length of a beat, but that seems like overkill. Maybe something simple with a capacitor and diode or something? I'm not sure.

As an example, this is the waveform of Kanye West's "Fade" around 33 seconds. Check it out on youtube or whatever and skip to that time - it's very bass-heavy, but the waveform is still too complicated to simplify have it gate a transistor. The lights would be flickering too quickly to even see, instead of a nice pulse on each beat.