Obviously the light bulb filiments are slower than leds, but it appears that they have it set to dot graph instead of bar graph. The green ones should remain bright while the yellow and red are coming on.

SSR’s can indeed be hellishly expensive if purchased retail, but I have always had good luck finding boxes of new ssr’s left over from industrial surplus. Nice thing is they are usually only 3-10 bucks each and can usually be found in reasonable to even large numbers of matching units.

There is no end of mayhem that can be accomplished with the careful abuse of a few of these!

i actually really liked the slurred responsiveness on the meter…. it gave it a little character rather than lights strictly going up and down

Ok, i get it now. it looks like if he used somthing to control the sample rate he would get a cleaner look to it using standard lightbulbs. the circuit is very basic he used for the example.

check this version out. much better…

http://homepage.ntlworld.com/michael.williamson5/xbox/vumeter/images/schematic.gif

solid state relays seem a bit overkill for driving lamps… it would be much cheaper and more compact to use plain old triacs…

http://www.simpleio.com/design/triacout/TriacOutSchematicNotes.asp

i also question the author’s comment on not using mechanical relays because they broke in a couple of days… he obviously did not use the appropriate relay for the task. in many cases, relays can be more rugged than solid state equivalents. mechanical relays also have lower contact resistance and capacitance, allowing them to better switch high current or high frequency circuits.

point being, mechanical relays still have a place in modern designs and won’t be going away any time soon. good article here: http://electronicdesign.com/Articles/ArticleID/2738/2738.html

I agree both relay types have there place. but it would be stupid to make this with mechanical relays with the rapid switching rates that a SSD can handel.

… not to mention the sound.

Imagine the noise all those mechanical relays would make switching on and off so quickly?

looks like a really complex color organ

The wiring IS clean. Good job guys – Just because it’s a hack doesn’t mean it can’t look professional.