hi, so i made an array of 60 LEDs driven by 6 LM3915 (dot mode). they are driven by 2 audio channels which are each split into high-pass, band-pass, and low-pass via 2 state-variable-filters which are operating from a single supply. (everything is running of a +12V supply) the LED leads are fairly long so i've got a 10μF cap between pins 1 and 2 on each driver. i did observe the need for decoupling capacitors at the inputs, and presumably the outputs of the filters. but i've been plagued by some wacky DC offset kind of things at the inputs of the display drivers. when measuring with a scope, these levels gradually fall to about zero Volts, and then removing the probe, they climb back up again for some reason. i found elsewhere on these forums some recommendations for adding the peak-detection circuits which are mentioned in the datasheet. wanting to avoid extra work, i opted to try and clamp the audio signals with just a diode from pin 5 to ground. this didn't actually work with a 1n4148, but some germanium diodes i had kicking around worked really well. in fact they're performing some kind of peak-detection or averaging thing which makes the LEDs much brighter : ) and a resistor in parallel with the diode adjusts how quickly the peak hold reacts. well i'm not completely sure what's going on there actually, but that's how i'd describe it. (i think i saw something similar on a video circuit schematic once) my low-pass channels were making their LED drivers really quite hot, but a resistor between the +12V and the LED anodes seems to be keeping that under control for the time being.