Noisy Jury-Rigged Daisy Chain

[devinbowie]

Hello,
Long-time forum lurker, first-time poster. Also, I am fairly new to electronics in general, I hope y'all can bear with me a bit if these are obvious questions.

I'm aiming to make a multi-channel power supply for my gear setup, tried the simplest route first, spliced a few 9-volt cables in parallel onto the cable coming out of a 2Amp 9v wall wart. Works great! Except for the hum. From what I've read, daisy chain power supplies always seem to add ambient noise to pedal chains. I've also read about sometimes being able to eliminate this noise by adding a filter capacitor on the wall wart output, but I'm having trouble understanding the exact logistics of where this would go, and whether or not it would actually help with this. I understand that these are not "isolated" power outputs, so maybe the cap wouldn't help.

I admit I'm taking a shortcut by not just building an entire isolated power supply unit. Still, I'm curious about whether there's a way to make this simpler unit work, mostly because of the timeframe in which I'm gonna need to use it (soon) but also because being able to build one of these things in some stranger's basement well would be so convenient if my power supply gets lost or broken on the road. Just grab a couple of wall warts, maybe a capacitor and do ten minutes of soldering.

Thanks for your help & experience.

[induction]

Did you try it on a single pedal without the daisy chain? It could just be a noisy adapter. Figure out which pedal is giving you the most hum, then unplug the rest of the chain and try the adapter on that one alone.

My rule of thumb is: unregulated adapters are noisy. I usually find that a daisy chain on a regulated supply is nice and quiet.

[duck_arse]

always, this:
http://www.muzique.com/lab/hum.htm

a cap alone may not cut it. you could put a resistor/cap filter PER spliced snap in a small box (will also protect the splicings, maybe some leds .....), tikkety-boo, 100%.