Ruby power supply - regulated?

[Aren]

I realize this is probably a stupid question, but I haven't actually any thread talking about that.
I just finished building a Ruby amp, and actually found a cheap speaker that sounds pretty damn good with it (an 8" full range speaker that "The Source" - our Canadian version of Radio Shack - had on sale for 9$). The thing is, I find that it eats batteries like crazy and figured I need to add a power supply.
The question is - will a regular 9V wall wart do the trick, or do I need to add a 7809 along the way? I was thinking of simply adding a filter cap across the leads.
I'm going part shopping tomorrow, so I want to make sure I'm getting everything I need.
Cheers,

Oren

[PRR]

Most power-amp chips are MADE to be used with crude unregulated supplies.

[Aren]

That was my assumption as well. Just wondering if anyone can confirm it specifically with regards to the LM386.

[bluelang]

it'll work.

[Aren]

Thanks!