After reading all your comments it sounds like you'd really prefer to just use a 12-volt automotive Poweramp and keep the cost as low as possible for this "one time use". If so, I'm thinking you could utilize several components you already own.
It'd be easy to simply cut one end off a guitar cord and wire it to an input of your power amp. If you found your Bass's signal was too weak to drive the power amp you could probably just plug in one of the pedals mentioned in your profile to boost the signal up a bit as necessary. (most any distortion type pedal should work nicely here)
I'd just borrow a 12 volt car battery (from your car or maybe a friends) to power the Amp, and then hook up what ever solar charging device you like. Even without recharging I'd think you could expect at least an hour of playing time from a good car Battery at reasonable volume levels.
Then you'd just need to fashion a speaker cable to connect the power amp to the bass cab you already own. It may not sound as nice as some of the previous suggestions but should serve your purpose at a very minimal cost.
It'd be easy to simply cut one end off a guitar cord and wire it to an input of your power amp. If you found your Bass's signal was too weak to drive the power amp you could probably just plug in one of the pedals mentioned in your profile to boost the signal up a bit as necessary. (most any distortion type pedal should work nicely here)
I'd just borrow a 12 volt car battery (from your car or maybe a friends) to power the Amp, and then hook up what ever solar charging device you like. Even without recharging I'd think you could expect at least an hour of playing time from a good car Battery at reasonable volume levels.
Then you'd just need to fashion a speaker cable to connect the power amp to the bass cab you already own. It may not sound as nice as some of the previous suggestions but should serve your purpose at a very minimal cost.
