Battery powered amp

[Shpoop]

Hey guys...I'm interested in knowing if there are any battery powered amps around (not car batteries, normal alkaline batteries).

When I search "battery powered amplifiers" on google, all I get is guitar-style amplifiers...I just want to amplify a signal then output to other speakers.

I know there are these headphone amp thingies, but they dont put out anywhere near enough power. I'm looking for something that puts out on the order of 100W (it would be powering EJ Jordans...I know, most of you will find that a wasteful use, but just humour me...)

I know ~100W is a long shot on batteries, but I figured if anyone knew of something, it would be one of you. So anyone got any ideas?

Thanks!
Matt

[Buckapound]

Do some research on Class D amplifiers, especially the many flavors of TriPath amps such as the Sonic Impact and kits from 41hz. It's a whole universe of amplifiers especially well suited to battery power as they are highly efficient. Sound great and fun to build or modify to boot.

Get reading. Plenty of info over on the Class D forum and elsewhere on the Web.

--Buckapound

[jeff mai]

100W into 8 ohms. Do the math. It adds up to a lot of batteries.

[Speedskater]

UPS batteries are the way to go.

[chipco3434]

D cells?

Only if you don't like to listen often or you work in a battery factory. Start with 24 batteries and tell us how it works out.

[neutron7]

100W peak. maybe. you should probably aim a bit lower and have very efficient speakers. maybe you could use quick charge batteries from RC cars or cordless tools.

Definitely go with digital amp. it would save quite a bit of power waste.

is it for some kind of uber boom box?

[RAYSIMMONS]

Final labs.http://www.positive-feedback.com/Issue1/final.htm

[AndrewT]

Hi Shp,
a few questions.
q1. what efficiency/sensitivity are your proposed speakers?
q2. what is the average SPL and peak SPL you want to achieve?
q3. what life would you expect from the batteries before recharge or before disposal (due too many recharges)?
q4. what power/energy could you save by changing to more efficient/sensitive speakers?
q5. what voltage does the amp need?
q6. how do you obtain the Vrail voltage? smps or series batteries?
q7. do you want the extra overhead of maintaining dual polarity +-Vrail or the simpler and more efficient single +Vrail with the slightly more complicated amplifier?

Now, consider the quiescent current that the amplifier draws. Some are surprisingly large. If it needs a cooler then it consumes too much for battery power.
Consider the power difference between 90db/W speakers and 100db/W speakers.
Consider the difference between 100db peak SPL and 97db peak SPL.

[Speedskater]

I wrote use UPS batteries.
But after thinking about it.
Just use a UPS unit. Disconnect the buzzer. If you have loudspeakers, size and weight aren't the biggest factor. When the battery wears down just plug it into an AC outlet. And you have a UPS unit the rest of the time. And, and you can use any little AC powered amp.