Suggestions for a mobile power source for a guitar amp? Car battery, etc?

Elias Mason

Jun 10, 2017
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Hello. I am attempting to design a mobile set-up for powering a small guitar amp (19 watts). I have seen a few street buskers using a car/RV/boat battery and a power inverter, but my friend warned me that shuffling a car battery around is very dangerous and could result in burns or worse.

I am trying to keep the set-up (excluding guitar amp of course) under $200. Can anyone help a dude out?

Many thanks. I am totally novice and greatly appreciate your thoughts in advance!

-- Elias
 

duke37

Jan 9, 2011
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My inclination would be to dispense with the inverter and to power the amp directly from the batteries. This would save cost and increase efficiency. The amp would not need a heavy mains power supply.
Golf buggy/wheelchair batteries are safer than open lead/acid car type batteries. They should be safe if held in a box on a trolly.
 

Audioguru

Sep 24, 2016
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A 19W amplifier will need more volts than just 12VDC. A single-ended amplifier needs a power supply of at least 39VDC to produce 19W into an 8 ohm speaker. Maybe the amplifier is bridged then needs about 21VDC. maybe the speaker is 4 ohms then the current is higher so the voltage can be less. Maybe the amplifier uses class-D so the losses are less then the voltage can be less. Who knows?

You must find out the DC operating voltage of the amplifier, how loud you play it and how long you want a battery charge to power it.
 

duke37

Jan 9, 2011
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It is fairly easy to make a DC to DC invertor to give whatever voltage is required. My latest one was to give 350V for a transceiver.
I used a TV line output transformer core with one turn/volt and a couple of fets.
 

Elias Mason

Jun 10, 2017
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Jun 10, 2017
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It is fairly easy to make a DC to DC invertor to give whatever voltage is required. My latest one was to give 350V for a transceiver.
I used a TV line output transformer core with one turn/volt and a couple of fets.

Very good -- thank you for your input. The bottomline here is that I have a lot of reading to do! I am a novice, but there is no excuse to do some reading and figure out a functional set-up.
 
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