I wanted to run the Roland Cube 10GX amplifier by a battery for my cigar box guitar.
As with most Roland stuff, this amp has some great tones, will get very loud and costs $129. The Roland Cube 10GX is normally powered by a 5.7 volt DC/120 volt [USA] wall transformer.
I have been powering my guitar pedals, small mixer, and Roland Micro Cube amps with LiPo batteries that are primarily used for Radio Controlled electric motors. The small LiPo batteries come in multiples of a specified voltage of 3.7 volts per cell and have to be charged with a LiPo battery charger. The cells are actually charged to 4.2 volts. I have never found an explanation for why LiPo batteries are specified at 3.7 volts per cell.
Anyway, I have been using a two cell, 2.2 amp-hour LiPo battery, charged to 8.2 volts to power my 9 volt guitar stuff and all seem to work fine. This is very economical since the batteries can be charged over 1000 times, are not very expensive and have several times the capacity of a regular 9 volt disposable battery. I think a typical 9 volt non-rechargeable battery has about 0.5 amp-hour capacity.
I recently bought a Roland Cube 10RX hoping to power it with one of my LiPo batteries. Well, a 4.2 volt battery is too low and a 8.2 volt battery is too high. I discovered a "DROK LM2596 adjustable voltage regulator" that would reduce the 8.2 volts or any other DC voltage up to 40 volts, to the 5.7 volts DC required by my Roland Cube 10RX. So, it could be used with any 12 volt battery and can handle up to 2+ amps. There are other voltage regulators out there that can handle more than 2 amps, if you need it. Also, the regulator has a digital readout to show either input voltage or output voltage which is also handy.
To connect the battery to the voltage regulator I used a battery connector with pig tails. If you were not going to use the battery for other stuff, you could cut off the battery connector and connect the battery wires directly to the voltage regulator. I ordered a 2.1mm power connector that fit the amp with pigtails. Connect the battery to the "In" of the voltage regulator and the 2.1mm connector to the "Out" of the voltage regulator. Plug the battery in and adjust the output voltage with the little adjusting screw.
I haven't decided how to attach the battery and regulator to the back of the amp. Maybe just Velcro or stuff in a bag and hang from the back.
My Roland Cube 10GX is the loudest, best sounding battery powered guitar amplifier I have yet discovered. It is a 10-watt guitar amp with custom-designed 8" speaker Three preset COSM amp types: Clean, Crunch, and Lead which can be replaced with 10 other custom COSM amps via the free CUBE KIT app for iOS and Android devices.
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this is why I love this hobby and board, necessity is still the mother of invention, and so many great things are begun with the question "Well why couldn't I...?) great stuff and ideas to stay busy for years.. thanks!
Sounds like a great solution for a lot of applications. The data sheet for the LM2596 makes it sound pretty easy to set up. Does it need a heat sink?
Tom,
No heat sink is needed for powering the Roland 10GX. My voltage regulator doesn't even get warm. It's the "Buck" type which is pretty efficient.
The voltage regulator came assembled on the circuit board. They are very inexpensive on Ebay.
I do use the LIPo's for a lot of applications. They make round ones that look like could be directly substituted for round batteries. I haven't gotten one of those. I already had all of this stuff from RC electric flying.
The chargers are a little investment. I got a nice USA made cell balancing one 5 years ago. I think a good one can be had for $30. The battery savings are remarkable.
I see what you mean by inexpensive.......
Under $5.00 including shipping on ebay. And that includes a digital voltage readout. That's just amazing.
A small wet cell motorcycle battery should keep you playing for days without a recharge.
I used to fly RC planes so I am familiar with those battery packs and the charger. Still have it in a box some place.
Thanks for all the useful information.