Battery Powered Bass Amps

[stewblack]

4 hours ago, Caz said:

Hi, sorry to resurrect such an old thread. I'm on the lookout for a way to battery power a small Genz Benz or medium sized Mark Bass amp, and some of the links here like the Maplin battery pack are no longer active. For people who do this regularly, just wondering is getting a battery amp the way to go or is it better to get a decent battery pack for my regular amps? If the latter, any recommendations please for which is best for this purpose? It's just to play outside with people, busking or little jams for fun with drums. Ideally not looking for a massive generator that could do a full band/PA system, just enough to get a working bass amp.

Thanks,

Caroline 

Hi, I think the Phil Jones stuff is highly regarded, but definitely not cheap! 

[Mottlefeeder]

I have an Ashdown MyBass mk1 500w amp, and I can run it from a 'modified sine wave' invertor rated at 300 W. The invertor has a continuous rating, and the amp is never used at full power, so it works. That setup draws about 2 Amps from a lead acid battery, so for a half-brick-sized 7AHr battery you can expect 2-3 hours of use before the voltage droops and the invertor shuts down.

That type of invertor uses a very crude approximation to the mains waveform, and it is rich in harmonics, so it may cause a buzz through your gear, and it may invalidate your amp warranty if you have a problem. A better solution is a pure sine wave invertor, which does not generate a buzz, does not invalidate your amp warranty, but costs a bit more, £80 vs £30 for a modified sine wave invertor of comparable power.

An alternative would be to buy a car stereo booster amp for about £50 and run that directly from the battery. Current designs from the reputable manufacturers will deliver 150 W into 4 ohms, or about 75 W into 8 ohms. An active bass will provide enough output to drive it directly (but not drive it to full power - for that you will need a booster, or an FX pedal with some gain).

Something like https://www.caraudiocentre.co.uk/product_m-pioneer-gm-a3702_p-40132.htm would probably do (mine was a Kenwood, no longer in production), but you would need to check the maximum sensitivity was about 200mV. 

Anything complying with CES 2006 will specify RMS values, regardless of what the marketing department painted on the lid or put as a headline.

David

[Dan Dare]

Good advice above. You really need a pure sine wave inverter if you go that route.

[stewblack]

There's a guy on YouTube playing through a battery powered Roland PA and it's sounds just fine. 

Ordinary AA batteries too. 

[Caz]

Thanks for these helpful replies. It's looking ideal to use the regular amps with a battery and pure sine inverter. Can anyone who uses a setup with a pure sine inverter and battery please recommend which ones you use? And which type of battery you use? They don't look cheap so looking for something that will definitely work on either a small or medium sized amp.

I've read it'll need a deep cycle battery but Mottlefeeder uses a lead acid battery, I'm a bit stumped and not sure which is the best to go for.

[Mottlefeeder]

1 hour ago, Caz said:

Thanks for these helpful replies. It's looking ideal to use the regular amps with a battery and pure sine inverter. Can anyone who uses a setup with a pure sine inverter and battery please recommend which ones you use? And which type of battery you use? They don't look cheap so looking for something that will definitely work on either a small or medium sized amp.

I've read it'll need a deep cycle battery but Mottlefeeder uses a lead acid battery, I'm a bit stumped and not sure which is the best to go for.

Lead acid batteries refer to the basic chemistry, in the same way that 'alkaline' or 'Lithium something or other' does. Lead acid technology is heavy, but also considerably cheaper than the other options. 

Within the family of lead acid batteries there are minor differences in design depending on what the battery is intended to be used for. Car starter batteries are intended to be kept fully charged unless they are cranking the engine but golf cart batteries are intended to be run down to 'empty' and then recharged. Batteries designed for discharge and recharge are known as deep cycle batteries.

Using the wrong battery will not damage the rest of your gear, but it will result in the battery having a relatively short life.

David

[machinehead]

5 hours ago, Caz said:

Thanks for these helpful replies. It's looking ideal to use the regular amps with a battery and pure sine inverter. Can anyone who uses a setup with a pure sine inverter and battery please recommend which ones you use? And which type of battery you use? They don't look cheap so looking for something that will definitely work on either a small or medium sized amp.

I've read it'll need a deep cycle battery but Mottlefeeder uses a lead acid battery, I'm a bit stumped and not sure which is the best to go for.

And if you do use a deep cycle or leisure battery, don't discharge it below 50%.  Doing so will significantly shorten its life span.  To check this you need a cheap multimeter (£10).  As a rough guide, measure the voltage when fully charged (but wait for a day after charging before measuring, to allow the voltage to settle), then don't discharge more than 0.5 volt lower than the fully charged voltage.  It's not as complicated as it sounds.

Frank.

[Caz]

Ok great, that's all good to know, thanks. So does anyone have a battery setup that works with the pure sine inverter that could say specifically which items to buy please? 

This is for a Markbass F1 and 2x12 cab, have smaller cabs too that could be used if the bigger one is an issue, but I'm now ideally aiming to be able to gig properly outside given the recent government guidelines.

Caroline

[Caz]

Hey, just to give an update, I settled on a Behringer battery powered PA speaker with a bass pre-amp. I asked around and a few double bass players use these for outside gigs so thought I'd give it a try. So far really happy with it, apparently the battery lasts up to 12 hours, and it has a second input as well as a bluetooth function to pair with a microphone or MP3 player. Jamming with a drummer outside tomorrow so will see how it goes. It doesn't deal with the lowest notes on my 4 string Precision too well at a really loud volume, but at only £139 can't ask for too much.

It even comes with a mic and cable  https://www.thomann.de/gb/behringer_mpa40bt.htm

[bumnote]

On 22/07/2020 at 17:23, Caz said:

Hey, just to give an update, I settled on a Behringer battery powered PA speaker with a bass pre-amp. I asked around and a few double bass players use these for outside gigs so thought I'd give it a try. So far really happy with it, apparently the battery lasts up to 12 hours, and it has a second input as well as a bluetooth function to pair with a microphone or MP3 player. Jamming with a drummer outside tomorrow so will see how it goes. It doesn't deal with the lowest notes on my 4 string Precision too well at a really loud volume, but at only £139 can't ask for too much.

It even comes with a mic and cable  https://www.thomann.de/gb/behringer_mpa40bt.htm

How was the Behringer on the jam

 

[Caz]

Really good I thought. I've kinda gone off topic on this thread and ended up getting something different from what was being discussed so I'll start a new thread for anyone looking into battery powered PA speakers. Thanks again for the help.