Battery-Powered Bass Rigs

[Aalin]

Yes, don't know if it's 100 W under 8 or 4 ohms

[Count Bassie]

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[tauzero]

I've got a Hotone Thunder Bass and was given a 4000mAh USB power bank for Christmas, plus I'm almost at the end of building the house jam micro cab. So I've just ordered a couple of step-up modules from Ebay (a fiver for two) so as to experiment and see if I have the perfect ultra-portable rig.

[Happy Jack]

3 minutes ago, tauzero said:

... was given a 4000mAh USB power bank for Christmas

But what can you get from the most powerful output on the power bank? Does it have a single socket that can deliver >1A?

 

[tauzero]

8 minutes ago, Happy Jack said:

But what can you get from the most powerful output on the power bank? Does it have a single socket that can deliver >1A?

 

 

1A - enough for POC purposes. I've got a couple of 18V packs for a cordless drill which could be pressed into service too, I think it would just need two spade terminals to a DC power connector.

[JohnH89]

I am using , when needed , a 35W class D module from ebay for a fiver , from an 18v power tool battery , intlo a PJB C2 cabinet . I bought a Hotone nano bass to use as a preamp but there was no need . A fine sounding little amp that is easily transportable . A 2000mah battery has been tested and was still working 4 hours later . To change the battery takes seconds . This has nowhere near the power of the Briefcase but the battery lasts a hell of a lot longer . This was designed to play a gig that is about an hours walk from the public highway , so the fact that it is a quarter of the weight of the Briefcase is a bonus . I will see if I can dig out some photos and post them here if I find them .

[JohnH89]

Original build was with TDA8932 . Mk2 was built with TPA3118 which is 60W at 24v into 4ohm . I think it was 35w at 18v into 8ohm . On recommendation from contributors , mk2 was built with fused power supply . Output is bridge tied load so needs to be an insulated jack . I used my PJB HA1 as a preamp and later the Hotone nano bass . Now I use it straight from the bass as it appears not to need a preamp . 

Here are a few photos .

[Happy Jack]

That's a very cool micro-rig. 

 

Do you offer a build service? 😉

[tauzero]

On 17/05/2022 at 21:22, Smanth said:

A timely revival!

 

To date I've been using a Roland Microbass Cube, which runs off 6 rechargeable AAs for a few hours.

But

Somewhere in the package delivery systems an Ashdown Ant and an Stonefield Mighty Mini.

Add in an HX Stomp and a prototype home built Midi pedal ... at present the only thing that is not dependent on the mains is the Midi pedal (Internal Lithium Battery).

 

The band is a ukulele group and we sometimes do gigs outdoors ... and I've just started researching how to drive my system from a portable rechargeable source.  It turns out that many modern rechargeable power banks (the ones that support quick charging) can be "told" by whatever they are plugged into what voltage/current to provide, the range is quite amazing!

 

 

I imagine this would nicely drive your micro head setup.

 

I'm hoping that I can get it to drive my setup (Tho I'll have to do some mods to the Ant as it has an internal mains transformer)

 

I've yet to find an off the shelf widget that sends the "Give me more power" command to the battery bank, but if I do I'll share it here.

 

The specs I've read means a self-build is not too challenging and should have a price point of just a few quid.

 

I think this may be the widget you want: https://www.electronics-lab.com/simple-adapter-board-turns-usb-c-power-supply-variable-voltage-source/

 

So it would be possible to fit a USB-C power bank, one of these boards, and a TPA3118 into a micro cab, with a USB connector and a jack socket on the back panel, and have a portable powered speaker. And a switch to allow switching between active and passive.

[JohnH89]

5 hours ago, Happy Jack said:

That's a very cool micro-rig. 

 

Do you offer a build service? 😉

No mate . Life is too busy . If you can solder a jack plug together and drill a hole it is not beyond you .

 

5 hours ago, tauzero said:

 

I think this may be the widget you want: https://www.electronics-lab.com/simple-adapter-board-turns-usb-c-power-supply-variable-voltage-source/

 

So it would be possible to fit a USB-C power bank, one of these boards, and a TPA3118 into a micro cab, with a USB connector and a jack socket on the back panel, and have a portable powered speaker. And a switch to allow switching between active and passive.

I do have a plan for the future that is similar to this . I was going to build a micro version of my Markbass 801 , using a 6in speaker , DIY rear ported cabinet and a class D board . I was going to stick with the power tool battery as they can be changed quickly , are easily replaced and I have a load of them . A spare can be tucked in a pocket . I reckon 4 of them would do you for 24 hrs play time .

I fed the original into a high efficiency 12in 4ohm cab and was astounded by the volume . I think a 4ohm 6in driver with 95dB at 1W/m would be more than loud enough . 

Regarding the active/passive switch , I have found it to be unnecessary . The amp will work fine with a passive . If active overloads it , which it didn't when I tried it , just back off the volume on the bass .

Edited February 15, 2023 by Wally Gogg

[tauzero]

3 hours ago, Wally Gogg said:

I do have a plan for the future that is similar to this . I was going to build a micro version of my Markbass 801 , using a 6in speaker , DIY rear ported cabinet and a class D board . I was going to stick with the power tool battery as they can be changed quickly , are easily replaced and I have a load of them . A spare can be tucked in a pocket . I reckon 4 of them would do you for 24 hrs play time .

I fed the original into a high efficiency 12in 4ohm cab and was astounded by the volume . I think a 4ohm 6in driver with 95dB at 1W/m would be more than loud enough . 

Regarding the active/passive switch , I have found it to be unnecessary . The amp will work fine with a passive . If active overloads it , which it didn't when I tried it , just back off the volume on the bass .

 

I should clarify on the active/passive thing - I meant how the speaker is used rather than what sort of bass is going in, so the speaker can be connected either to an external amp or use the internal board. Using a USB power pack, it would be possible to leave the power pack permanently in the speaker and have a USB connector to charge it.

 

[nekomatic]

9 hours ago, tauzero said:

 

I think this may be the widget you want: https://www.electronics-lab.com/simple-adapter-board-turns-usb-c-power-supply-variable-voltage-source/

If I understand correctly what that board is doing, it isn’t changing the voltage itself, just requesting your choice of voltage from the USB-C supply via the ‘power delivery’ protocol. Not all supplies support all power delivery voltages though, so if you have a rechargeable power bank with a USB-C socket on it it may still only be able to put out 5 volts. 

[tauzero]

8 minutes ago, nekomatic said:

If I understand correctly what that board is doing, it isn’t changing the voltage itself, just requesting your choice of voltage from the USB-C supply via the ‘power delivery’ protocol. Not all supplies support all power delivery voltages though, so if you have a rechargeable power bank with a USB-C socket on it it may still only be able to put out 5 volts. 

 

That's right, and that's what @Smanth was after. You can get DC step-up converters (I've got one coming for my ordinary USB power bank) or get this which will operate on multi-voltage USB-C power banks and request a specific voltage. Which is also all covered in the video on the linked page.

[nekomatic]

3 minutes ago, tauzero said:

Which is also all covered in the video on the linked page.

Fair enough, I confess I didn’t watch it. 

[Happy Jack]

 

[Happy Jack]

So ... what happened next? Well that busking gig got cancelled at short notice (the guy is much younger than me and had family duties on the half-term) so there was a 3-week delay before I could join him and a friend on congas this last weekend. 

 

I don't know where you live, but around here Sunday was barely above freezing and absolutely NOT ideal busking weather.  The guitarist was playing with his teeth quite literally chattering throughout and his fingers refusing to obey his brain.

 

Also, I forgot my 'dead cat' for the mics on the Zoom H4 and it turned out to be far windier than I'd expected, so the sound quality wasn't great.

 

Bit what the hell? Could you hear the GR Pocket 50 in a busy-ish market, up against a guitar using a battery Orange Crush 30 and a pair of mic'd up congas going through a mini-tower batter PA?

 

[Happy Jack]

 

[Happy Jack]

I reckon that's a Yes.

 

I played two truncated sets ... 11:30 - 12:00 and 12:15 - 12:45. By my standards that's a very short gig, but the key thing is that after pumping out more-or-less full power for an hour I still had two of the three blue LEDs lit on the Pocket 50.

 

These things are rarely linear and I doubt that means it could keep up that output for three hours, but I'd be pretty confident that it could handle at least two. Besides which, assuming a 3-set gig then that's 2x15-min breaks in which to retire to the pub and plug in the recharger.

 

And, of course, batteries respond poorly to the cold. On a warmer day - or at least a milder one - I imagine that the battery would anyway last longer.

 

So far so good.

[Clarky]

On 06/03/2023 at 16:26, Happy Jack said:

 

Since when did you become a Russian Cosmonaut, Jack?

 

But seriously, props for braving the elements ... and what is that unusual-looking (travel?) bass?

[Happy Jack]

18 minutes ago, Clarky said:

... and what is that unusual-looking (travel?) bass?

 

https://snap-dragon-guitars.com/products/snap-dragon-e-bass

 

Bought for me by @Silvia Bluejay after seeing the guitar version being wielded by @MacDaddy

 

Devilish cunning, and very playable.

[BassmanPaul]

You know Jack, I'm glad you're happy and all BUT, every time  I see your dancing icon I think there's a bug crawling on my screen!! LOL

 

Thank you for the gig video. It did my heart good seeing the big red busses trundling behind you.  It's funny what you miss when you're away from your home country or city.