Skatepark Sounds?

[Dave the bass]

Now here's a non-valve related amp query.

A lot of 'da yoot' that come down our local skatepark have iPlods or an MP3 player of some sort as they love to listen to music while we all rip around the bowl and plaza.

I'm toying with the idea of building a simple IC based amp and speaker combo with a single 3.5mm input socket so they can plug their players in so we can all listen to one anothers 'sweet toons'. We've got no mains at the park so it'll have to be battery powered, I'm thinking along the lines of 1 or 2 rechargable 12V Gel filled batts so I could recharge them at home and bung 'em in my rucksack/skatebag and connect them up to the amp/speaker combo which I'd build in Ply. We've got a big metal building site style safebox that we keep brooms and sink plungers (to unblock the drains) that we could keep the 'boom boom box' in so it doesn't get chavved when it's not in use. Only those on the User group (6 of us) have a key to the box.

This doesn't need to be super-fi but being loud enough to cope in an open space and being 'reasonable-fi' is. I'm thinking maybe for each channel a full range speaker with a whizzer would be good idea, about 10" or so in a BR or IB box in ply with the amp built-in and just a volume control and single input.

Anyone built anything like it or got any advice? Suitable hi power/efficient chip? 12V or 24Volt?

Ta,

DTB

[Darren]

A car amp?

Unless you want to actually build something?

[Nick]

I would guess a digital amp of some sort would be the best bet for the highest efficiency.

[Dave the bass]

I would guess a digital amp of some sort would be the best bet for the highest efficiency.

Yup, that'd make sense, simple would be good too hence the chip based idea.

A car amp?

Unless you want to actually build something?

Thats a good idea Darren. I could strip the amp out or just bolt it speaker cab. I don't mind building it, either way to get us reasonable sounds down at the 'park would be good.

Whatever route I go down it's gotta be easily driven from the headphone socket of an MP3 player.

DTB

[Dave the bass]

Possible contenders.

LM1875n 20 Watt
TDA2050V 32Watt
LM3876T 56Watt

Just off to spec 'em up over lunch.

DTB

[Nick]

Remember though that getting more than 18w from 12v rails and 8 ohm speakers involves magic.

But I guess given efficient speakers you wouldn't need that much power.

[ed]

Yo the bass

I just read your post and mediately thought of ye olde outdoor pa system. If you could lay hands on one of those old trumpet type tannoys you could leave it up a pole or mount it on the nearest lamp post etc.....they were weather proof and often driven by batt powered amps ....and some of them actually had fidelity.....

just a thought

Ed

[Dave the bass]

Yo the bass

I just read your post and mediately thought of ye olde outdoor pa system. If you could lay hands on one of those old trumpet type tannoys you could leave it up a pole or mount it on the nearest lamp post etc.....they were weather proof and often driven by batt powered amps ....and some of them actually had fidelity.....

just a thought

Ed

Yeah I know the sort ye mean, lovely and efficient but the fing is though Ed they'd get stolen within hours. Some of the local 'yoot' don't embrace the same ethic as skaters and BMX'ers do and will do anything to upset the apple-cart, hence the idea of locking it away and keeping it small enough to bung in the box.


Point taken Nick, I'm now looking at TDA2030AV which I can bridge in each channel to get approx 20Watts or so on a 12v rail. Some of my ohter candidates were split rail +-24V Simple way out is TDA2003V which'll do approx 6 watts in 4R. Rapid do a cheap range of FR speakers 35-1404 is 8R but alledgedly 94dB efficient.

Still looking and thinking,

DTB

[al newall]

Dave.

I've got a couple of Ex. gainclone LM3875 chips bolted to heatsinks, if they are any use to you.
Usual terms apply.

[Dave the bass]

Dave.

I've got a couple of Ex. gainclone LM3875 chips bolted to heatsinks, if they are any use to you.
Usual terms apply.

Thanks for the offer Al but I'd have to faff with more batts to cope with the supply demands I think, according to National Semiconductor supply voltage range: |V+| + |V-| = 20V to 84V. I could muster 24V but 4 batts is gonna be heavy to lug down the park in a back pack methinks.

I'm meeting up with one of the doodes on Wednesday for dwinkies and run it by him before I go too far into it.

Cheers for the help Gents.

DTB

[Nick]

Something like a T-Amp would do the job if they are still about.

[Dave the bass]

Something like a T-Amp would do the job if they are still about.

Ooo, looks like it.

http://tinyurl.com/6mb45w

DTB

[simon]

Blimey Dave, it must be nice round your way. They'd have the concrete base, the gates and the trees too round here...

[Dave the bass]

Blimey Dave, it must be nice round your way. They'd have the concrete base, the gates and the trees too round here...

I've heard its a bit like that 'up there'

DTB

[pre65]

Hiya DTB-i had the opportunity today to accompany my dear old Mum on a coach trip to Londinium (i was the youngest one on the bus) to see the new St Pancras Eurostar terminal and also the London Transport museum at Covent Garden.

Whilst eating my sarnies in Covent Garden and watching the entertainers at work i spied one who was using a car amplifier hooked up to a motorcycle battery and then a couple of smallish "disco" speakers !!

This was controlled by what looked like a games controller of some sort.

As i was watching his performance i thought of your idea for the skateboarders.Something similar with a bigger (car ?) battery would probably do what you need.