Tech: 12v sterio amp

Subject: Tech: 12v stereo amp
From: harpmaker
Date: 17 Feb 03 - 10:27 PM

Does anybody know if such a thing exists?

Subject: RE: Tech: 12v sterio amp
From: open mike
Date: 17 Feb 03 - 10:54 PM

so you can plug your stereo into your car?
sure lots of stereo equip built to use car
electricity...and lots of 12 v equip made
for r.v., boat and vehicles as well as
alternative energy house...solar panels, etc.

Subject: RE: Tech: 12v sterio amp
From: harpmaker
Date: 17 Feb 03 - 11:17 PM

But would these loony car things provide 30/40w RMS per channel? Dont think so somehow. They may say; 120w total music power, but, in reality, its as weak as a wet blanket on mothers day. Or, yea I could go on....SO...........?

Subject: RE: Tech: 12v sterio amp
From: harpmaker
Date: 17 Feb 03 - 11:42 PM

Ohh, I do sound awfull, but the reality is, I can' find anything to fit the bill.

Subject: RE: Tech: 12v sterio amp
From: John J
Date: 18 Feb 03 - 12:06 PM

Most solid state (ie not valve...or tube if you're from t'other side of the Atlantic) amplifiers run on low voltage, albeit derived from mains voltage. If you can find a mains amplifier that has an INTERNAL power requirement of 12V, it's a fairly simple procedure to disconnect the mains power supply and supply the thing with an external 12V supply.
If you're not technically competant or confident, try asking at a local TV / Radio repair shop (or a competant electronics enthusiast).

Cheers,

John

Subject: RE: Tech: 12v sterio amp
From: Dave Bryant
Date: 18 Feb 03 - 12:22 PM

Car booster amps can produce quite a lot of power - I use one for some small open air busking-style venues and it's not bad - but to get the most out of them use 4 ohm speakers.

The easiest way is to use your mains PA running from a car battery via an inverter. These are getting very cheap these days - I bought a 300w one for about £30 recently. Obviously if you were running it at a steady 300w, you'd be dragging in the region of 30a from the battery. In fact the average power required by an amplifier is usually only a fraction of it's rated power which is only reached for momentary peaks. These peaks are averaged out by the large smoothing capacitors in the power supply, so a 300w inverter can supply an amplifier with quite a higher peak output.

You just attach the inverter leads to a car battery and plug into the mains socket.

Subject: RE: Tech: 12v sterio amp
From:
Date: 18 Feb 03 - 06:38 PM

harpmaker, what sort of requirements are you talking about? Most Stereo amplifiers for cars can handle the power you say, but do they have the inputs you need?

Subject: RE: Tech: 12v sterio amp
From: John in Brisbane
Date: 18 Feb 03 - 08:30 PM

TOA make a range of industrial PA amplifiers designed for schools and factories etc. I have a mono 60W version which is designed to run on both 12 Volts and mains power - the battery presumably being there to cope with failure of the main electricity supply.

They're heavy and rugged and clearly not meant for everyday vehicle use. I use mine coupled to a very large Yamaha monitor speaker for PA use when mains power is not available - I use a 12V deep cycle truck battery which I use with an electric outboard or for camp lighting at other times.

The quality and volume of sound is seriously good, particularly when compared to the general offerings for portable PA's for school use.

Best of all you can pick up TOA's and similar for a song at liquidation sales for restaurants and warehouses. (12 Volt ones aren't that common however). Don't be put off by the mass of terminals on the back of the amp that read 70V or 100 V outputs, just use the 4 ohm or 8 ohm speaker terminals.

I don't kmow whether TOA or others make stereo amps - stereo is probably not appropriate for permanently installed multi speaker premises.

Regards, John

Subject: RE: Tech: 12v sterio amp
From: Dave Bryant
Date: 19 Feb 03 - 04:29 AM

When I use my car booster amp, I use a small mixer which besides allowing me to use up to 4 inputs, also brings the signal up to line input level (.5v-1v). The amp itself is rated at 160w total peak power, this in fact means that the actual RMS power is about half of this ie 40w per channel. This is plenty of power for the busking sessions that I use it for. I have the whole lot mounted on a small garden trolley and can just push it around.

Subject: RE: Tech: 12v sterio amp
From: harpmaker
Date: 20 Feb 03 - 06:22 PM

Thanks to all on this thread. Plenty to think about here. George it looks like I will have to look at car amps again, and Dave has the answer to inputs with a small mixer. This is looking good now. Now, small mixer?---- Tandy used to do a 4ch, but no longer supply the UK, What do you use dave? John J, Great idea I will look into-thanks (And to all)(looks like you where right all along open mike!)