I have so many high-qaulity home amps lying around--monitor audio asw sub-amp, sunfire sub-amp... and would like to chat about the possibility of converting them to 12 volts for car use. Would this be as simple as replacing the transformer on the board? Or does this just a stupid idea?
Unfortunately, it's not as simple as changing transformers.
While the amplifier section is essentially the same in a car amp, the power supply has to convert the battery's DC to AC before it can be stepped up by transformer to a useful level.
This is done by chopping the DC at a regular frequency into square wave AC. At that point, it goes through a transformer. The 'chopping' frequency (actually called switching frequency) is ~1000x higher than the 50/60HZ used in household voltage, which allows the use of much smaller transformers.
Power supply regulation, if it exists, is typically done by the switching controller.
Here's the most relevant thread in this forum to the process:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=31614
While the amplifier section is essentially the same in a car amp, the power supply has to convert the battery's DC to AC before it can be stepped up by transformer to a useful level.
This is done by chopping the DC at a regular frequency into square wave AC. At that point, it goes through a transformer. The 'chopping' frequency (actually called switching frequency) is ~1000x higher than the 50/60HZ used in household voltage, which allows the use of much smaller transformers.
Power supply regulation, if it exists, is typically done by the switching controller.
Here's the most relevant thread in this forum to the process:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=31614
A simple way would be to hook up a high wattage inverter. Just match the inverters output wattage to what your amplifiers draw. My project is the opposite. Have a.bunch of car amplifiers and running a alternator/battery with an electric motor for my home theater system.
surely car amps would also be built a bit more rugged than home amp's 'cos of all the vibrations and bumps.
dunno if a home amp will last long in a car environment.
dunno if a home amp will last long in a car environment.
mramplifier40 said:A simple way would be to hook up a high wattage inverter. Just match the inverters output wattage to what your amplifiers draw.
Way, way back in time, long before car amplifier companies existed, in a galaxy far, far away I had a spare Kenwood KA-6004 in my very first vehicle. It was powered off of a now antique square wave type inverter. 400 watter as i recall...
I had SQ in 1975 in my Chevy van that could not and would not be matched for some years to come. It was expensive, ungainly both in weight and size. BUT it connected to a spare Teac reel to reel and a remote controlled AM / FM home receiver to form my very first car stereo project.
I had three way book shelf speakers, BIC Venturi as I recall with 10 inch woofers back when Kraco 6x9's with cheesy push pull transformer coupled amps bolted onto the backs of them ruled the universe🙂 🙂 🙂
Yes it worked, and I did not blow up anything except a few alternators trying to power it. I like to think I was ahead of most of you folks who now live in car audio. Yes I got the eye from many around me as I was but 18 and crazy in many peoples eyes at that time.. But just look at the industry thinking like this has spawned....Ahhh if I had only had financial backers........
surely car amps would also be built a bit more rugged than home amp's 'cos of all the vibrations and bumps. dunno if a home amp will last long in a car environment.
Back in the 70's home amps were battleships 35 pounds for a 80 watt amp. Newer stuff today is pretty flimsy inside, and like he said you might be breaking things on a regular basis. But this is just due to the design concepts that are acceptable for home use nowadays. Long ago built like a tank was the rule for any audio gear.
Nowadays you should look for modified sine wave inverters. They are cheap and fairly prevalent everywhere. But you should by now be able to get a fairly clean AC power source for your project idea, and like was said above please match your inverter wattage rating to your equipment draw, then build up your 12 volt charging system to match the expected power loading you have in mind... It can work, if you have the time and money..lots and lots of money.....
Car amps and head units are now so cheap I would never even consider such a thing unless it was a mobile studio situation.. and no one wants to think about how much that costs even nowadays...
I assembled what I did back then because there was no car audio industry in 1975 that suited my tastes in audio, so I rolled my own so to speak out of spare HiFi gear I had laying about unused. No one in there right mind needs to do this in our current times of DVD surround sound and Navigation with kilo-watt based class D amplifiers for the auto industry....Just way to expensive, and the gas mileage loss alone due to excessive weight added to the vehicle...well it just all adds up the wrong way nowadays...Hope you see my point about this I have truly already done this once out of necessity, but there is no need nowadays. It's all being built for you in China

Turn ur car amp into home amp
Go to goodwill or somewhere you can find miscellaneous laptop chargers and find one that is 120 in + 12 volt out run it to your amp just like you would in a car and you wouldn't have to plug in an electric motor to run a alternator to charge a battery to run it off of that and in the house and all that all it is is a laptop 12 volt converted charger I've done it plenty of times plenty of times at jobs in the shop that we didn't have a radio in
Go to goodwill or somewhere you can find miscellaneous laptop chargers and find one that is 120 in + 12 volt out run it to your amp just like you would in a car and you wouldn't have to plug in an electric motor to run a alternator to charge a battery to run it off of that and in the house and all that all it is is a laptop 12 volt converted charger I've done it plenty of times plenty of times at jobs in the shop that we didn't have a radio in
9 years later...........................................
I must say, I wonder how the OP made out with this! I'm guessing he decided not to bother with it in the end.
I also wonder if "1moreamp" is still around, I vaguely remember something about him having health issues a few years back, and have not seen him post in quite a while now.
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