Help with fixing speaker system...

[NuAngel]

I have a speaker set, that says it needs 13.5V to run (13.5V DC IN, and the big power brick thing says 13.5) - but my power brick is dead. I just hooked up a 12V power source, and the LED came on. So at least I know it's not my sub woofer (where all the speakers / volume control plugs in).

Question is: can I run at 12v, just not as loud? Or will this blow something up, cause a fire, etc...? Or will it just cause damage over time? Or will it work FINE, with no major hazards, just not get as loud?

Other numbers to consider:

ORIGINAL HARDWARE: Input 120 VAC 60Hz 50W Output 13.5VDC 2.5A

POSSIBLE REPLACEMENT Input 120V AC 60Hz 23W Output 12VDC 1000mA

If it works, just not as loud, I'm set... I really don't want to spend more money on another powersupply.

Thanks!

Nu

[Abe]

Depends on the electronics in the sub. Some electronics will not run when underpowered.

[NuAngel]

-I guess my question is, if it DOES run, will I be hurting something? Or is that more of a case-by-case basis, too?

Nu

[Reed]

It may well run on the 12 Volts OK, but I would be concerned that the current (Amps or mA) rating of the 12V PS is less than half of the original. This could lead to overheating of the PS, etc. Without knowing what the speakers minimum Amp draw is, there is some risk.

BTW, 13.5 Volts DC is same as automotive DC voltage (nominally 12 Volt). The set is probably also sold in an automotive version. What does a replacement "brick" from speaker vendor cost ?? A 13.8VDC 3 Amp PS from RS is $42US. Model 22-507 at

[Tony Hwang]

Hi, No. Not at all.

[richardcool]

You need to look at the acceptable voltage range for your speaker set. They usually specify a "±".

12V may be acceptable.

Typically I've seen 13+ VDC called out because of the use of a linear regulator. Typically at least a 0.7V margine is required to regulate to

12VDC (so input of greater than 12.7VDC).

...but again, check out the input DC requirement.

Also note the power limitation on your PS:

ORIGINAL HARDWARE: Input 120 VAC 60Hz 50W Output 13.5VDC 2.5A

-> 50W. .. actually more like 35W

POSSIBLE REPLACEMENT Input 120V AC 60Hz 23W Output 12VDC 1000mA

-> 23W ... more like 15 W to your system.

[m Ransley]

Your possible replacement supply does not have the required power for proper operation, neither volts or what it realy needs amps-watts it will probably work at 1/2 volume or less and may damage the supply and the amp

[Mark Lloyd]

Try measuring the output of the power supply. An unregulated 12v supply could be putting out 20v of more. If that 13.5 volt supply was unregulated, your speakers must be able to handle such things.

However, the significantly lower current capacity may keep the speakers from working. It is unlikely that trying it will cause damage, but disconnect it if you hear strange sounds from the speakers.

[Bob M.]

Your 'possible replacement' doesn't provide as much power. The voltage is not an issue (if you measured the original one when it was working, it was probably between 10 - 18 volts, "wall wart" transformers are usually way off), but the amperage probably will be. The original one put out 2.5 amps, the replacement puts out 1 amp (1000 mA). At low volume it may work fine, but when you crank it up, the replacement power supply will not be able to provide the amount of juice needed.

[mm]

As others said, the big problem is that the replacement only puts out

1 amp, which is why it only has 23 watts instead of 50.

Measure while it is in use, I think you mean. All wall warts and most other cheap PS's will be higher when not connected to the amp and when the amp is not turned on.

Also someone mentioned PS failure from overheating. I think a) if the power supply fails, you probably won't have lost much, since this sounds like a spare, but for the first several long sessions you should put the PS where it can't start a fire. (at the end of an extension cord, so you can put it where you want it.) Better yet, if you touch the PS and it's no hotter than others that look like it (we're talking about a black cube that plugs into the wall, right) it's not likely to be overheating.

I don't see why the amp would fail from low capacity in the power supply, especially if it sounds ok.