Help with fixing speaker system...
 

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 HARDWA
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

Help with fixing speaker system...
 

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

-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

Help with fixing speaker system...
 

wrote:
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 HARDWA
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

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 http://www.radioshack.com

Help with fixing speaker system...
 

Help with fixing speaker system...
 

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 HARDWA
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.

Help with fixing speaker system...
 

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

Help with fixing speaker system...
 

On 9 Jun 2006 21:57:57 -0700, wrote:

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 HARDWA
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

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.
--
Mark Lloyd
http://notstupid.laughingsquid.com

"Democracy is two wolves and a lamb voting on what
to have for lunch. Liberty is a well armed lamb
contesting the vote." - Benjamin Franklin

Help with fixing speaker system...
 

wrote in message
ups.com...


Other numbers to consider:

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

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

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.

Help with fixing speaker system...
 

On Sat, 10 Jun 2006 09:54:02 -0500, Mark Lloyd
wrote:

On 9 Jun 2006 21:57:57 -0700, wrote:

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 HARDWA
Input 120 VAC 60Hz 50W
Output 13.5VDC 2.5A

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

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.

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

Thanks!

Nu

Try measuring the output of the power supply.

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.

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.

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.