240V power amps

Their are a couple of reasons for 240V operation (assuming you are in a country that offers both 240 and 120V)

The current draw is 1/2 of that at 120V. Also there will not be any current on the neutral line, so no loss there for other item running at 120V.

So you can get away with a smaller distro cable.

It also helps to balance the load on the buildings transformer.

The best thing is to have amps that will run off of either-without having to flip switches or move jumpers. THAT can get you in trouble.

In some cases you can get additional power for a longer period to time on 240V, because 120V cannot "refill" the power supply enough.

 
I am not sure I understand the "refill" issue Ivan alludes to (mains voltage sag?), but all else equal running the same amps at 240V will result in lower IxR wire losses in the mains wiring due to lower current draw. In some cases, this higher mains voltage could result more actual power available for the speakers.

That said I do not expect huge audible differences, but free power is never a bad thing.

JR
 
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John Roberts said:
I am not sure I understand the "refill" issue Ivan alludes to (mains voltage sag?), but all else equal running the same amps at 240V will result in lower IxR wire losses in the mains wiring due to lower current draw. In some cases, this higher mains voltage could result more actual power available for the speakers.

That said I do not expect huge audible differences, but free power is never a bad thing.

JR
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I believe Ivan's point is that if you expend all of the power from a half cycle during that half cycle, you must wait until the next half cycle to "refill" your power supply. Unfortunately, Ivan has made a slight error since, while 120v and 240v are both multiples of 60Hz, they are not the mains frequency.

Either that or he intends that 240v can carry more wattage due to the increased voltage and therefore, as you suggest, doesn't cause as much voltage drop when the supply needs to be refilled. I think the first one is more amusing, however.
 
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Ivan Beaver said:
Their are a couple of reasons for 240V operation (assuming you are in a country that offers both 240 and 120V)

The current draw is 1/2 of that at 120V. Also there will not be any current on the neutral line, so no loss there for other item running at 120V.

So you can get away with a smaller distro cable.

It also helps to balance the load on the buildings transformer.

The best thing is to have amps that will run off of either-without having to flip switches or move jumpers. THAT can get you in trouble.

In some cases you can get additional power for a longer period to time on 240V, because 120V cannot "refill" the power supply enough.
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So if I had a bunch of Crown Xti's and the right distro connectors I might squeak a little more power from them? Would have to get the right power cords for the amps and the right outlets on my distro but the amps sense the voltage and act accordingly??
Interesting...
 
Gene Hardage said:
So if I had a bunch of Crown Xti's and the right distro connectors I might squeak a little more power from them? Would have to get the right power cords for the amps and the right outlets on my distro but the amps sense the voltage and act accordingly??
Interesting...
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XTI or XTI2's? I don't believe the first generation have a sensing power supply. XTI2's do.
 
Steve Ferreira said:
XTI or XTI2's? I don't believe the first generation have a sensing power supply. XTI2's do.
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Correct, the XTI do not have universal power supplies.

The manual for the XTI2 shows "AC Live Voltage and Frequency Configurations Available: 100v, 120v, 220-240v 50/60Hz". Nothing about being universal or auto-selecting is mentioned, though. Who wants to hook up his XTI 6002 to 240v and lets us know?
 
XTi2 does not have it either. It can come in those configurations, but does not have the global power supply like the ITech series does.
 
Tim McCulloch said:
Correct, the XTI do not have universal power supplies.

The manual for the XTI2 shows "AC Live Voltage and Frequency Configurations Available: 100v, 120v, 220-240v 50/60Hz". Nothing about being universal or auto-selecting is mentioned, though. Who wants to hook up his XTI 6002 to 240v and lets us know?
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Just had a look at the manual and the pictures show the following:
XTI4002 over the power plug says 100-240V 50/60Hz
XTI6002 120/220-240V 50/60Hz

Might be a misprint but reading that would make it seem like the 4002 has voltage sensing.
 
Both XTi and XTi2 are indeed auto sensing, they are however not auto regulating. If you plug the amp into 120V it will run as a 120V amp. if you plug it into 240 it will run as a 240V amp. if you plug it into 120V and raise the voltage the amp will power down. power it back up and it will run at the higher voltage.
 
KEITH ERICKSON said:
Both XTi and XTi2 are indeed auto sensing, they are however not auto regulating. If you plug the amp into 120V it will run as a 120V amp. if you plug it into 240 it will run as a 240V amp. if you plug it into 120V and raise the voltage the amp will power down. power it back up and it will run at the higher voltage.
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Where did you see this information? I didn't see it in the manual at all when I went looking.
 
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