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lukeamdman

Luke's basic amplifier tests

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lukeamdman    153

I read that article many years ago, and in some cases, it can be applicable. Keep in mind that you are also driving essentially a dummy resistor load, and the results may be different driving a reactive load, where back EMF is reflected on the power supply.

 

I'm sure someone could find an application for this, but the more I think about it the less it seems worth the hassle.  Wouldn't it be easier to series the load and use the amp in bridged mode like you normally would, and skip the parallel inputs and reversing the polarity on one of the outputs?  

 

Even in the best case scenario of a 15% gain, we're talking about a fraction of a single dB of gain.  

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Ukko Kari    2

I'm sure someone could find an application for this, but the more I think about it the less it seems worth the hassle.  Wouldn't it be easier to series the load and use the amp in bridged mode like you normally would, and skip the parallel inputs and reversing the polarity on one of the outputs?  

 

Even in the best case scenario of a 15% gain, we're talking about a fraction of a single dB of gain.  

 

The real answer is it depends. I agree that it may only be a small fraction of a difference. It would be interesting to note the input power to the amplifier to see if the efficiency / breaker utilization changes any, which may be a bigger deal for large systems with racks and racks of amplifiers running off a generator, or in a venue where power is subject to droop. ( older wiring, smaller services )

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Ricci    637
On ‎3‎/‎25‎/‎2017 at 9:57 PM, lukeamdman said:

I was asked to test this over 2 months ago but I've been a huge slacker:

 

http://www.prosoundweb.com/topics/sound_reinforcement/fighting_for_power_a_way_for_amplifiers_to_increase_actual_power_delivered_/

 

The basic theory is that if an amp is driven in stereo and both channels are producing the exact same signal, both channels are also drawing current from the power supply at the exact same time/interval.  The author of the article claims that if you parallel the inputs but flip the polarity on the input of one of the channels, causing the sine waves from each channel to be exact opposites, the channels are now "taking turns" drawing current from the power supply.  

This is how Powersoft K series amps operate all of the time. Those guys are smart so you'd have to assume they did that for a reason. This likely only shows up as a measureable improvement when the power draw becomes large and starts to sag the AC line. More useful for pro sound apps where you might have many amps driven hard on one circuit and/or the circuit isn't great to begin with like a generator, etc.

Many years ago Ivan Beaver from Danley Sound showed me how to do this at a GTG. Flip polarity of one input channel in the amp and re-flip/correct at the speaker wiring to bring back in phase. Worked pretty good with a Crown CE4000.

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Ricci    637
59 minutes ago, manninen said:

238595829928168.jpg

Wonder if he will "loan" me one for testing? LOL.

What does he expect people to power with these? I guess it could be useful in an arena or very large concert hall. for that price I'd expect some dsp and networking options and maybe a free hat.

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