Audio Precision Participation at our SOTU Trade Show Event to Discuss Amplifier Measurement

[admin]

As many of you are aware, I am not champion of the classic All Channels Driven (ACD) test popularized by many of the major audio magazines as an accurate way of gauging amplifier performance. Thus I figured what better time than our 2008 SOTU Trade Show event this October 23rd and 24th at the Disney Dolphin Resort in Orlando Florida to invite Audio Precision – the world’s leading manufacturer of high end audio test equipment to talk about the measurements behind more meaningful multi channel amplifier standards. Join us at our event for great demos, food, education and fun!


Discuss " Audio Precision Participation at our SOTU Trade Show Event to Discuss Amplifier Measurement" here. Read the article.

[mtrycrafts]

As many of you are aware, I am not champion of the classic All Channels Driven (ACD) test popularized by many of the major audio magazines as an accurate way of gauging amplifier performance. Thus I figured what better time than our 2008 SOTU Trade Show event this October 23rd and 24th at the Disney Dolphin Resort in Orlando Florida to invite Audio Precision – the world’s leading manufacturer of high end audio test equipment to talk about the measurements behind more meaningful multi channel amplifier standards. Join us at our event for great demos, food, education and fun!
Discuss " Audio Precision Participation at our SOTU Trade Show Event to Discuss Amplifier Measurement" here. Read the article.

That should be very interesting
I wonder though if the realities of the recorded material be accounted for. For example, are there any recorded material out there, not test tones, that would ever require all channels driven to max power at the same instant, or time interval where it would tax the power supply to a max demand?
Perhaps a duty cycle that would apply to a certain percentage of the recordings, if that is even possible to establish?
Such test may be more relevant than a full power to all channels?
I would also wonder if full frequency really matters that much since the signals are so varied and dynamic at all times.
Maybe he has a better fell for this concern?

[jliedeka]

That was an interesting read. I've noticed that the claimed WPC of my receiver adds up to more than the rated power of the transformer. I've also wondered why some amplifiers claim more power than you could get out of 15 amps. I wasn't even aware of the 12 amp limit and hadn't considered inefficiencies in the amplifier.

Jim

[gene]

That was an interesting read. I've noticed that the claimed WPC of my receiver adds up to more than the rated power of the transformer. I've also wondered why some amplifiers claim more power than you could get out of 15 amps. I wasn't even aware of the 12 amp limit and hadn't considered inefficiencies in the amplifier.

Hence one of the many reasons you should attend our event this October at Disney

[mtrycrafts]

That was an interesting read. I've noticed that the claimed WPC of my receiver adds up to more than the rated power of the transformer. I've also wondered why some amplifiers claim more power than you could get out of 15 amps. I wasn't even aware of the 12 amp limit and hadn't considered inefficiencies in the amplifier.

Jim

Is it? Or just adding up each channel's power is not what it is rated for And, it is not rated like that for a good enough reason. Never get full power demand from all channels at the same instant.

[jliedeka]

My Marantz SR8002, according to the specifications on page 82 of the manual, is capable of 125 WPC at 8 ohms including Front L&R, Center, Surround L&R and Rear Surround L&R. At 6 ohms, they claim 160 WPC. Assuming 120V that means 7.3 Amps at 8 ohms and 9.3 Amps at 6 ohms. Yet, the power consumption is rated at 6.7 Amps.

I'll admit I'm not a math genius but I think 6.7 is less than both 7.3 and 9.3. If you figure 115 or 110 volts, the number of amps would be higher.

At least they rate the WPC 20-20kHz with THD 0.08% for both figures.

Jim

[3db]

My Marantz SR8002, according to the specifications on page 82 of the manual, is capable of 125 WPC at 8 ohms including Front L&R, Center, Surround L&R and Rear Surround L&R. At 6 ohms, they claim 160 WPC. Assuming 120V that means 7.3 Amps at 8 ohms and 9.3 Amps at 6 ohms. Yet, the power consumption is rated at 6.7 Amps.

I'll admit I'm not a math genius but I think 6.7 is less than both 7.3 and 9.3. If you figure 115 or 110 volts, the number of amps would be higher.

At least they rate the WPC 20-20kHz with THD 0.08% for both figures.

Jim

You forgot to multiply in the cosine of the power factor angle. In AC, in a purely reactive circuit, voltage leads current by 90 degress in a capacitive circuit and lags current by 90 degrees in an inductive circuit. Throw the two together and resistance and your power factor angle reduces less than 90 degrees. In a purely resistive circuit, current and voltage are in phase.

[mtrycrafts]

My Marantz SR8002, according to the specifications on page 82 of the manual, is capable of 125 WPC at 8 ohms including Front L&R, Center, Surround L&R and Rear Surround L&R. At 6 ohms, they claim 160 WPC. Assuming 120V that means 7.3 Amps at 8 ohms and 9.3 Amps at 6 ohms. Yet, the power consumption is rated at 6.7 Amps.

I'll admit I'm not a math genius but I think 6.7 is less than both 7.3 and 9.3. If you figure 115 or 110 volts, the number of amps would be higher.

At least they rate the WPC 20-20kHz with THD 0.08% for both figures.

Jim

Yes, it is interesting
But, another but,, the way you are figuring is not the way it is rated.
Yes, each of those channels is capable of producing 120 watts continuous power BUT, not at the same instant since that event on recorded software has yet to be met. The front two channels are so rated in the calculations and the rest are rated at 1/8 power, plus the amp efficiency.

Go to your circuit panel in the house and add up all the breakers value. I bet it will exceed the main breaker value Why? Because no residential house will use all that full power at the same instant on each breaker

[3db]

Yes, it is interesting
But, another but,, the way you are figuring is not the way it is rated.
Yes, each of those channels is capable of producing 120 watts continuous power BUT, not at the same instant since that event on recorded software has yet to be met. The front two channels are so rated in the calculations and the rest are rated at 1/8 power, plus the amp efficiency.

Go to your circuit panel in the house and add up all the breakers value. I bet it will exceed the main breaker value Why? Because no residential house will use all that full power at the same instant on each breaker

Unless you're a Griswald at Christmas