Pioneer VSX-LX305 power usage issues

[Drunkinho]

I have Pioneer VSX-LX305 and I've noticed something similar to the Amir results but during normal level of usage tests.
Watching movies or listening to the music over Spotify connect at -40dB.
After 25 minutes when watching movies there is that sound exactly as it is when you are powering on the AVR. I don't know how to call it.
I was wondering what it is and if it had any impact on the AVR performance. No sound dynamic, volume changes "visible" after this "click".
I've bought power monitoring socket and connected AVR through it. Guess what is happening after those 25 minutes and that "click" sound? I've marked time of this "click" sound with red circles on the screenshot from the power monitoring app.
Power usage goes down 50%. And that 25 minutes mark is consistant. Every time. No matter if when watching movies in 5.1 or listening music in 2.1 configuration.
The same sound and power usage behaviour is visible when changing impendance to option:
4ohms - When any of the connected speakers have 4 Ω or more to less than 6 Ω impedance.
Power usage is basically half of comparing to the power usage when impedance is set to:
6 ohms or above - When the connected speakers all have 6 Ω or more impedance - I have this impedance set since beginning.
I don't know what to think of it. There is no eco mode in this AVR also. No indication that it could be related to overheating (fan is always off no matter what) - not likely I've setup a desktop fan on full power directly on the AVR to exclude any overheating issues. Same result. 25 minutes. Click. Power usage goes down 50%.

Anyone has LX305 and can confirm similar issue?

 

[Drunkinho]

UPDATE:

Ok. Looks like that power usage changes are related to the volume/power needed. I've increased volume to -15dB and power usage spiked back to the previous levels.
Around 80W.
Lower volume - lower power usage.
Higher volume - higher power usage.
I guess amp does not need full power and it is lowering power usage after some time when I use lower volume.

 

[peng]

UPDATE:

Ok. Looks like that power usage changes are related to the volume/power needed. I've increased volume to -15dB and power usage spiked back to the previous levels.
Around 80W.
Lower volume - lower power usage.
Higher volume - higher power usage.
I guess amp does not need full power and it is lowering power usage after some time when I use lower volume.

The AVR will use a certain amount of "power" for the video section, and overheads such as transformer magnetizing current, amplifier bias currents etc., plus the power required by the connected speakers. The latter is obviously variable depending on the demand that varies with the contents being play, and the volume control setting.

Your "I guess amp does not need full power and it is lowering power usage after some time when I use lower volume." does not sound quite right. The amp is there to supply the power demanded by the speakers. At lower volume, it would have a lower maximum available output limit than if it is at a higher volume setting, but that is not the same as "lowering power usage....." as the "usage" will still vary according the contents, and if the demand is within the amp's output limit at the given volume setting, then the amp is not responsible for lowering power usage, not until the load demand exceeds the limit set by the volume, and the contents.

 

[EWL5]

The AVR will use a certain amount of "power" for the video section, and overheads such as transformer magnetizing current, amplifier bias currents etc., plus the power required by the connected speakers. The latter is obviously variable depending on the demand that varies with the contents being play, and the volume control setting.

Your "I guess amp does not need full power and it is lowering power usage after some time when I use lower volume." does not sound quite right. The amp is there to supply the power demanded by the speakers. At lower volume, it would have a lower maximum available output limit than if it is at a higher volume setting, but that is not the same as "lowering power usage....." as the "usage" will still vary according the contents, and if the demand is within the amp's output limit at the given volume setting, then the amp is not responsible for lowering power usage, not until the load demand exceeds the limit set by the volume, and the contents.

Could this be how Onkyo/Pioneer is able to advertise "certified for 4 ohm" service?

 

[peng]

Could this be how Onkyo/Pioneer is able to advertise "certified for 4 ohm" service?

I don't know, but it already has a 4 ohm setting, so I think what drunkinho described is more likely some sort of protection mode, and/or a variation of eco mode. Someone should just ask Pioneer support about it.

 

[Drunkinho]

More like hidden/automatically engaged eco mode.
No Eco Mode (like it is in Denon) in any of the menus. No info in the manual.

 

[ban25]

More like hidden/automatically engaged eco mode.
No Eco Mode (like it is in Denon) in any of the menus. No info in the manual.

Or it's just turning off the video section after a timeout, since that is the primary power consumer in the AVR.

 

[Drunkinho]

Which video section? And if yes why power consumption is going back up by 50% when increasing volume to high levels.
Does not make sense.

 

[peng]

Which video section? And if yes why power consumption is going back up by 50% when increasing volume to high levels.
Does not make sense.

I don't trust those power consumption displays that show % such as 50%, power consumption, that is almost a misnomer as by definition is it the rate of energy consumption and it should be continuously varying depending on the contents. Try playing a symphony such as Beethoven's no. 9 and if how the display fluctuates, if it still looks like the graph you posted, then whatever you are using is something that just give a rough idea. I am not saying it is not indicating something, it certainly is, but I would say likely not enough information to figure what the AVR is actually doing.

Best bet would be to ask customer support and insist that if they don't have an answer, try to get an answer for you from their level two support, or their engineering department. That's if you really want to know, many users would probably not bother and just enjoy their unit listing to music lol... If you do get a credible response from customer support, I would appreciate you share the info.

 

[popej]

Looking at service manual for older models, we can find a switch for power amps supply. High supply voltage is +-64V, low is +-26V. This low voltage is consistent with Amir's measurement in protected mode, where output power drops to about 20W/8Ohm and 35W/4Ohm. It should be the same for low volume mode.

 

[EWL5]

Looking at service manual for older models, we can find a switch for power amps supply. High supply voltage is +-64V, low is +-26V. This low voltage is consistent with Amir's measurement in protected mode, where output power drops to about 20W/8Ohm and 35W/4Ohm. It should be the same for low volume mode.

The odd thing was that he showed a screenshot that he wasn't in "protection mode". That's why I never brought it up after that!

 

[popej]

It is not protected mode, but it use the same power supply configuration.

 

[MbphotoX]

I don't trust those power consumption displays that show % such as 50%, power consumption, that is almost a misnomer as by definition is it the rate of energy consumption and it should be continuously varying depending on the contents. Try playing a symphony such as Beethoven's no. 9 and if how the display fluctuates, if it still looks like the graph you posted, then whatever you are using is something that just give a rough idea. I am not saying it is not indicating something, it certainly is, but I would say likely not enough information to figure what the AVR is actually doing.

Best bet would be to ask customer support and insist that if they don't have an answer, try to get an answer for you from their level two support, or their engineering department. That's if you really want to know, many users would probably not bother and just enjoy their unit listing to music lol... If you do get a credible response from customer support, I would appreciate you share the info.

his measurements are not % but rather actual wattage drawn by the device.
he said the reading jumped up by 50%, which isn't quite accurate, since it dropped from roughly 70W down to 39W and then, after a power cycle, went back up to 75W, only to slowly decrease again to 62W after 25 minutes, when the relay switches once more and pushes it down to 39 or so Watts.

You would expect the power drawn to fluctuate during high dynamic music being played.
That will certainly occur if OP plays the music at an "adequate" level, at around -20 or even -10dB on the volume setting. (averaging 80 dB SPL when streaming music or watching a movie)

At -40 dB setting the average volume of a movie (Dolby, after calibrating with Dirac) will be somewhere around maybe 40 dB (accounted for room gain)
As you can expect, the speakers are not drawing any Watts in the single digits... we're talking milli Watts here.

What OP measured was the immense amount of power drawn from the Receiver not doing anything really.


Sounds smart that the relay switches the voltage to the amplifiers if it detects that barely any power is required.

I don't like that this is automated and that there's no sign of it being activated anywhere on the receiver.

 

[peng]

his measurements are not % but rather actual wattage drawn by the device.
he said the reading jumped up by 50%, which isn't quite accurate, since it dropped from roughly 70W down to 39W and then, after a power cycle, went back up to 75W, only to slowly decrease again to 62W after 25 minutes, when the relay switches once more and pushes it down to 39 or so Watts.

You would expect the power drawn to fluctuate during high dynamic music being played.
That will certainly occur if OP plays the music at an "adequate" level, at around -20 or even -10dB on the volume setting. (averaging 80 dB SPL when streaming music or watching a movie)

At -40 dB setting the average volume of a movie (Dolby, after calibrating with Dirac) will be somewhere around maybe 40 dB (accounted for room gain)
As you can expect, the speakers are not drawing any Watts in the single digits... we're talking milli Watts here.

What OP measured was the immense amount of power drawn from the Receiver not doing anything really.


Sounds smart that the relay switches the voltage to the amplifiers if it detects that barely any power is required.

I don't like that this is automated and that there's no sign of it being activated anywhere on the receiver.

Right, W it is, I don't know why I said %, but what I said still apply, that steps graph does not make much sense, may be fine for rough ideas but not more than that...

 

[Heyu]

I just got the lx505 and while watching movies around -15 -20 and I've had no issues with the avr making a sound like when it powers on.

 

[Tucker26]

I believe at least some (all?) of the current Pioneer AVR's have class G or H power amplifiers which have 2 sets of rails, a low voltage one when playing at moderate output and below, and high voltage for high output demand Designed properly, these are an elegant design option for reducing cost, heat output, and product weight, without any significant disadvantages that I know about. Among the benefits are allowing, effectively, class A operation at low outputs and class B at high outputs, with automatic switching between depending on output demand. More and more class G and H power amplifiers have appeared on the market in the last few years, including both Professional and Consumer amplifiers, including some that are premium products where the cost is less of a consideration. However, the "designed properly" qualification is the operative word here, and any design that latches up in a low output mode requiring a restart in order to operate normally is clearly not "designed properly" for music applications, especially (IMHO) when there is no indication of the operating mode. Sort of like many cars with automatic transmissions without any indication of the operating gear- automatically in the wrong gear, that is.

 

[MbphotoX]

I believe at least some (all?) of the current Pioneer AVR's have class G or H power amplifiers which have 2 sets of rails, a low voltage one when playing at moderate output and below, and high voltage for high output demand Designed properly, these are an elegant design option for reducing cost, heat output, and product weight, without any significant disadvantages that I know about. Among the benefits are allowing, effectively, class A operation at low outputs and class B at high outputs, with automatic switching between depending on output demand. More and more class G and H power amplifiers have appeared on the market in the last few years, including both Professional and Consumer amplifiers, including some that are premium products where the cost is less of a consideration. However, the "designed properly" qualification is the operative word here, and any design that latches up in a low output mode requiring a restart in order to operate normally is clearly not "designed properly" for music applications, especially (IMHO) when there is no indication of the operating mode. Sort of like many cars with automatic transmissions without any indication of the operating gear- automatically in the wrong gear, that is.

It doesn't latch into the low output mode.. as far as we know, when you crank up the volume, it will switch back to high output mode.

(I really need one of those fancy measurement thingies that OP has..)

 

[peng]

It doesn't latch into the low output mode.. as far as we know, when you crank up the volume, it will switch back to high output mode.

(I really need one of those fancy measurement thingies that OP has..)

Agreed, that's the way it should have been designed, "latched" would not make sense unless it was triggered by a fault event such as thermal overload and that's probably what was experienced during the test. Still, the OP has not posted more info about how he obtained that chart, such as, was it from some sort of the so called kill-a-watt meter, or a better meter that actually measure power consumption in terms of average, peak, etc.., and the load condition, was it just idling with different volume settings or actally playing music? Sorry if answer to my question about the measurements have been given by the op, I have only quickly browsed through the post once from beginning to end, so might have missed something.

 

[ban25]

Agreed, that's the way it should have been designed, "latched" would not make sense unless it was triggered by a fault event such as thermal overload and that's probably what was experienced during the test. Still, the OP has not posted more info about how he obtained that chart, such as, was it from some sort of the so called kill-a-watt meter, or a better meter that actually measure power consumption in terms of average, peak, etc.., and the load condition, was it just idling with different volume settings or actally playing music? Sorry if answer to my question about the measurements have been given by the op, I have only quickly browsed through the post once from beginning to end, so might have missed something.

On my DRX-8.4, the relay activates at -22 dB in the relative scale (59 in absolute scale) to switch rails.

 

[popej]

Isn't volume scale adjusted after calibration? On my LX305 switching depends on signal level too.