Pioneer VSX-LX505 AVR Review

[dlaloum]

How far away are your speakers? You may not be stressing out the AVR if < 10 ft and/or don't listen at high volume!

If the AVR is getting stressed due to low impedances/high phase angles, it manifests at low power levels (ie: circa 1W @ 8ohm / 4W@2ohm ) - and it is not immediately obvious, as it is perceived as a smearing of the imaging and reduced clarity in vocals/dialogue.... I believe this indicates substantially increased distortion, rising into the audible range.

But it is important to note that in power/SPL level terms, there can be no stress involved, and the problem will still manifest. (from my experience with the DRX3.4/LX305/NR7100)

 

[MbphotoX]

If the AVR is getting stressed due to low impedances/high phase angles, it manifests at low power levels (ie: circa 1W @ 8ohm / 4W@2ohm ) - and it is not immediately obvious, as it is perceived as a smearing of the imaging and reduced clarity in vocals/dialogue.... I believe this indicates substantially increased distortion, rising into the audible range.

But it is important to note that in power/SPL level terms, there can be no stress involved, and the problem will still manifest. (from my experience with the DRX3.4/LX305/NR7100)

this would be a measurable effect. Do you have measurements supporting this claim?

 

[dlaloum]

this would be a measurable effect. Do you have measurements supporting this claim?

Nope, I have my listenign at home, and my comparisons - the difference between the (3.4) AVR and the amps was obvious - those same amps vs much more capable avrs' and vs other amps, were not audibly different from each other.

Like most people, I do not keep high tech instrumentation in my home.

 

[MbphotoX]

Nope, I have my listenign at home, and my comparisons - the difference between the (3.4) AVR and the amps was obvious - those same amps vs much more capable avrs' and vs other amps, were not audibly different from each other.

Like most people, I do not keep high tech instrumentation in my home.

Free Software (REW) and a microphone (can be the one included with the AVR, since you can find calibration curves for those, too) shouldn't be too much to ask, should it?

I have a high end stereo amplifier and can certainly NOT hear any such differences compared to the Pioneer..

 

[dlaloum]

Free Software (REW) and a microphone (can be the one included with the AVR, since you can find calibration curves for those, too) shouldn't be too much to ask, should it?

I have a high end stereo amplifier and can certainly NOT hear any such differences compared to the Pioneer..

But then you are (usually) measing speaker & mic distortion, not amp distortion, as speakers typically have circa 1% THD (very good ones get as low as 0.5%) where an amp under normal operating conditions (within its performance envelope) should be below 0.05% - ie: less than a tenth.... A misbehaving amp might creep up to 0.5% or 1 % - but that would still be difficult to distinguish from speaker distortion.

 

[MbphotoX]

But then you are (usually) measing speaker & mic distortion, not amp distortion, as speakers typically have circa 1% THD (very good ones get as low as 0.5%) where an amp under normal operating conditions (within its performance envelope) should be below 0.05% - ie: less than a tenth.... A misbehaving amp might creep up to 0.5% or 1 % - but that would still be difficult to distinguish from speaker distortion.

so, you're saying... that you cannot measure distortion from the amp bc it would be too low to even measure, since the speaker distortion masks it?!
but you can HEAR it "clearly"?! oh my...


If you're listening to the entire system, and can "clearly" hear differences, then those differences must show up on measurements from said system.. since that's what arrives at your ears.


Here are my measurements, comparing my old Pioneer SC-LX57 (above) to my Destiny Audio EL34 tube amp (below), both showing the left speaker.. dunno why the AV-R was so wavy while the tubes played more linearly in the upper bass/lower mids:

as you can see, the differences in distortion are clearly visible. (the sound was very audibly different, too, as you can imagine)


I have yet to run Dirac Live with the LX-505 in the 5.1 configuration, but when I get around to doing that, I'll get some REW measurements done, too. Might even compare to the Yamaha stereo amp while at it.

 

[Doodski]

@MbphotoX. Try this short video showing the various levels of distortion and what can and cannot be heard.

 

[Heyu]

I'm curious. Is the poor vote on the poll here based on user experience with the lx505 or only based on only going by what the reviewer had to say?

 

[Doodski]

I'm curious. Is the poor vote on the poll here based on user experience with the lx505 or only based on only going by what the reviewer had to say?

It was rated poorly because of this.>

QUOTE, "
As we see, it pulls back around the same time. This time the AVR was running pretty cool indicating this limiting is time based, no environment. You only have your maximum power for 35 seconds after which, power is limited until you power cycle the unit!

During my DAC testing, I went past the 35 seconds with volume cranked up causing the amplifier to run in power limiting. This explains why DAC performance was not dragged down with higher output voltages.

Because of this power limiting, I could not run my max and peak power ratings as that test forces the amplifier into clipping back and forth which obviously does not work. But here is the standard sweep:"

 

[Power Pop 23]

I'm curious. Is the poor vote on the poll here based on user experience with the lx505 or only based on only going by what the reviewer had to say?

I am not aware of the 'Poor' vote being broken out in any way. I suspect most of the 'Poor' votes are because of how the Pioneer Elite VSX-LX505 measured for output power.

 

[fadetoblackbs]

Adding an external amp hooking it up on the preouts (L/R front) would compensate this „problem“ or will this limitation still apply?

 

[Doodski]

Adding an external amp hooking it up on the preouts (L/R front) would compensate this „problem“ or will this limitation still apply?

That depends on how the unit senses the 35 second time-out when the unit is cranked up in output power. If it is voltage sensing then unless the amp section for the mains can be disabled the unit will still go into reduced power output mode.

 

[popej]

That depends on how the unit senses the 35 second time-out when the unit is cranked up in output power.

Most probably it is current from power supply.

LX505 specification is following:
2*120W/8Ohm (0.08% THD, 20 Hz - 20,000 Hz)
1*260W/6Ohm (10% THD, 1KHz)
850W power consumption.

Exceed any above and amplifier can go into protected mode. Amir has measured 2*144W, which already is more than promised. And you can't reach 2*140W with music, you will get clipping at much lower level.

 

[MbphotoX]

As was previously established:
The test was conducted outside of official specifications and not in a realistic manner.
Every other institution that tested the Pioneer (and identical Onkyos) has not found any such limitations or issues.

Amir never repeated the test and it seems that nobody has the means to replicate the test and check if it was indeed done incorrectly.

(Because nobody, ever, has reported any issues with this amplifier. People have noticed the amp switching to the low-energy mode to reduce power consumption when the load is to SMALL! but never the opposite.. because it's simply unrealistic to draw 800+ Watts continuously from an amplifier... )

 

[kyuu]

The issue Amir found appears to be based on a timer or on a thermal threshold that the AVR reaches at a regular time threshold. Either way, it has nothing whatsoever to do with stressing the receiver or not.

Has anyone confirmed that other units are not doing this? Otherwise I would have no reason to expect they behave differently than the one Amir tested.

The fact that people without measurement gear haven't reported issues doesn't mean much one way or the other. The unit doesn't report when it's power limiting.

 

[dlaloum]

The issue Amir found appears to be based on a timer or on a thermal threshold that the AVR reaches at a regular time threshold. Either way, it has nothing whatsoever to do with stressing the receiver or not.

Has anyone confirmed that other units are not doing this? Otherwise I would have no reason to expect they behave differently than the one Amir tested.

The fact that people without measurement gear haven't reported issues doesn't mean much one way or the other. The unit doesn't report when it's power limiting.

As I said before, it DOES report it... but ONLY on the web interface status screen - which is also where you get temperature, and fan speed info.

So it is an awkward and inconvenient user interface rather than a feature/function gap.

It would be of interest to know what the fan speed and measured temperature were, when the trigger Amir reported was hit.... That might shed some light on whether something thermal is involved or not.

 

[Heyu]

Somewhere I read about someone having this receiver making a noise with mv around 40db going into power saving mode but I watch movies with this unit at -15 and I've yet to notice such sound.
However reading all this makes me rethink my purchase. I have two weeks for a return.

 

[EWL5]

Somewhere I read about someone having this receiver making a noise with mv around 40db going into power saving mode but I watch movies with this unit at -15 and I've yet to notice such sound.
However reading all this makes me rethink my purchase. I have two weeks for a return.

Have you tried using the Dirac license? Costs nothing for you to evaluate even if you end up returning the unit!

 

[Heyu]

Have you tried using the Dirac license? Costs nothing for you to evaluate even if you end up returning the unit!

I have tried the dirac license. I was referring to the power loss that was evaluated here by Amir how after awhile it goes into like power saving mode or timer and makes like a click sound that someone mentioned happening to their unit. Mine has not done so but I am questioning if I should return it since this is an issue although mine sounds great.

 

[EWL5]

I have tried the dirac license. I was referring to the power loss that was evaluated here by Amir how after awhile it goes into like power saving mode or timer and makes like a click sound that someone mentioned happening to their unit. Mine has not done so but I am questioning if I should return it since this is an issue although mine sounds great.

If there's no issue, I don't see why you would return it. Just make sure to test it out at your normal listening volume and not to "baby" it or it might hide limitations!

Amir's observation was for low impedance speakers and you may not own any!