• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Pioneer VSX-LX505 AVR Review

Rate this AVR:

  • 1. Poor (headless panther)

    Votes: 163 66.0%
  • 2. Not terrible (postman panther)

    Votes: 45 18.2%
  • 3. Fine (happy panther)

    Votes: 34 13.8%
  • 4. Great (golfing panther)

    Votes: 5 2.0%

  • Total voters
    247

dlaloum

Major Contributor
Joined
Oct 4, 2021
Messages
3,324
Likes
2,580
That makes sense to me. Since you mentioned "..a bunch of speculation..", I would say that one good thing about such test results is that because of such tests, we don't have to speculate as much. As you pointed out, a lot of the owners are not experiencing the "ramifications", and that's not surprising because it could simply be that in their usage, the "pull back" behavior Amir found, might not have been triggered, or triggered but not noticed by the owner (as Amir found, there was no indicators). Just like your specific speakers did not do well with your Integra and you noticed it, yet other owners may not (unless the unit actually shutdown).

Having seen the test results, potential owners can make a more informed decision. For example, if I had the kind of uncommon impedance/phase angle characteristics speakers like yours, the RZ50, and its Pioneer, Integra cousins would not be my choice. Since I don't have such speakers and have no plan to acquire anything like them, the RZ50 would be on my short list if I needed an AVR.

In my opinion, ASR is a good place for people who prefer objective measurements to help them make their choices. Those who don't like the results and/or questioned their values would still benefit from the information, that again, should help them in making more informed decisions such as to avoid the DUT (the LX505 in this case), or not, based on their needs.
Quite....

However my analysis of AVR's and Prepros around this price level, did not indicate any that would provide confidence with their ability to handle my speakers - ultimately all contenders were suspect in terms of very low impedance handling.... so then it became an issue of their suitability to run surround/height channels, and effectiveness as pre-amps / processors. (ie: after my initial analysis, I was fairly sure that I would need to use my power amps regardless which AVR I went with... unless I was willing to go up to a much higher price category - and even then...)

Shortlist ended up with Anthem, Denon and Onkyo/Integra.... I wanted to move away from Audyssey.... and then decided I preferred to try out Dirac based on the many positive reviews I was reading (and a couple of impressive listening sessions at audio shows a few years back).

So, not overly concerned about the power amp weaknesses - and the processing and sound quality strengths are excellent.
 

peng

Master Contributor
Forum Donor
Joined
May 12, 2019
Messages
5,928
Likes
5,502
Quite....

However my analysis of AVR's and Prepros around this price level, did not indicate any that would provide confidence with their ability to handle my speakers - ultimately all contenders were suspect in terms of very low impedance handling.... so then it became an issue of their suitability to run surround/height channels, and effectiveness as pre-amps / processors. (ie: after my initial analysis, I was fairly sure that I would need to use my power amps regardless which AVR I went with... unless I was willing to go up to a much higher price category - and even then...)

Shortlist ended up with Anthem, Denon and Onkyo/Integra.... I wanted to move away from Audyssey.... and then decided I preferred to try out Dirac based on the many positive reviews I was reading (and a couple of impressive listening sessions at audio shows a few years back).

So, not overly concerned about the power amp weaknesses - and the processing and sound quality strengths are excellent.

Of course, the test results show for use as prepro that is fine but for use as avr, it depends, and one will have examine the results carefully and then decide if it can meet one's requirement.
 

JSmith

Master Contributor
Joined
Feb 8, 2021
Messages
5,417
Likes
14,144
Location
Algol Perseus
The indicator is in the web GUI menu, so this is kind of clear situation.
The indicator is for protection mode... this is power limiting we're talking about. The amp doesn't shut off... it continues in a lower max power state until restarted.

index.php



JSmith
 

DavidMcRoy

Addicted to Fun and Learning
Joined
Jul 10, 2018
Messages
603
Likes
1,049
The indicator is for protection mode... this is power limiting we're talking about. The amp doesn't shut off... it continues in a lower max power state until restarted.

index.php



JSmith
That's an important distinction. In the case of a "similar" VSX-LX503 being used as a processor only, the entire unit shuts down after some period of time with steady-state signals such as pink noise or sine waves feeding the input or inputs, such as during "manual" room correction tests. I'm curious whether other "similar" Pioneer AVRs in the series behave that way. Again, this is when the amplifiers have no load attached.
 
Last edited:

dlaloum

Major Contributor
Joined
Oct 4, 2021
Messages
3,324
Likes
2,580
The indicator is for protection mode... this is power limiting we're talking about. The amp doesn't shut off... it continues in a lower max power state until restarted.

index.php



JSmith
This is an assumption - we don't actually know what this indicator is triggered by.
 

ivo.f.doma

Active Member
Joined
Jan 21, 2021
Messages
221
Likes
96
Location
Slovakia
This is an assumption - we don't actually know what this indicator is triggered by.
Try putting pink noise or a sine signal into your receiver (of course with disconnected external amplifiers) and observe what happens after 35 seconds. Whether it will be reflected in the PC interface. If I had such a receiver at home, I would try it...
 

peng

Master Contributor
Forum Donor
Joined
May 12, 2019
Messages
5,928
Likes
5,502
Try putting pink noise or a sine signal into your receiver (of course with disconnected external amplifiers) and observe what happens after 35 seconds. Whether it will be reflected in the PC interface. If I had such a receiver at home, I would try it...

Should hook up a multimeter to monitor the output voltage to know at what voltage the limiting took effect
 

Rottmannash

Major Contributor
Forum Donor
Joined
Nov 11, 2020
Messages
3,003
Likes
2,655
Location
Nashville
So I could use REW to send white noise to my RZ50 and watch the web interface and see how long it takes to shut down? How would I know how high to turn the volume? 0dB?
 

peng

Master Contributor
Forum Donor
Joined
May 12, 2019
Messages
5,928
Likes
5,502
So I could use REW to send white noise to my RZ50 and watch the web interface and see how long it takes to shut down? How would I know how high to turn the volume? 0dB?

Amir did not get it to shutdown. So we don't know, it's now up to you to find out.:) It may not even work as suggested using REW because REW may not let you output a high enough signal, and since the Pioneer would go into "limiting", you may not be able to get it to trigger "protection mode" that will shut down the unit, that is, going into standby, unless you can simulate a thermal overload or overcurrent/short circuit event.
 

Doodski

Grand Contributor
Forum Donor
Joined
Dec 9, 2019
Messages
22,152
Likes
22,442
Location
Canada
Amir did not get it to shutdown. So we don't know, it's now up to you to find out.:) It may not even work as suggested using REW because REW may not let you output a high enough signal, and since the Pioneer would go into "limiting", you may not be able to get it to trigger "protection mode" that will shut down the unit, that is, going into standby, unless you can simulate a thermal overload or overcurrent/short circuit event.
Slow 'er down there Ace...Lol. Run this as loud as you dare until it triggers the protection Nanny. It's a 440Hz sine wave that won't be uncomfy to crank but it will draw power. See if this bad boy triggers.
 

peng

Master Contributor
Forum Donor
Joined
May 12, 2019
Messages
5,928
Likes
5,502
Slow 'er down there Ace...Lol. Run this as loud as you dare until it triggers the protection Nanny. It's a 440Hz sine wave that won't be uncomfy to crank but it will draw power. See if this bad boy triggers.

May be may be not, we don't know how that "limiting", or "pull back"as Amir called it work.. When "cranking", you have to do it in such a way that it will get pass the "limiting/pull back", and go straight to the protect mode.
 

Doodski

Grand Contributor
Forum Donor
Joined
Dec 9, 2019
Messages
22,152
Likes
22,442
Location
Canada
May be may be not, we don't know how that "limiting", or "pull back"as Amir called it work.. When "cranking", you have to do it in such a way that it will get pass the "limiting/pull back", and go straight to the protect mode.
If it is a crowbar configuration it might trip, pull back or trigger/limit. Yamaha schematics are available and they show the 4 Ohms limiting and power output drawback is done in the Volume IC. Pioneer may be doing it this way too.
 

peng

Master Contributor
Forum Donor
Joined
May 12, 2019
Messages
5,928
Likes
5,502
If it is a crowbar configuration it might trip, pull back or trigger/limit. Yamaha schematics are available and they show the 4 Ohms limiting and power output drawback is done in the Volume IC. Pioneer may be doing it this way too.

Possibly, might also be done by limiting the input signal. The suggested test can at least confirm as Amir said, that there would be no indicator on the web UI for the pull back event, or there is, however unlikely.
 

Doodski

Grand Contributor
Forum Donor
Joined
Dec 9, 2019
Messages
22,152
Likes
22,442
Location
Canada
might also be done by limiting the input signal.
What difference would this make? Input IC Vs Volume IC? Input circuitry would benefit by not attenuating at all and the Volume IC presumably has DSP within.
 

DavidMcRoy

Addicted to Fun and Learning
Joined
Jul 10, 2018
Messages
603
Likes
1,049
Just do what I've done countless times with a VSX-LX503: feed it pink noise at -10dB on any channel with the volume set at say, -21 or so on the front panel display with NO speakers attached. After a while you'll start hearing a series of relay clicks in the AVR. During this sequence, (it'll take several minutes...far longer than 35 seconds) the whole unit will shut down.

Maybe some of those relay clicks before shutdown are associated with the engagement of the "power limiting" mode?
 
Last edited:

Doodski

Grand Contributor
Forum Donor
Joined
Dec 9, 2019
Messages
22,152
Likes
22,442
Location
Canada
My guess would be that supply rails are reduced to make this happen. At least this is what I would do. As such, the schematic may be revealing there.
I am presuming you are on the platform/floor of a IC in design mode...Lol. I just look as far as the service manual flowcharts and layout for ICs and determine what kind of operation is occurring internally. :D
 

peng

Master Contributor
Forum Donor
Joined
May 12, 2019
Messages
5,928
Likes
5,502
What difference would this make? Input IC Vs Volume IC? Input circuitry would benefit by not attenuating at all and the Volume IC presumably has DSP within.
Many volume ICs dont have dsp build in, such as D+M's NJU72343.
 

peng

Master Contributor
Forum Donor
Joined
May 12, 2019
Messages
5,928
Likes
5,502
My guess would be that supply rails are reduced to make this happen. At least this is what I would do. As such, the schematic may be revealing there.

If they lower the rail voltage, the power amp will clip sooner, and the preout SINAD would likely drop quickly like the Denon AVRs did in your measurements on them.

The Pioneer's preout SINAD remained high during the pull back, so I think Doodski's is more likely right, that the limit is done on the input signal to the power amp, effectively lowering/limiting the gain, instead of the rail voltage.

We are just guessing though.
 
Last edited:

dlaloum

Major Contributor
Joined
Oct 4, 2021
Messages
3,324
Likes
2,580
My guess would be that supply rails are reduced to make this happen. At least this is what I would do. As such, the schematic may be revealing there.
I don't believe anyone has seen the current generation schematics yet...

Has anyone seen the previous generation schematics (should be well nigh identical!) - LX504?
 
Top Bottom