Pioneer VSX-LX505 AVR Review

[Audio Science Pal]

Hopefully these screenshots are enough to satisfy that with DLBM, you can choose XO for each group (fronts, center, surround pairs, height pairs, etc.).

Front Left/Right
View attachment 357734

Center
View attachment 357735

Surrounds
View attachment 357736

Front Heights
View attachment 357737

That is interesting.

 

[Kachda]

Does anyone know why I am unable to change the delays on the AVR ? I used to be able to set the distance in feet manually, but after I ran Dirac Live, it seems to have switched the delay to msec, and I am unable to move the sliders or change the delay through web interface or the AVR menu. The problem is that these delays aren't correct, and I can definitely hear echoes instead of a seamless music now.

 

[Johnp]

Does anyone know why I am unable to change the delays on the AVR ? I used to be able to set the distance in feet manually, but after I ran Dirac Live, it seems to have switched the delay to msec, and I am unable to move the sliders or change the delay through web interface or the AVR menu. The problem is that these delays aren't correct, and I can definitely hear echoes instead of a seamless music now.

View attachment 359106

That is just how it is once Dirac is loaded on this unit. You cannot adjust distances.

 

[pras1011]

Is the 805 any better?

 

[MisterT3]

As an electrical Engineer, can you take the thing apart and tell us what relay this is and why it is switching? (cannot find the service manual, either)
What happens to the power drawn by the Receiver?

I have experienced/heard the switching after several dozen or so minutes of just playing background music.. sounds to me like the amp just switching off certain things, cranking down the internal stuff because it's not needed.

But what you describe appears to be something different entirely. As if the amp tried to protect itself.
Did you drive output past 0dB setting (Volume control), too?
How did you measure the signal with 8 Ohms loads? (I'm no electrical engineer, just trying to understand the implications of this for real people)

Now, 25 Watts for me is 96dB from a single speaker.. that's basically the peak SPL I would expect when playing a movie on the -10dB setting (105dB is reference level)
never for 30 seconds straight, though..
But I really want to understand how these things come to be, because the amplifier has more than enough power from the psu (700+ Watts) and it was rated at 100+ Watts per channel and actually measured by acclaimed audio magazines to put out the rated amount of power into 5/7 channels respectively.
View attachment 358426

This relay activates ("the click") from thermal or detection of large signal, dont know.. My bet is that the relay switches a different set of secondary windings on the main power transformer that lowers the bipolar supply rails to the class AB amps, limiting power. If I could find a service manual I would see if a simple circuit board hack could disable current through that relay coil.. In that case I would purchase this AV in a heartbeat, as the price/performance is very good..

 

[MbphotoX]

This relay activates ("the click") from thermal or detection of large signal, dont know.. My bet is that the relay switches a different set of secondary windings on the main power transformer that lowers the bipolar supply rails to the class AB amps, limiting power. If I could find a service manual I would see if a simple circuit board hack could disable current through that relay coil.. In that case I would purchase this AV in a heartbeat, as the price/performance is very good..

according to @popej this might be the reason:
"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."

Now, the question that remains, at least to me, would be:
does this at all matter?!

It normally happens when you don't actually NEED any power from the AVR, so it basically goes into eco mode.
As soon as you draw more power by increasing the volume, the relay switches back to high power mode.

 

[dlaloum]

This relay activates ("the click") from thermal or detection of large signal, dont know.. My bet is that the relay switches a different set of secondary windings on the main power transformer that lowers the bipolar supply rails to the class AB amps, limiting power. If I could find a service manual I would see if a simple circuit board hack could disable current through that relay coil.. In that case I would purchase this AV in a heartbeat, as the price/performance is very good..

Lots of use have been hoping to see service manuals for the current generation - so far they are unobtainium

 

[fadetoblackbs]

Anybody uses the „Height 1“ connectors for Bi-Amping? Looks like it is possible seeing the labeling on the back (see attached picture).
Did you achieve better results?
Thanks.

 

[EWL5]

Anybody uses the „Height 1“ connectors for Bi-Amping? Looks like it is possible seeing the labeling on the back (see attached picture).
Did you achieve better results?
Thanks.
View attachment 378250

Based on Amir's review, I highly recommend not bi-amping (especially if you have low impedance speakers)!

 

[Chrispy]

Anybody uses the „Height 1“ connectors for Bi-Amping? Looks like it is possible seeing the labeling on the back (see attached picture).
Did you achieve better results?
Thanks.
View attachment 378250

It's just the same signal to each set of speakers, and you still have the passive crossover in your speaker, too.....waste of wire IMO.

 

[dlaloum]

It's just the same signal to each set of speakers, and you still have the passive crossover in your speaker, too.....waste of wire IMO.

The PiOnkIo's have true BiAmping, in that you can set an onboard crossover, and the signal sent to the two outputs is therefore frequency limited accordingly.

I have used them this way in the past... there were no substantive benefits in my use case... I also tried with external line level LP/HP filters and external amps as well as external amps with onboard DSP crossovers.... in all of these cases I found benefits were very slight and might have been imaginary. (did those experiments about 15 years ago.... before I had measurement mic's... features of this manufacturers AVR's in this area have been well nigh the same for many many years)

 

[Chrispy]

The PiOnkIo's have true BiAmping, in that you can set an onboard crossover, and the signal sent to the two outputs is therefore frequency limited accordingly.

I have used them this way in the past... there were no substantive benefits in my use case... I also tried with external line level LP/HP filters and external amps as well as external amps with onboard DSP crossovers.... in all of these cases I found benefits were very slight and might have been imaginary. (did those experiments about 15 years ago.... before I had measurement mic's... features of this manufacturers AVR's in this area have been well nigh the same for many many years)

The only models I'm aware of that had this feature were a few Onkyo (maybe Integra) like the 818....didn't realize they brought that back.

 

[dlaloum]

The only models I'm aware of that had this feature were a few Onkyo (maybe Integra) like the 818....didn't realize they brought that back.

The old SR876 and DTR70.4 had it, the current Integra DRX3.4 has it - I assumed it was universal among the current Dirac capable models...

 

[Chrispy]

Was just looking at the LX505 manual, see no indication its any sort of active bi-amping option. I'll go look at the Integra 3.4. The 818 and 919 were the only avrs I can remember where some sort of actual bi-amping was offered (aside from power supply limitations)

 

[Chrispy]

@dialoum, no don't see that as an option on the 3.4 either. I'm pretty sure this feature only briefly existed years back on the 818/919 and related models.....I wanted one at the time

 

[dlaloum]

@dialoum, no don't see that as an option on the 3.4 either. I'm pretty sure this feature only briefly existed years back on the 818/919 and related models.....I wanted one at the time

You could be right - I just went through the manual myself - and nothing there about a crossover....
A bit sad to miss such a simple thing!

 

[Chrispy]

You could be right - I just went through the manual myself - and nothing there about a crossover....
A bit sad to miss such a simple thing!

Mostly its just a marketing thing for both speakers and avrs anyways, relying on silly audiophilia as backup. If you want an active crossover there are alternatives altho incorporating with most current avrs is a challenge....

 

[dlaloum]

Mostly its just a marketing thing for both speakers and avrs anyways, relying on silly audiophilia as backup. If you want an active crossover there are alternatives altho incorporating with most current avrs is a challenge....

With the right AVR, and Dirac DLBC/ART - it is possible (potentially) to use sub channels for the woofer in a biamp setup - with a lot of convenient tuning flexibility.... - but not with this series of AVR's from the look of it.
The RZ70/LX805 should be able to do it... (using external amps)

 

[Chrispy]

With the right AVR, and Dirac DLBC/ART - it is possible (potentially) to use sub channels for the woofer in a biamp setup - with a lot of convenient tuning flexibility.... - but not with this series of AVR's from the look of it.
The RZ70/LX805 should be able to do it... (using external amps)

Uh huh

 

[MbphotoX]

Bi-Amping should still have some effect, even if you don't have an active crossover beforehand, since the signal is separated inside the speaker.
Only problem I see with AVR bi-amping is that the AVR won't necessarily provide the power required by the bass drivers.. It's always the PSU that's limiting.