No, in fact the more aggressive the approach such protect mode adopt, such as the alleged limp mode, the more UL would like it.
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Onkyo TX-RZ30 AV Receiver Review
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I have no idea of the opinion of UL and agree they may prefer this approach.
The way I read post #175 from Amir, the Onkyo TX-RZ30 AVR would fail testing at UL if the AVR provided an alert that indicated it is running at less power than specified.
If I am reading that post correctly, it would seem Onkyo would have an incentive to not provide an alert.
I am grateful the AVR brands controlled by Harman International have not adopted the protection protocol created by Onkyo and retained by Premium Audio Corporation.
Alice of Old Vincennes
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Make sure you have ventilation.
He might just be teasing but if he’s serious then I would have to disagree.I have no idea of the opinion of UL and agree they may prefer this approach.
The way I read post #175 from Amir, the Onkyo TX-RZ30 AVR would fail testing at UL if the AVR provided an alert that indicated it is running at less power than specified.
If I am reading that post correctly, it would seem Onkyo would have an incentive to not provide an alert.
I am grateful the AVR brands controlled by Harman International have not adopted the protection protocol created by Onkyo and retained by Premium Audio Corporation.
May I ask what preamp are you using?
What do you think of Andrew Robinson's revelation that ART is not possible on the RZ30?
youtube.com/watch?si=Yur0PLZZhBkJhWMV&t=399&v=k743Kr9akNo&feature=youtu.be
Related to Amir's discovery and/or DSP? So much for the so-called rule that anything that can run DLBC can also do ART!
Cogito
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Emotiva XSP-2 Gen.2
For anyone with the same questions that I had here:
Here's Onkyo's response since I reached out directly to them for the answer:
(Gabriel from Onkyo) -
"In your TX‑RZ30, the internal amplifier stages remain powered but essentially idle when no speakers are connected, so with an open circuit they do not deliver output current and therefore only draw their normal bias (quiescent) current, which produces minimal heat compared to driving a load; because of this, high “volume” settings in pre‑out use do not meaningfully increase thermal stress on the unused power stages since no real power is being delivered to speaker outputs, and protect mode is not expected to trigger under these conditions unless there is an internal fault (e.g., abnormal DC offset, rail instability, or overheating due to ventilation issues), as protection circuits in these designs typically monitor output current, temperature sensors, and voltage anomalies rather than the absence of load, and there is generally no firmware mechanism that looks for or reacts to “idle/no speaker” conditions specifically—so in practical terms, running the RZ30 as a pre‑processor with no speakers connected is thermally safe as long as the unit has proper airflow and is not enclosed in a heat‑trapping environment."
Here's Onkyo's response since I reached out directly to them for the answer:
(Gabriel from Onkyo) -
"In your TX‑RZ30, the internal amplifier stages remain powered but essentially idle when no speakers are connected, so with an open circuit they do not deliver output current and therefore only draw their normal bias (quiescent) current, which produces minimal heat compared to driving a load; because of this, high “volume” settings in pre‑out use do not meaningfully increase thermal stress on the unused power stages since no real power is being delivered to speaker outputs, and protect mode is not expected to trigger under these conditions unless there is an internal fault (e.g., abnormal DC offset, rail instability, or overheating due to ventilation issues), as protection circuits in these designs typically monitor output current, temperature sensors, and voltage anomalies rather than the absence of load, and there is generally no firmware mechanism that looks for or reacts to “idle/no speaker” conditions specifically—so in practical terms, running the RZ30 as a pre‑processor with no speakers connected is thermally safe as long as the unit has proper airflow and is not enclosed in a heat‑trapping environment."
OP
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That safety must be achieved at the rated power. Otherwise people could run the test at 5 watts and everything would pass.
Just 2 points to make:
1). The RZ30 is rated 100 w, into 8 ohms, 2 channels driven so if you don’t push it past that point it would have passed the test, in terms of “safety” that UL focusses on.
2). Regardless, the RZ30 is UL approved. Now you may argue that UL did not know about the limp mode, that I believe UL wouldn’t care about that because it is a protect mode, not a normal operating condition, but if so, I would just have to agree to disagree with you Lol, no big deal..
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Indeed. Cheap, plasticky build as well. Most $500 AVRs from 20 years ago have better build than AVRs of today up to $2k. And it all started with the introduction of HDMI.
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Ugh, HDMIIndeed. Cheap, plasticky build as well. Most $500 AVRs from 20 years ago have better build than AVRs of today up to $2k. And it all started with the introduction of HDMI.
The performance of AVR amplifiiers from Premium Audio Corporation - as measured by Amir - is enough to recommend an alternative AVR from Denon.
While only some Denon AVR's are compatible with Dirac Live, many more are compatible with the $19.99 Audessey MultEQ Editor app that Amir recommends:
Audyssey Room EQ Review
This is a review and detailed measurements of the Audyssey Room Equalization. Audyssey is standard technology in a number of Audio/Video Receivers such as the Denon AVR-X3600H I recently reviewed. The standard version in the AVR is mostly all or nothing so I downloaded the Marantz/Denon...
www.audiosciencereview.com
OP
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Given this, it reminds me of another theory: they are checking to see if the Amp every clips. If so, they reduce the power in order to make sure the amp doesn't get damaged in the future.
Alice of Old Vincennes
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Wow
#1 is the only thing the RZ30 is rated for and that is all that matters for UL. As I've said many times, unless the FTC decides to make it mandatory to force OEMs to report rated power into 4 ohms, there's no reason for Onkyo to do more than it needs to. Otherwise, it would be at a complete disadvantage against the likes of D&M and other brands! It's only during the arms race to bring ART to the table that the current RZ deficiencies were laid bare!
Based on what Andrew Robinson said, it seems like nothing but a complete overhaul of the RZ circuitry, DSP, and perhaps beefier heatsinks, will allow the RZ models to run ART!
The point I disagree with Amir is only on his idea that somehow if Onkyo had provided an alert of some sort to the user if and when the limp mode is triggered, that seemed to say that if Onkyo had done that it would not pass UL.
His post#175:
"If that message alerts them to the fact that the unit is not running at full power, then it would nullify their specifications and hance fail the test."
To me, UL wouldn't care about whether there is an alert in this specific case, and if they did (highly unlikely), it would not be a good reason for Onkyo to skip such as alter. The limp mode is only triggered if the user pushes the RZ30 to a certain point such as the one Amir did in his test, in trying to find the clipping point I assume... For example, Amir stated "As a result of this, I can't run any of my power rating tests as they rely on finding the clipping point." So, let's say he didn't bother trying to find the clipping point, but simply test the amp at up to 100 W into 8 ohms, the limp mode would not have been triggered right?
Once a protect mode is triggered, and in this case, it would not shutdown but would limit the output. In this case, I am simply suggesting that some sort of indication such as on screen message, lit LED light on e unit's display would be better than not alerting the user at all. Other then that I have no disagreement with anyone on the good and/or bad of the limp mode itself.
Amir
Ok, but that level of transparency would certainly cost Onkyo sales, would it not?
I went ahead and bought the RZ30 anyway. I have pushed the crap of this receiver in huge room and it has not entered protect mode once. Granted I’m running all Paradigm Premier speakers that large efficient 8ohm speakers. I am thankful to Amir for making me aware of this one shortcoming. I agree the RZ lineup should have a notification on the front of the receiver if it does go into protect mode. So far this receiver has surpassed my expectations. I’m a happy camper!
If you want to test how challenging your speakers are you can do the following:
1) Play a well known movie or audio track (to you) at a moderately high volume so that you can appreciate the details and dynamics. Note the general dB level (with an SPL meter, Apple Watch, etc.) so that you can volume match in the next step.
2) Flip to 4 ohm mode on the impedance switch (no harm in doing this). Play the same track again and steadily increase the volume until you reasonably match the dB level of step 1.
3) Once volume matched, listen for the same details and dynamics in this mode. Return to default selection on impedance switch when done.
If there is no difference in dynamics/details - "unintended 4 ohm mode" is already active and your speakers are challenging for the RZ30. Remember, there will be no indication you are in this mode. You will have to unplug and plug to bring it back to life for normal usage.
If there is a difference in dynamics/details - Your speakers are most likely 8 ohms nominal and don't present a challenge to the RZ30. It is "normal" to expect a difference when the impedance switch has been flipped!
I'm on the fence concerning if the volume levels should be the same when doing the critical listening but it sounds right at least.
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