Audiosciencereview.com/. legit?

[Pogre]

By the way, I don't know about you and I forgot if you have the Denon or Marantz AVR, but I think guys like HD and ADTG would have read the link I provided to that very article by Dr. Rich on the AV8801 vs AV8802A, and about the damn HDAM that has been discussed to almost the nth degree. So to them, or you included, that's nothing new.. can't resist, but sarcasm not intended..

Yeah, I have an SR6011.

I read everything you guys post. Do I understand most of it? Nope! But I read it. This had potential to be a great conversation and learning opportunity for me. I was following from page 1.

 

[RichB]

True, such as there is no standard definition for the term “rated output voltage”, we can agree or disagree on somebody’s opinion about it. I agree with those engineer’s opinions (google for quora),they are responses for the question about this term. You disagree? That is fine. Use your own definition - whatever it is.
My definition of the “rated voltage output” is the same as provided by Answer WIKI:
“Rated means the maximum for which the device is intended”. Google “rated voltage output” and you will find the quora’s definition and discussions.

I believe there was an analysis of the devices and it was clear that the 8805 can output >4 volts.
Here is the thread:

https://www.audiosciencereview.com/...urements-of-marantz-av8805-av-processor.6926/
There is a lot of dross but there is good data.

I suspect the 8805 specs provide2.4 volts rated output to provide lower distortion.

Manufacturers are rarely providing specifications that include voltage into load with distortion.
According to @buyguyca on AVSForum, it is common to rate outputs into 100K Ohms which rarely occurs.
Input impedance is typically 10K to 50K so distortion will likely be higher than specified (when specified).

Preamps with higher output voltage and low distortion should provide good performance driving a variety of amplifiers.

- Rich

 

[PENG]

I suspect the 8805 specs provide2.4 volts rated output to provide lower distortion.

Yes, but the measured THD+N were still well below the specified 0.005%, by either hometheaterhifi on the 8802A or Audiosciencereview on the 8805.

Even at 4.95 V XLR, the 8802A's measured THD (hometheaterhifi.com) was only 0.003578% THD+N in the 10 kHz sine wave test and 0.002056% in the 1 kHz test, HDMI input (analog input similarly good).

The reviewer noted: With 2 VRMS balanced as shown in the previous graph, you only have 1 VRMS single ended, which is what runs internally inside the AV8802. In this test, we have 2.07 VRMS single ended with no increase in distortion which is excellent.

I think it is fair to say based on available bench test results, Marantz could have "rated" the pre out voltage at least twice as high, if distortions was the consideration. To know what really is the reason for the 1.2/2.4 V spec, someone needs to email Marantz customer service and insist that they forward it to their engineering team. I did that once, about the issue on the filter setting related distortion spike and they did response within 10 days. So I may do it again on pre out spec question.

This is really an academic discussion as even the specified 0.005% should be well below the audibility threshold.

 

[RichB]

Yes, but the measured THD+N were still well below the specified 0.005%, by either hometheaterhifi on the 8802A or Audiosciencereview on the 8805.

Even at 4.95 V XLR, the 8802A's measured THD (hometheaterhifi.com) was only 0.003578% THD+N in the 10 kHz sine wave test and 0.002056% in the 1 kHz test, HDMI input (analog input similarly good).

The reviewer noted: With 2 VRMS balanced as shown in the previous graph, you only have 1 VRMS single ended, which is what runs internally inside the AV8802. In this test, we have 2.07 VRMS single ended with no increase in distortion which is excellent.

I think it is fair to say based on available bench test results, Marantz could have "rated" the pre out voltage at least twice as high, if distortions was the consideration. To know what really is the reason for the 1.2/2.4 V spec, someone needs to email Marantz customer service and insist that they forward it to their engineering team. I did that once, about the issue on the filter setting related distortion spike and they did response within 10 days. So I may do it again on pre out spec question.

This is really an academic discussion as even the specified 0.005% should be well below the audibility threshold.

It is not entirely academic for those that want to properly gain match their amplifiers. Consumers have to wait for review site measurements which are inconsistently available.

Performance specifications are, at best, incomplete for many of these (IMO) expensive processors. For Marantz, they are buried in the manual and not posted on their website.

- Rich

 

[slipperybidness]

It is not entirely academic for those that want to properly gain match their amplifiers. Consumers have to wait for review site measurements which are inconsistently available.

Performance specifications are, at best, incomplete for many of these (IMO) expensive processors. For Marantz, they are buried in the manual and not posted on their website.

- Rich

It's not too difficult nor too costly for the equipment to measure the full range output before clipping. You could likely find a local community college that would assist with that, if it were that important to you.

Adding the THD+N measurement is a bit more difficult.

 

[RichB]

It's not too difficult nor too costly for the equipment to measure the full range output before clipping. You could likely find a local community college that would assist with that, if it were that important to you.

Adding the THD+N measurement is a bit more difficult.

If you are for standardized amplifier power specifications, then standardized preamplifier specifications should also be supported.
Certainly manufacturers of processors that list for over $3000 should not be devoid of meaningful specifications.

It is ridiculous to expect consumers to gain access to a bunch of multi-thousand dollar processors and send then to a bunch of college interns.

- Rich

 

[PENG]

It is not entirely academic for those that want to properly gain match their amplifiers. Consumers have to wait for review site measurements which are inconsistently available.

Performance specifications are, at best, incomplete for many of these (IMO) expensive processors. For Marantz, they are buried in the manual and not posted on their website.

- Rich

I meant the THD between the specified 0.005% and the measured values by ASR and HTHF were academic.
I agree the pre out specs are important, in fact very important. In fact I felt compelled to email Marantz for more info.

 

[Verdinut]

It is not entirely academic for those that want to properly gain match their amplifiers. Consumers have to wait for review site measurements which are inconsistently available.

Performance specifications are, at best, incomplete for many of these (IMO) expensive processors. For Marantz, they are buried in the manual and not posted on their website.

- Rich

Some specs are buried in the manual, but isn't the manual reachable on the manufacturer's website anyway?

But one of the most important specs, the max. output voltage before clipping is not published, is it?

 

[RichB]

Some specs are buried in the manual, but isn't the manual reachable on the manufacturer's website anyway?

But one of the most important specs, the max. output voltage before clipping is not published, is it?

Technically, the specs can be found in the manual that is viewed online in the appendix.
They cannot be found on the "Specifications" tab on the web site. This seems to be the trend for "high end" products.

Correct. The output voltage before clipping is not published and first learned of the high voltage output from the audiosciencereview.com.
Here is a post illustrating the need for accurate output voltage for amplifier matching. Clearly, a good specification is required for consumers:

https://www.audiosciencereview.com/...-av8805-av-processor.6926/page-17#post-174117

can't find a review of Marantz AV8805 in there. They only have AV8802 which may be a different design. Regardless, they say right in the review: https://hometheaterhifi.com/reviews/receiver-processor/processors/marantz-av8802-processor-review/

You see in black and white that 2 volts is not proper for XLR output. And why they tested at 5 volt which is even higher than what I tested.



ProFan said:


Bryston 4b sensitivity at 1.4V for 250W at 8 ohm (it has switchable gain 23dB or 29dB).

Not correct. From the manual:

You need 3.46 volts for full power in low gain mode, not 1.4 volt. Even in high gain you won't achieve full power at 1.4 volts (1.73 volts is needed).

Regardless, there are no standards for power amplifier gain. Since XLR is a professional standard, let's go to venerable rane.com for verification: https://www.rane.com/note135.html

4 dBu = 1.2 volts. 20 dBu = 7.7 volts (RMS).

So as you see, 4 volts RMS that I test at is not at all extreme.

Bottom line: my reviews don't cater to spec verification. They follow standardized norms and apples vs apples comparison. We can't grade on a curve especially when we are talking such an expensive processor.

Oddly enough, Marantz is better than others.
Currently, the Emotiva RMC-1 has no performance specifications. Nothing for Storm Audio. I am sure there are more examples.

- Rich

 

[slipperybidness]

If you are for standardized amplifier power specifications, then standardized preamplifier specifications should also be supported.
Certainly manufacturers of processors that list for over $3000 should not be devoid of meaningful specifications.

It is ridiculous to expect consumers to gain access to a bunch of multi-thousand dollar processors and send then to a bunch of college interns.

- Rich

Yeah, fair enough, the specs should be provided by the mfg, especially after a certain price point.

But, I will always trust my own measurements vs. a published spec. And, that work is not for everyone.

I have never gotten into a situation that I felt the need to measure the output of a commercial pre-amp, only on DIY designs to confirm that I hit the target gain.

 

[jinjuku]

Amir dosn't have the horsepower that Stereophile & TAS have. He can't push manufactures around. He's doing the tests on his own time and out of his own pocket (with sample units from friends). He doen't have a staff of employees to keep track of loose ends.

Fast forward two years and my how things have changed. Manufacturers from Denon to Schiit have taken notice. Schiit even purchased an AP analyzer and their $249 Modius DAC is a direct result of Amir's influence in the industry.

 

[PENG]

Fast forward two years and my how things have changed. Manufacturers from Denon to Schiit have taken notice. Schiit even purchased an AP analyzer and their $249 Modius DAC is a direct result of Amir's influence in the industry.

He just got Anthem's attention too, after reviewing/measuring the AVM60. Many people there are anxiously awaiting Anthem's response, also hoping to get an AVM70 to review, if the AVM60's measurements are in fact non SOTA.

 

[Pogre]

I totally lurk at asr. I don't have an account there, but there's a lot of good info in his tests and measurements. What's been happening with him getting the attention of some heavy hitters is a good thing for we consumers, and it's interesting following along.

 

[RichB]

He just got Anthem's attention too, after reviewing/measuring the AVM60. Many people there are anxiously awaiting Anthem's response, also hoping to get an AVM70 to review, if the AVM60's measurements are in fact non SOTA.

So what is SOTA?
I think the CD resolution lets the panther keep his head.

- Rich

 

[lovinthehd]

Hard to know what's SOTA unless every unit available out there is tested for comparison....but does seem several unhappy people that it's not the SOTA that they feel Anthem has claimed.....

 

[Pogre]

Hard to know what's SOTA unless every unit available out there is tested for comparison....but does seem several unhappy people that it's not the SOTA that they feel Anthem has claimed.....

It still tickles me that a lowly avr we commonly recommended is one of the best measuring integrated/prepros he's tested.

 

[RichB]

It still tickles me that a lowly avr we commonly recommended is one of the best measuring integrated/prepros he's tested.

I am more ticked at the other AVRs than tickled.

Center channel testing is needed to make an informed decision since this represents 80% of the sound. Also, not testing is performance with processing engaged.
I say this as an X3700H owner. I can tell you that Dolby Surround up mixing of 2.0 content is astoundingly good on the RMC-1. On the X3700, it sounds like the old PLII. I don't know why but I do know that the RMC-1 the same DACs and implementation on all channels. I have no idea about the X3700 DAC/DSP implementation.

ASR is doing a great job measuring products but only in Direct/Pure 2-channel mode which provides baseline performance. That is enough to determine that there is room for improvement. However, I would necessarily conclude that other channels measure as well.

- Rich

 

[lovinthehd]

The ASR testing is fairly limited....it is what it is. An indicator perhaps. How you subjectively react who knows.

 

[Pogre]

I am more ticked at the other AVRs than tickled.

Center channel testing is needed to make an informed decision since this represents 80% of the sound. Also, not testing is performance with processing engaged.
I say this as an X3700H owner. I can tell you that Dolby Surround up mixing of 2.0 content is astoundingly good on the RMC-1. On the X3700, it sounds like the old PLII. I don't know why but I do know that the RMC-1 the same DACs and implementation on all channels. I have no idea about the X3700 DAC/DSP implementation.

ASR is doing a great job measuring products but only in Direct/Pure 2-channel mode which provides baseline performance. That is enough to determine that there is room for improvement. However, I would necessarily conclude that other channels measure as well.

- Rich

He did measure the center I ordered to go with my towers, an Ascend Acoustic Horizon with a ribbon tweet and it actually did pretty well. He still says he doesn't like it, but acknowledgedes it's pretty well behaved.

Even tho he didn't recommend I still say it did really well and am satisfied with the results. Just gotta read between the lines (or skip right over a bunch of them) when you're looking at his reviews.

 

[AcuDefTechGuy]

Fast forward two years and my how things have changed. Manufacturers from Denon to Schiit have taken notice. Schiit even purchased an AP analyzer and their $249 Modius DAC is a direct result of Amir's influence in the industry.

I agree with HD.

There is no denying that some companies are getting involved now that ASR almost has the “monopoly“ on electronics measurement - I still don’t understand why everyone just quit doing measurements.

But the true test would be to correlate those ASR SOTA numbers with actual sales numbers since they don’t correlate with things like Sound Quality, Reliability, Compatibility, Functionality, etc., at least among NON-golden-ears people.