Audiosciencereview.com/. legit?

Pogre

Pogre

Audioholic Warlord
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..:D:D
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

RichB

Audioholic Field Marshall
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/forum/index.php?threads/review-and-measurements-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
 
P

PENG

Audioholic Slumlord
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

RichB

Audioholic Field Marshall
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

slipperybidness

Audioholic Spartan
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

RichB

Audioholic Field Marshall
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
 
P

PENG

Audioholic Slumlord
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

Verdinut

Audioholic Samurai
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

RichB

Audioholic Field Marshall
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/forum/index.php?threads/review-and-measurements-of-marantz-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
 
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slipperybidness

slipperybidness

Audioholic Spartan
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.
 

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