Marantz SR6014 AVR Review

[peng]

Surprisingly,
my preliminary measurements showed that the frequency response was similar (around -3~-4dB at 20 khz) between sampling rate of 44.1 khz vs 96 khz (HDMI in, speaker terminal out) in my marantz AVR.

Yes. -3~-4dB at 20khz from the sampling rate of 96 khz.

So It seems to me that "flatter to say 28khz" was not a concern for the Marantz.

It is relative, so we would have to compare its FR from 20 to 28,000 Hz will suffice) vs a Denon, using digital input and preferably with sampling frequency of say 48 kHz in order to see which one is "flatter" pass the nyquist frequency . We already know the Denon would not start the roll off until it hit 24 kHz but once that it would drop rapidly, whereas the Marantz would start dropping off sooner but the slope would be gentler. I am not defending the slow roll off filter at all. In fact I prefer the sharp roll off filter. I am just curious to see the FR curves all the way to at least 25 kHz just to see what Marantz might be trying to achieve. May be I misunderstood the whole thing,.

 

[flyhigh]

24bit 44.1khz sampling frequency response

24bit 96khz sampling frequency response

RMAA 6.4.5 software.
PC NVIDIA HDMI in - Marantz AVR - speaker terminal out (No dummy load) - E-mu 0404 (usb model) input
Both direct mode and stereo mode showed similar FR.

I am not sure What Marantz is trying to achieve using the slow roll off filter except for so called "warm sound".

/* EDIT 2020 28 AUG*/ There are updated FRs of 24-96 below.

 

[peng]

View attachment 79499
24bit 44.1khz sampling frequency response

View attachment 79500
24bit 96khz sampling frequency response

RMAA 6.4.5 software.
PC NVIDIA HDMI in - Marantz AVR - speaker terminal out (No dummy load) - E-mu 0404 (usb model) input
Both direct mode and stereo mode showed similar FR.

I am not sure What Marantz is trying to achieve using the slow roll off filter except for so called "warm sound".

I don't understand why the second graph shows no improvements. Did the software do a frequency sweep up to 30 kHz? If it did, why would it start to roll off at about 10 kHz regardless of the sampling frequency 44.1 or 96 kHz?

 

[flyhigh]

I don't understand why the second graph shows no improvements. Did the software do a frequency sweep up to 30 kHz? If it did, why would it start to roll off at about 10 kHz regardless of the sampling frequency 44.1 or 96 kHz?

Me, neither. I will check if there was errors in software or my method at weekend.

 

[peng]

Maybe this explains why Marantz thinks HDAM and other tweaks that lead to slightly higher THD, (of around -85dB to -75dB THD) actually sounds better than minimizing THD.
https://archimago.blogspot.com/2020/06/blind-test-results-part-ii-is-high.html
The data there indicated that more listeners in a blind test preferred music with -75dB THD than -175dB THD. Perhaps a small amount of 2nd and 3rd order harmonics is like salt and pepper on food. Or perhaps it is indistinguishable and was slightly preferred over zero distortion due to chance. But 75dB of THD was clearly not voted as objectionable or inferior to either zero THD or to higher levels of THD (-50dB of THD or more that were generally voted inferior).
The author writes:
"For now, I think that for music listening, if the THD of the reproduction system from source to speaker/headphone is <0.1% (-60dB) across the audible spectrum, the vast majority of listeners would not find this to be objectionable. One might even hear some preferred "euphonic distortion" with low order harmonics around the 0.01-0.1% THD range in my estimation (needs to be tested of course!)."

Such speculation sounded convincing, but apparently has just been shot down by Marantz themselves, perhaps inadvertently, now that we know the SR8015 is capable of near 100 dB SINAD too, whatever they might have done to the 2020 HDAMs. Last time they revised HDAMs was when they launched the AV8802A, SR7009 so that was about 6 years ago. Regardless, if distortion is so low, lower than 0.001% in total, then where are the magical warm sounding harmonics? Nothing apparent in the FFTs either if you compared models prior to 2020. In fact, if anything, the often referred to as warm sounding 2nd harmonics was a little higher in proportion as shown in Denon's FFT!!

Again, all that shouldn't matter at such low level of "total" harmonic distortions. And as I mentioned before, if they had found the HDAM magic, then why not include them n the slimline series? If cost is the reason, then they should have made it clear that the so called "better for music" deal would apply to the non slimline series only.. Bottom line, what they said in that video, if true, would defy logic..

 

[Kanon]

7.1 line inputs

Yes, actually if you use 7.1 ch analog inputs, there is no option for the signal to get digitized. I have not used 7.1 ch analog input for ages so I don't remember much about it but I don't think you can even select any mode. If you press pure direct it would turn the display off, that's about it. With that input, your source player is in control.

I own the 7010 with 7.1 analog channel in. In the 7.1 analog channel mode I can only adjust volume and switching between direct and pure direct. Switching to pure direct will turn off the screen.

 

[A.West]

Such speculation sounded convincing, but apparently has just been shot down by Marantz themselves, perhaps inadvertently, now that we know the SR8015 is capable of near 100 dB SINAD too, whatever they might have done to the 2020 HDAMs. Last time they revised HDAMs was when they launched the AV8802A, SR7009 so that was about 6 years ago. Regardless, if distortion is so low, lower than 0.001% in total, then where are the magical warm sounding harmonics? Nothing apparent in the FFTs either if you compared models prior to 2020. In fact, if anything, the often referred to as warm sounding 2nd harmonics was a little higher in proportion as shown in Denon's FFT!!

Again, all that shouldn't matter at such low level of "total" harmonic distortions. And as I mentioned before, if they had found the HDAM magic, then why not include them n the slimline series? If cost is the reason, then they should have made it clear that the so called "better for music" deal would apply to the non slimline series only.. Bottom line, what they said in that video, if true, would defy logic..

My main takeaway is that audiophiles don't actually find -75db THD objectionable in blind tests. I personally can only differentiate distortion up to about -30db in careful blind tests with headphones. Thus, scientifically and objectively, I shouldn't be in a rush to replace my 6014 due to Amir's pre-out distortion measurements. From an audibility perspective, room correction performance would probably be more relevant for a home theater user like me. Or other features like dynamic volume.

 

[peng]

My main takeaway is that audiophiles don't actually find -75db THD objectionable in blind tests. I personally can only differentiate distortion up to about -30db in careful blind tests with headphones. Thus, scientifically and objectively, I shouldn't be in a rush to replace my 6014 due to Amir's pre-out distortion measurements. From an audibility perspective, room correction performance would probably be more relevant for a home theater user like me. Or other features like dynamic volume.

I really don't have concerns with 75 dB SINAD either as long as it is the worst case condition, such as not less than that for the full audio band 20-20,000 Hz and from 0.001 W to rated output. Having said that I do prefer 80 dB minimum for the pre-outs, just to give the power amp downstream a better chance. Fortunately the 6014 did manage 80 dB iirc. I don't want to pay more for less though, as I did it once when I bought the AV8801(fool me once okay, but twice...not really. My next Marantz (it could still be a Denon, depends.)won't be an AVP, but possibly a SR7015, or more likely SR7016 based on their super sales price in Canada. The SR7012 and 7013 had been down to less than USD 900 on more than one occasions in the last two years.

 

[amirm]

Edit: I also wish to thank the OP for spending many hours for working on such tests. LMK if there is a 'donate' link. I'll leave a small contribution.

Thanks for the kind words. There is a "Donate" tab on top of the forum page or you can click on this: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

 

[bigguyca]

Such speculation sounded convincing, but apparently has just been shot down by Marantz themselves, perhaps inadvertently, now that we know the SR8015 is capable of near 100 dB SINAD too, whatever they might have done to the 2020 HDAMs. Last time they revised HDAMs was when they launched the AV8802A, SR7009 so that was about 6 years ago. Regardless, if distortion is so low, lower than 0.001% in total, then where are the magical warm sounding harmonics? Nothing apparent in the FFTs either if you compared models prior to 2020. In fact, if anything, the often referred to as warm sounding 2nd harmonics was a little higher in proportion as shown in Denon's FFT!!

Again, all that shouldn't matter at such low level of "total" harmonic distortions. And as I mentioned before, if they had found the HDAM magic, then why not include them n the slimline series? If cost is the reason, then they should have made it clear that the so called "better for music" deal would apply to the non slimline series only.. Bottom line, what they said in that video, if true, would defy logic..

It would be best to wait for measurements by Amir in ASR to judge the SR8015. Here is one comparative set of measurements between ASR and Denon. This is a significant difference. At best this is due to different test setups. Measurements using Amir's test setup are required to make valid comparisons between the SR8015 and other AVR's tested by Amir.

Note the experience with the recent Denon X6700H AVR. Denon shipped units with capacitors and who knows what else, that didn't meet Denon's normal standards for the capacitor. No one would have known without the ASR measurements.

Taking President Reagan one step further: Don't trust and do verify.

A Denon marketing guy in a recent YouTube view stated that it is OK to mislead potential customers to obtain sales.

Marantz could certainly improve the circuits that use HDAM's. Normally in Marantz AVR's, a 4-transistor HDAM, then a common emitter voltage gain stage and then another HDAM, with feedback from the output of the circuit to the low impedance node of the input HDAM, form the overall circuit. Resistor based-current source (generally a very poor practice) and +/- 7V power supplies are used.

Use of transistor based current sources and higher supply voltages would likely improve performance of the AVR circuit that uses HDAM's, perhaps to the level of a modest IC opamp. Since modest IC opamps and opamps in CMOS volume controls, are in series with these HDAM circuits, these opamps will limit the performance of the overall circuit even if Marantz begins to include a golden circuit that uses HDAM's. Removal of the HDAM's appears to allow this same level of performance to be met, which all things being equal, would be the performance level already achieved by Denon.

Marantz didn't included a note with the SR8015 measurements to indicate if the DAC reconstruction filter has been changed to meet standards. Changing the filter or allowing a choice of filters would be trivial. A selection of filters is already in the DAC IC (AK4458), only values input to a pin/register on the DAC IC need to be changed to change the filter, a software change.

 

[peng]

7.1 line inputs

I own the 7010 with 7.1 analog channel in. In the 7.1 analog channel mode I can only adjust volume and switching between direct and pure direct. Switching to pure direct will turn off the screen.

Thank you for confirming what I thought I remember.

 

[Urgo]

Do we know if there are any 2020 Marantz's in queue to measure?

 

[flyhigh]

I don't understand why the second graph shows no improvements. Did the software do a frequency sweep up to 30 kHz? If it did, why would it start to roll off at about 10 kHz regardless of the sampling frequency 44.1 or 96 kHz?

24bit 96khz sampling Pure Direct (or Direct) Mode

24bit 96khz sampling Stereo Mode (front small 80Hz, GEQ 16khz +0.5dB setting)

My previous measurement using RMAA had errors. The sampling rate of Windows sound property of marantz AVR(NVIDIA) HDMI output was set at 16-48. When the both sampling rate (windows HDMI output of SOUND, and RMAA internal setting) was changed to 24-96, the above results were shown.

The FR was different between direct (or pure direct) vs stereo modes at 24-96 . The results is disappointing because I do not use direct mode due to subwoofers and other features.

 

[peng]

View attachment 80283
24bit 96khz sampling Pure Direct (or Direct) Mode

View attachment 80284
24bit 96khz sampling Stereo Mode (front small 80Hz, GEQ 16khz +0.5dB setting)

My previous measurement using RMAA had errors. The sampling rate of Windows sound property of marantz AVR(NVIDIA) HDMI output was set at 16-48. When the both sampling rate (windows HDMI output of SOUND, and RMAA internal setting) was changed to 24-96, the above results were shown.

The FR was different between direct (or pure direct) vs stereo modes at 24-96 . The results is disappointing because I do not use direct mode due to subwoofers and other features.

Did you have Audyssey on? As you most likely know, if Audyssey is used, it would be resampled to 48 kHz regardless of the source contents. So in that sense, you can't lessen the effects of the slow roll off filter by much unless you don't use Audyssey. Good finding really, at least you have convinced me that Marantz made a bad choice on that filter as I do use Audyssey most of the time, even for music.

 

[viewcart]

It's the equivalent of the SR6014, and nearly identical components, but less expensive. It has 9 powered channels, but processing for 11 just like the other receivers. From what I hear, Auro is barely used on any movies so it's not important.

 

[bigguyca]

Such speculation sounded convincing, but apparently has just been shot down by Marantz themselves, perhaps inadvertently, now that we know the SR8015 is capable of near 100 dB SINAD too, whatever they might have done to the 2020 HDAMs. Last time they revised HDAMs was when they launched the AV8802A, SR7009 so that was about 6 years ago. Regardless, if distortion is so low, lower than 0.001% in total, then where are the magical warm sounding harmonics? Nothing apparent in the FFTs either if you compared models prior to 2020. In fact, if anything, the often referred to as warm sounding 2nd harmonics was a little higher in proportion as shown in Denon's FFT!!

Again, all that shouldn't matter at such low level of "total" harmonic distortions. And as I mentioned before, if they had found the HDAM magic, then why not include them n the slimline series? If cost is the reason, then they should have made it clear that the so called "better for music" deal would apply to the non slimline series only.. Bottom line, what they said in that video, if true, would defy logic..

Sound United SR8015 Measurements

There is no obvious indication of how Marantz made the measurements of the SR8015. It is also not clear if the measured unit is representative of production units. It is also not clear which channel was used for measurement. Based on the SR88012 the DA-height channels likely would provide the best measurements. Use of balanced AC power would also likely help reduce the noise levels . Based on the X6700H; don't trust and verify.

Unfortunately we will still likely be blessed with the non-standard reconstruction filter with no other choices.

Hopefully Marantz used the same measurement setup that Amir uses and the SR8015 will measure similarly when Amir has one inhouse. The ultimate Denon measurements have been good news. It would also be good news if the AV7706 shows better performance since it would provide a higher performing unit with balanced outputs.

HDAM's

The HDAM's in the AV8801, AV8802 and AV8805 are the same. The HDAM's in these units are four transistor circuits with two resistor current sources and +/-12V power supplies.

The preamp outputs of the various units are:

AV8801: opamp, HDAM, bi-polar transistor common emitter voltage gain stage, opamp, opamp. An additional opamp implements the other half of the XLR output.

AV8802(a) and AV8805: HDAM, common emitter voltage gain stage, HDAM. An addition circuit with HDAM, common emitter gain stage, HDAM, HDAM is used to implement the other half of the XLR output with what appears to be voltage and not current feedback.

Marantz has used higher performance HDAM's with transistor-based current sources in other products, but the lowest level HDAM circuits used in the AV880X series has not changed over the years.

HDAM circuits in the Marantz AVR's have been the same as in the AVP's for the SE output, except that +/- 7V power supplies have been used. These lower voltages in turn provide worse resistor-based current sources. The lower power supply voltage also doesn't allow headroom for the modest, first-order RC filter used in the AVP units The power supplies for the HDAM's are also less robust in these units.


Here is the (+) HDAM-based output stage of the AV8805 that was previously posted on AVS:

Note the four transistor HDAM circuit, then the two CE transistor stages and then another four transistor HDAM circuit. Resistors R4005, R4006. R4017 and 4018 are the resistor-based current sources.

Here are three alternative HDAM designs. The left design has transistor-based current sources, for example, Q5 plus associated diodes and a resistor form a current source. Naming of HDAM's is not consistent. At times the HDAM's in the AV-8805 have been called SA's. Clearly the HDAM's in the AV-8805 are not the same as the SA HDAM below.

 

[amirm]

Do we know if there are any 2020 Marantz's in queue to measure?

Some of the slim/low-end ones are offered for testing when they become available next month.

 

[Urgo]

Some of the slim/low-end ones are offered for testing when they become available next month.

We will have the opportunity to see how their Hdam really behave now.
I'm waiting to decide on my next receiver. Thanks for your job.

 

[Kanon]

One of the differences between this Marantz and the similar Denon is that Marantz has provision for 7.1 line inputs to all amps 'directly'. Making it essentially just a multichannel amp.

Any idea of performance in this mode? 2 channels? All channels driven?

Like Cahudson42 i am very curious about the measermants at the pre-out/speaker terminals when using the 7.1 analog channel input.
Amir, Is it possible for you to run these tests? I am using my marantz 7010 this way setting volume to 0,0dB, connected with the atom amp and using a topping 50s as dac.

 

[peng]

HDAM circuits in the Marantz AVR's have been the same as in the AVP's for the SE output, except that +/- 7V power supplies have been used. These lower voltages in turn provide worse resistor-based current sources. The lower power supply voltage also doesn't allow headroom for the modest, first-order RC filter used in the AVP units The power supplies for the HDAM's are also less robust in these units.


Here is the (+) HDAM-based output stage of the AV8805 that was previously posted on AVS:

Note the four transistor HDAM circuit, then the two CE transistor stages and then another four transistor HDAM circuit. Resistors R4005, R4006. R4017 and 4018 are the resistor-based current sources.
View attachment 80360

Here are three alternative HDAM designs. The left design has transistor-based current sources, for example, Q5 plus associated diodes and a resistor form a current source. Naming of HDAM's is not consistent. At times the HDAM's in the AV-8805 have been called SA's. Clearly the HDAM's in the AV-8805 are not the same as the SA HDAM below.


View attachment 80362

Again, things might have changed in the 2020 SR8015, not sure about if any such change would trickle down to the lower models.

Below is from Audioholics.com:

https://www.audioholics.com/av-receiver-reviews/marantz-8k-sr-series

"The new 2020 SR-Series AV receivers represent the next major step forward in home theater, not just for Marantz, but the entire home entertainment industry. Marantz fans will be some of the first to experience new levels of incredibly sharp image quality, remarkably fast gaming and immersive surround sound. But more importantly, superior Marantz HDAM-SA3 amplification based on decades of extensive tuning transports the listener ever closer to their music.
--Jake Mendel, global brand manager for Marantz."

I don't know if the information about the HDAM improvement for the SR8015 is accurate or not. Regardless, at least according to Gene's measurements, the SR8015's pre-out measured much better in THD+N at 2 V than the SR8012's; and that would bring it more in line with Denon's. That's potentially good news!