• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Review and Measurements of Marantz AV8805 AV Processor

peng

Master Contributor
Forum Donor
Joined
May 12, 2019
Messages
5,614
Likes
5,167
The question I usually always ask is why anyone would use Direct/Pure direct though? This means no bass management, which means no subwoofers which means you could just as well buy a dedicated 2 channel preamp instead. Also you're missing out on room correction and so on. It is not worth the effort to try and run a Pure Direct setup with an AVR imo. Unless that is that you have an external crossover filter and doing a very advanced setup and need no room correction due to rebuilt room etc. But then again with kind of money buy a state of the art 2 channel preamp+DAC combo instead.

I have tried Pure Direct on a Marantz unit with surround during a demo scene with 10Hz content (this was years ago) without quite knowing what pure direct does. And at least in my unit the center channel 9" woofer was going crazy so for sure no bass management activated there. That was the last time using it. Imo at least no speaker is big enough to run full range. Always off-load to subs for less distorsion from speakers.

Agreed, aside from the use of subs and bass management, I can't hear a difference anyway. However, I would bet someone like RichB could, and unless we are there with him in a DBT session, we would have to take his word for it that he could in fact tell a difference. He can even hear a difference between his AHB2 and AT400NC (only iirc)
 

Kal Rubinson

Master Contributor
Industry Insider
Forum Donor
Joined
Mar 23, 2016
Messages
5,270
Likes
9,765
Location
NYC
The question I usually always ask is why anyone would use Direct/Pure direct though? This means no bass management, which means no subwoofers which means you could just as well buy a dedicated 2 channel preamp instead. Also you're missing out on room correction and so on. It is not worth the effort to try and run a Pure Direct setup with an AVR imo. Unless that is that you have an external crossover filter and doing a very advanced setup and need no room correction due to rebuilt room etc. But then again with kind of money buy a state of the art 2 channel preamp+DAC combo instead.
Yes, that's me. I am playing multichannel files from my NAS via a JRiver in my streamer and use a multichannel DAC as the output. All DSP and bass management is done in JRMC and I only use the Marantz for its volume control. Or course, I could use volume control in the DAC or streamer but it is more convenient to use the Marantz and its RC because we also use them for other sources (cable, B-D, Roku, etc.)

This setup sounds significantly better than the direct HDMI connection from streamer to Marantz and that is why my question about testing of the analog path on the Marantz is relevant.
 

RichB

Major Contributor
Forum Donor
Joined
May 24, 2019
Messages
1,946
Likes
2,611
Location
Massachusetts
It was quite clear that it would have to be in direct or pure direct mode and there would be no DSP, ADDAC in the path. I did PM the details at the time. The part that was not clear to me was, how then did it do the crossover thing. All he said was there was a tone control at the end of the volume IC.. I re-checked the block diagram and did not see the such tone control.

Yes, and bass management was a probable for A to D.

Emotiva documentation is quite clear:
- Reference Stereo is no DSP processing.
- Direct includes bass management but no REQ/PEQ, so DSP processing.

No discussion is needed about turning off the front display and video processing.

- Rich
 

bigguyca

Senior Member
Joined
Jul 6, 2019
Messages
477
Likes
617
I have followed this thread since its initial appearance and, just recently, needed to find out if you ever tested the signal transfer performance from one of the analog 7.1 inputs to either an RCA or XLR output. These are, as has been discussed, the only inputs that are subject neither to D/A nor A/D/A processes. Despite some effort, I cannot find this info. @amirm, can you comment?

Kal

To add to the above, further work using various measurements on the AVSForum in Denon/Marantz threads found that the RCA and XLR inputs do not go through the A/D/A process, that is, they are analog all the way in Direct and Pure Direct modes. JDSmoothie even gave up the A/D/A claim. The service manuals always indicated that this was possible and include tests of analog inputs without A/D/A conversions, but the service manuals didn't actually state that the product worked this way. The A/D/A claim was repeated so often that it was taken as fact. Such "facts" are all too common on the AVSForum.

One fact concerning the AV8805 is that the L and R inputs of all sorts, digital and analog, traverse two CMOS switches and the CMOS 8-channel volume control. It is likely that these two channels will measure worse vs. say C* or SR or SL channels, RCA or XLR. The CMOS switches and CMOS volume controls aren't too bad individually, but combined they offer worse performance than just the CMOS volume control.

Adding another 8-channel CMOS volume control and eliminating some of the RCA inputs, would eliminate much of this, but that's likely a couple extra dollars and private equity funds hate to reduce any cash flow, no matter how small. It's always sad when owners ask about running high performance standalone DAC's through AVR's/AVP's.


* The C analog input from the 7-channel inputs also goes through all these switches.
 

Kal Rubinson

Master Contributor
Industry Insider
Forum Donor
Joined
Mar 23, 2016
Messages
5,270
Likes
9,765
Location
NYC
One fact concerning the AV8805 is that the L and R inputs of all sorts, digital and analog, traverse two CMOS switches and the CMOS 8-channel volume control. It is likely that these two channels will measure worse vs. say C* or SR or SL channels, RCA or XLR. The CMOS switches and CMOS volume controls aren't too bad individually, but combined they offer worse performance than just the CMOS volume control.
OK but the big issue is that (1) they are not digitized (A/D) and, consequently, do not require conversion to analog (D/A) in the Marantz.
 

peng

Master Contributor
Forum Donor
Joined
May 12, 2019
Messages
5,614
Likes
5,167
Yes, and bass management was a probable for A to D.

Emotiva documentation is quite clear:
- Reference Stereo is no DSP processing.
- Direct includes bass management but no REQ/PEQ, so DSP processing.

No discussion is needed about turning off the front display and video processing.

- Rich

I believe direct/pure direct modes does result in the ADC/DAC path bypassed, the block diagrams clearly show how it could be done easily, and it could not have been a mistake because they were the same for every single Marantz and Denon AVP and AVRs that have the direct/pure direct modes and the NJU72750 switches and NJU72343 volume control chips.

If Marantz tech support has any doubt, I would give them the benefit of doubts that they would seek advice from their engineering team as they did for me the last time I asked them about the selection of the slow roll off filter.

Having said that, yes, like you, I was in fact disappointed and skeptical with his wish washy response to my question regarding bass management. On that, my logical thinking is that perhaps the selection of Stereo with Subwoofer on would automatically re-route the signal path to go through the ADC path. I suppose that's the "setting" that you alluded to, and that you and I have previously speculated on. My much older AVR-3805 was completely clear on this because it did not have the subwoofer on option in pure direct mode.

There is another part that drive me crazy, and I believe only @amirm can provide a probable answer to my question, that is:

In his measurements of the pre out on the AVR-X3600H using analog inputs he found no difference in SINAD whether direct/pure direct mode was on.

That is theoretically impossible because in stereo mode, the analog input signal has to go through the ADC path, so SINAD has to be limited by the AK5358BET that has the following specs:
https://www.digchip.com/datasheets/parts/datasheet/1608/AK5358BET-pdf.php

S/(N+D): 92dB, DR: 102dB, S/N: 102dB

In the analog input FR test Amir actually state: "Frequency response in all three modes was wide showing no digitization at low sample rate...", how was that even possible? In stereo mode, it has to go through the ADC, the AK5358BET!! So how was it possible that this thing measured significantly better on Amir's bench in "stereo mode".

So unless D+M has a hidden feature, as I/we speculated on the possibility of triggering the ADC bypass based on the subwoofer and modes (stereo, direct/pure direct) combined selection. If that is true, that I would say hats off to them for such an intelligent hidden feature.

@amirm , please share your thoughts on this. I am now so curious to the point I want to try giving Marantz or Denon a call tomorrow about this simple question that so far has been answered by their tech support, yet we are still doubting their answer only because of bass management, especially RichB and bigguyca.
 

peng

Master Contributor
Forum Donor
Joined
May 12, 2019
Messages
5,614
Likes
5,167
OK but the big issue is that (1) they are not digitized (A/D) and, consequently, do not require conversion to analog (D/A) in the Marantz.

That is my belief, derived from the service manual's block diagrams and confirmed by D+M support, but doubted by RichB and I because of our questions on the availability of some basic bass management even in pure direct mode except when the MCH analogs are used.

To me, it seems that the only logical explanation is that D+M has a hidden feature, that the software/firmware has a smart, such that regardless of the 3 modes (stereo, direct, pure direct), if the subwoofer is "On", the analog signal path will be routed through the ADC, if not, then in direct or pure direct mode, it will be routed directly to the volume IC, that is, bypassing the ADC path. So to summarize:

Stereo mode - signals from analog inputs will be routed to the ADC, then DAC, but it may (as indicated in Amir's measurements) still bypass the ADC if subwoofers are selected to "none". I speculate this part only because of the ASR measurements, that clearly exceed the ADC chip's specs, only Amir can confirm is he in fact has measured in Stereo mode with no subwoofer (selected none...?)

Direct/Pure direct - signal from analog inputs would be routed directly to the volume IC, but would revert back to the ADC/DAC path if the subwoofer output is selected to be "On" and bass management is used.

Again, above is just my speculation. Marantz response is simply:

"Looking at the Analog Audio Block in the 7705's service manual it appears that an analog input signal while in Direct or Pure Direct mode does bypass the DSP and there's no ADC/DAC at that point. The signal is sent to 2 independent switches, then to the volum eIC and finally to the HDAM module before it goes to the pre-out section."

For your AV8805, even if you use the MCH analog inputs I highly doubt you would do any better in terms of SINAD because the AK4490 DAC and volume IC are not the bottle neck as Dr. Rich of hometheaterhifi.com alluded to. One logical explanation for the good but not too impressive SINAD measurements could be (and Dr. Rich did gently hinted) that the HDAM might have been the contributor. To me, that is highly likely to be the case, it would be very difficult for a discrete buffer circuit with no fewer that 10 transistors on board, for each channel at such price point to out perform a reasonably well design volume IC such as the NJU72343. To me, the HDAM implementation may make sense in their integrated amps, but in the last stage of the preamp as implemented in the AV8805, 8802 and their AVRs, it has to be for marketing reasons only. Their design team must know that while such an extra discrete circuit based buffer cannot turn the tide at the end stage if its own distortions+noise could only be added to the hardware such as the DAC and vol IC preceded it. That's just simple logic. It likely would help maintaining SINAD at higher output levels, depending on the input impedance of the matching power amps, while again, adding THD+N of its own, however minute the effect may be.

Purely based on logic, in terms of SINAD for RCA output up to around 2.5 to 3V, that is 6 V for XLR, I would boldly predict the Denon AVR-X8500H is actually the best AVP in the D+M line up, not the real AVP, the AV8805. That's because for all intents and purposes, aside from the XLR connections, the signal paths of the two are technically the same, but the Denon will not have the extra THD+N introduced by the HDAM.
 
Last edited:

digicidal

Major Contributor
Joined
Jul 6, 2019
Messages
1,981
Likes
4,838
Location
Sin City, NV

That has to be the most confusing value proposition I've ever seen. Even if there is some nominal increase in performance (unlikely) or decrease in noise/distortion (a bit more likely, but unproven) - the primary bottlenecks remain completely unchanged in this process. The quality and values of the caps and opamps is not the "achilles heel" of these processors.

Paying nearly 100% of MSRP a second time to gain a nominal (potential at best) benefit when simply paying ~7000€ in the first place for a better performing processor seems a much better value. Especially considering you're then likely getting a processor with Dirac and full 16 channel output and the very latest codecs and better DAC/ADC.

Oh and you void your warranty and dimish your resale further in the process... sign me up! :rolleyes:
 

audioBliss

Active Member
Joined
May 7, 2019
Messages
258
Likes
294
Location
Sweden
I've heard of similar companies (or maybe it's the same one) that modifies high end home theater gear and makes it measurably better by quite a lot. But very, very expensive and as we all know players, AVRs and other front end electronics get outdated quite fast.
 

digicidal

Major Contributor
Joined
Jul 6, 2019
Messages
1,981
Likes
4,838
Location
Sin City, NV
I've also read about similar offerings - in every case with a profound dearth of measurements to back up any of the claims. It begs the question whether they lack the instrumentation to adequately document the "problem" - in which case how did they solve it? More to the point, how did they verify that their solution didn't actually exacerbate it?

Ironically, I would be far less opposed to such a pricey modification if it were being performed on a 20-30 year old preamp (and designed more to get another 20 years out of it, rather than 'supercharge it'). That would make much more sense to me - both because the device is certainly better built, and because 2ch playback doesn't undergo the same built-in obsolesence cycle that a prepro/DSP does.
 

Frank Dernie

Master Contributor
Forum Donor
Joined
Mar 24, 2016
Messages
6,445
Likes
15,778
Location
Oxfordshire
I've also read about similar offerings - in every case with a profound dearth of measurements to back up any of the claims. It begs the question whether they lack the instrumentation to adequately document the "problem" - in which case how did they solve it? More to the point, how did they verify that their solution didn't actually exacerbate it?

Ironically, I would be far less opposed to such a pricey modification if it were being performed on a 20-30 year old preamp (and designed more to get another 20 years out of it, rather than 'supercharge it'). That would make much more sense to me - both because the device is certainly better built, and because 2ch playback doesn't undergo the same built-in obsolesence cycle that a prepro/DSP does.
There have been people making mods to electronics for years.
One of my friends services and repairs, mainly old, valve amplifiers.
He had a popular old amp in for service which had been "improved" by a very well known guru here in the UK.
The mods were very extensive and used expensive parts but the distortion was more than a standard amp (he has had dozens through his repair shop) and maximum power was reduced to 4 watts before even more distortion set in.
It certainly sounded different but was much worse performing. The owner loved it.
 

P_M

Active Member
Joined
May 31, 2019
Messages
131
Likes
51
Location
San Francisco Bay Area, CA
I think the target of this idea are consumers who may be in the market to buy a new avr. They can either spend on a brand new avr or spend about the same on rebuilding the one they have.

if there was a service to do at least the most impactful mods at half the original price of the unit, I'd be interested in getting it done on my amp/avr.
 

Sal1950

Grand Contributor
The Chicago Crusher
Forum Donor
Joined
Mar 1, 2016
Messages
14,068
Likes
16,597
Location
Central Fl

tripitz

Member
Forum Donor
Joined
Aug 12, 2020
Messages
37
Likes
21
Is there any confidence that the McIntosh implementation is an improvement over the 8805 that it is based on, particularly with 2 channel audio? I believe I saw pictures showing an identical HDMI board and changes throughout the rest of the unit, including a few of the other boards.
 

witchdoctor

Active Member
Joined
Oct 6, 2019
Messages
232
Likes
125
I am buying a new unit based on the features as suggested and am comparing the 8805 with Anthem's new AVM 70. One feature the Marantz has is XLR in. Can anyone comment on this feature? Anthem includes XLR inputs on its stereo preamp but excludes them in their processors. If XLR aren't important why include them on their stereo pre but not on their HT pre?
 

Kal Rubinson

Master Contributor
Industry Insider
Forum Donor
Joined
Mar 23, 2016
Messages
5,270
Likes
9,765
Location
NYC
I am buying a new unit based on the features as suggested and am comparing the 8805 with Anthem's new AVM 70. One feature the Marantz has is XLR in. Can anyone comment on this feature? Anthem includes XLR inputs on its stereo preamp but excludes them in their processors. If XLR aren't important why include them on their stereo pre but not on their HT pre?
Two different markets. XLRs are rare in the AVR/AVP area as most of the emphasis is on digital sources. XLR inputs in the stereo preamp area are an up-market feature.
 
Top Bottom