Marantz AV7005 Networking A/V Processor Review

[adk highlander]

Sorry, I have not been following this thread. I thought you were out of the woods.

Thanks I thought I was going to be clear as well. It is very disconcerting though that the new one is much much worse and not something I could live with.

Unless there has been a serious downgrade, I doubt those Marantz units are both faulty. The second might be, but I doubt the first is, unless there has been a serious lapse in standards, since my AV 8003. That unit has a superb massive power supply, and robust well thought out ground plane.

An internal ground loop is unlikely to result from a manufacture problem and would almost certainly have to be a design problem. So they would all be doing it, and I find it hard to believe Marantz would not know about it. You never know though in these days of the race to the bottom

You can tell if the Marantz has an internal ground loop. Listen via the headphone jack, with nothing else connected. If you here hum they are lousy units.

To make sure, make a lead up going xlr to in line phone socket. Unbalanced at the phone end. Connect to a pair of balanced outputs. That will drive any phones. See if you hear hum then. Him=lousy product. No hum, no internal ground loop.

I'll grab some cans from a friend and try them out. I must say that what I have now for noise is tolerable and you must get close to the speaker to hear it. If my Onkyo had not been so quiet I probably would be fine with where it is at.

Now you have a complex system and when you have that things can happen.

You should know it took a lot of work to quieten this system down.

I had a sub panel put in with a big ground to the main panel. I constructed a robust star cluster ground plane, grounding in all of the racks. I made sure all rack mounted units had good bonding to the racks, scraping paint where necessary. Check for good grounding with a meter.

Even after that, I had to redo Direct TVs work, and tie in the satellite system and the FM antenna.

Still there were big problems. There was definite RF interference from the Lutron Maestro light dimmers, of which there are a large number in this house.
This necessitated my redesigning the Luton Maestro dimmers. I have to say there engineers were highly cooperative. All production since then has this redesign. They still emit some RF. It is impossible to make an SCR dimmer that does not emit some RF and have a decent dimmer.

Still not there yet. I had to redo the whole house ground, and replace it with three seven foot copper rods tied together.

Still a problem. The phone ground was at the front of the house, a long way from the house ground. This was still causing a an earth loop. It was more than the 20 ft max, allowing me to tie it to the main house ground. So I gave the phone system its own 7 ft copper rod ground. This has still left me with a very slight ground loop, but you can only hear it with your ear right into a speaker driver. You can not hear it from any seated position. This will be eliminated in the next month or so, as Paul Bunyan telephone are constructing the first fiver optic PON pushed deep into a remote areas. The fiber cable, placed right by the main house ground will be hooked up as soon as the snow is gone. That will tie the phone ground to the main house ground. I expect that to rid my of the last vestige of hum.

One other issue is that my downstairs system, uses the FM and Direct TV connections. It is too far to tie the ground to the studio ground. You can not use ground isolators with Direct TV, because of phantom powering and signaling. So that whole system has to be totally disconnected from the house ground, and only grounds via the two Direct TV cables and the FM cable ground. Not the best situation, but there is no other way. If you ground it both system hum loud as you get a ground loop from the house ground and antenna cables.

So these situations are highly complex.

So I think you have a lot more work to do, before blaming it on Marantz, or changing units again.

I'm going to get my father out with some of his testing gear and see if he can help me diagnose the issue and at least figure out what may be causing the noise. Putting all the gear on one outlet/breaker did not make any difference. After my earlier PM's to you I redid all my interconnects and power wires to make sure they were away from each other and to cut out any possibility of that being the issue.

As always Dr. Marc you are a font of useful information and examples of real world fixes. Any outside work will have to wait a few months because like you I have a few feet of the white stuff on the ground.

I agree that I will not be changing units again as I don't want to waste my dealers time or his good graces.

 

[sterling shoote]

Why not both faulty? It appears, the problem with each is a different one. Proper analysis suggests an equipment problem, different for each.

 

[AcuDefTechGuy]

My 4308 (I know, not nearly as good as yours) is also quieter, I guess HTM's measurements does hold true in my case. In reality it really doesn't matter as a) I never listen at anywhere near 0, loudest I could tolerate is -10. At that level the Marantz is virtually silent.

I wonder if the hissing means anything significant?

Or is it just some insignificant line interference in the system?

Could it really be the SNR??? I mean it's not like the SNR is like -60dB or something. A SNR of > 90dB is nothing to be ashamed of.

I remember my Acurus preamp/amp and Emotiva MPS2 all had slight hissing sounds. They all had SNR > 95dB.

But they all sounded great.

 

[PENG]

I wonder if the hissing means anything significant?

Or is it just some insignificant line interference in the system?

Could it really be the SNR??? I mean it's not like the SNR is like -60dB or something. A SNR of > 90dB is nothing to be ashamed of.

I remember my Acurus preamp/amp and Emotiva MPS2 all had slight hissing sounds. They all had SNR > 95dB.

But they all sounded great.

No, it is only a touch louder than the Denon but 99.9999% of the population won't stick their one of their ear on the speaker grille where the tweeter is with the volume up to 0. Even then if you move your ear to about 8 to 10 inches away you won't hear anything. My Bryston does that too and it has SN through the roof. I have never been able to find an amp that is totally silent. The worst I have had heard in the past were some of those high end Anthem amps, Pioneer Elite AVR (older models). They all hiss and the Anthem had major transformer hum but that's quite a few years ago. Having said that, in every case I turned the volume up high and had my ear touching the amp for the transformer hum, and touching the speaker grille where the tweeter was. Don't ask me why I would do that kind of stupid thing, just ask yourself......

I am going to take more time to play with this pretty thing and will give you a mini review hopefully by Sunday.

 

[sterling shoote]

Gee, I must be one lucky dude. The only hum I've ever known was when I was sending analog from my Dell Inspiron 14 to analog in Sony TA-E9000ES. Eliminated this wall wart hum by going USB out to either S/PDIF or DAC.

 

[Cos]

I have just gone through 2 AV7005 units. Both had low level speaker hum and tweeter hiss. I have an AVM 30 and it works silently. I have reconfigured my home audio every which way and can not eliminate the hum or hiss. Granted 3ft away and I really can't hear it, but it is upsetting to spend $1500 on a unit that does this.

I have even had an electrician come out to my house to check for issues. I have tried different circuits. I rewired my speaker cable, still no success. I purchased an jensen isolater for my cable, but sound still occurs even when AV7005 is connected to my Anthem PVA7 via $600.00 worth of RCA cables and nothing else connected to it.

I am not sure what to do at this point.

 

[PENG]

I have just gone through 2 AV7005 units. Both had low level speaker hum and tweeter hiss. I have an AVM 30 and it works silently. I have reconfigured my home audio every which way and can not eliminate the hum or hiss. Granted 3ft away and I really can't hear it, but it is upsetting to spend $1500 on a unit that does this.

I have even had an electrician come out to my house to check for issues. I have tried different circuits. I rewired my speaker cable, still no success. I purchased an jensen isolater for my cable, but sound still occurs even when AV7005 is connected to my Anthem PVA7 via $600.00 worth of RCA cables and nothing else connected to it.

I am not sure what to do at this point.

Try a different amp, first connect very short cable a speaker and go from there. I heard hum from Anthem amps before too. No brands can guarantee 0 defects so there is always the possibilities that your unit is defective but it may be too early to confirm that yet.

 

[sterling shoote]

Here's what you do..send it back under warranty and ask for your money back. It's becoming clear here that this Marantz product is one to avoid. I've scratched it off from any consideration.

 

[TLS Guy]

Here's what you do..send it back under warranty and ask for your money back. It's becoming clear here that this Marantz product is one to avoid. I've scratched it off from any consideration.

Its not clear at all that the problem is with the Marantz. Interconnection and home electrical issues are far more likely with these types of problems.

 

[AcuDefTechGuy]

Here's what you do..send it back under warranty and ask for your money back.

LOL.

But I would have to agree personally.

If other pre-pro or AVRs don't cause the same issue under the same exact wires and condition, then I say there is something going on with the Marantz.

So if the OP swaps out the Marantz and hook up the other pre-pro or AVR, using the same exact wires, what will happen?

 

[AcuDefTechGuy]

I have just gone through 2 AV7005 units. Both had low level speaker hum and tweeter hiss. I have an AVM 30 and it works silently.

So the AVM 30 pre-pro works silently with the same exact cables/wires/outlet that were used for the AV7005?

Then I would return the AV7005 and buy something else, like the Anthem AVM 50v:

http://www.anthemav.com/products/anthem/a-v-processor/avm-50v-2

 

[TLS Guy]

LOL.

But I would have to agree personally.

If other pre-pro or AVRs don't cause the same issue under the same exact wires and condition, then I say there is something going on with the Marantz.

So if the OP swaps out the Marantz and hook up the other pre-pro or AVR, using the same exact wires, what will happen?

These issues are seldom the fault of the units. He has gone to a rack system.

When he first installed the Marantz the buzz was at a high level. My suggestions haveh got the noise already to where you can only hear it if you put your ear in a speaker. All it takes is a phone line not tied into the house ground, and the usual poor house ground to cause these issues. Those sort of issues are far more common and likely than internal ground loops in a device of that quality.

He did more than just swap units. He now has a rack, and it is easy to get ground loops with double insulated domestic gear with racks. The units must ground to the racks and it is really easy if you are not obsessional to get loops between the rack and cables.

The more complex the system, the more you run into ground loop issues.

You have to have a clear idea of your ground pathways on paper and in your head before construction. The you must verify with testing in the construction.

Where equipment does vary is in resistance to RF interference, from dimmers. It can be quite a job sometimes to distinguish ground loops from RF problems, as it sounds the same. My last Rotel unit was the devil for picking up RF. The new Marantz only picks it up very slightly. Unfortunately my Architect daughter filled this place full of SCR dimmers, so this house is about a worst case for that.

However I agree the dimmers are essential. That did create an interesting challenge though.

Unfortunately simple assumptions in this case have a poor chance of being correct.

 

[AcuDefTechGuy]

He did more than just swap units. He now has a rack...

What if he were to now simply swap out the Marantz and put back his Anthem AVM 30 under the same exact conditions?

If the AVM 30 has the same noise issues, then the Marantz is not at fault.

But if the AVM 30, under the same exact conditions, is 100% silent, then what?

 

[adk highlander]

What if he were to now simply swap out the Marantz and put back his Anthem AVM 30 under the same exact conditions?

If the AVM 30 has the same noise issues, then the Marantz is not at fault.

But if the AVM 30, under the same exact conditions, is 100% silent, then what?

TLSguy is referring to me not COS.

My dealer has offered to let me take home some receivers to try out just to see but after my conversations with TLS I'm thinking more and more it is something in my environment causing the issue.

 

[TLS Guy]

What if he were to now simply swap out the Marantz and put back his Anthem AVM 30 under the same exact conditions?

If the AVM 30 has the same noise issues, then the Marantz is not at fault.

But if the AVM 30, under the same exact conditions, is 100% silent, then what?

I wish it was that simple.

As I said, the biggest variation in units is resistance to RF. This is never tested in reviews, and nowhere does it appear in the specs. This is a big unrecognized problem, especially in HT.

Now grounding is a huge problem, especially when you have a rack.

The issue is that some units are double insulated and others three pin mains leads.

Now, you have a lot of options, once you mount a unit like the Marantz in question in a rack. It will ground the case to the rack. Now what do you do with other rack mounted units? They will ground through the rack. So what do you do with the mains lead ground, lift it or not? Usually trial and error here.

What about units not in the rack. Do you ground the chassis of those double insulated units to the rack or not? Then if you do, do you lift the mains grounds or not?

So whether a unit hums in a given situation depends to a very large degree on how the units ground plane is configured. And this leaves out house wiring and grounding issues, add them in and you have a real witches brew.

I found the house grounding, including antennas, TV feeds, and phone issues have to be considered in the whole design package.

So more likely than not, the Anthem would hum in some situations where the Marantz would not, and vice verse, without there being anything intrinsically wrong with either.

The issues really pile up when you have a big mix of pro and domestic gear, as I have.

One thing I can tell you for certain, if the unit in isolation does not hum at the outputs on the scope or through phones, then there is nothing wrong with the units ground plane. Then it is up to the user to figure out how best to install it. If he has hum after installation then the user or installer has to trouble shoot to get rid of it.

I was asked to visit a professional recording studio recently. There were boat loads of grounding issues unresolved. The studio like most was relying far too heavily on digital systems to remove earth loop generated hum. Lots of other issues as well, which I won't go into here. The studio was pretty much recording foul mouthed rappers from Atlanta for some reason. I guess it is called under ground rap. I declined to assist.

 

[AcuDefTechGuy]

My dealer has offered to let me take home some receivers to try out just to see but after my conversations with TLS I'm thinking more and more it is something in my environment causing the issue.

Then just try out those other receivers to confirm TLS Guy's PROVEN theory.

I think it will benefit other folks who have the same issues!

 

[TLS Guy]

Then just try out those other receivers to confirm TLS Guy's theory.

I think it will benefit other folks who have the same issues!

It's not theory, it's really learning about grounding issues, and experience learned in the world of hard knocks!

 

[AcuDefTechGuy]

It's not theory, it's really learning about grounding issues, and experience learned in the world of hard knocks!

Okay, I fixed it. PROVEN theory.

 

[Warpdrv]

Darn Shame that so many people are experiencing noise issues with this product....

AVS has a boatload of people as well...

Glad I didn't just jump on the bandwagon - I'll hold out for something else...

 

[PENG]

What if he were to now simply swap out the Marantz and put back his Anthem AVM 30 under the same exact conditions?

If the AVM 30 has the same noise issues, then the Marantz is not at fault.

But if the AVM 30, under the same exact conditions, is 100% silent, then what?

I am sure TLSG will take care of your question. Today I did an experiment on my rack that has the following hook up to one dedicated 20A and 1 dedicated 15A cct.

1 HDDVDP, 2 BDP, 1 PS3, 1 XDE500, 1 Denon DVD3910, 1 router, 1 switch, 1 PCUltra, 1 Adcom GFA555, 1 Marantz MM8003, 1 Marantz AV7005, 1 external computer cooling fan, 1 pair of rack lights, 1 Bell 6131 HD receiver. All powered by 1 dedicated 20A outlet and a 15A outlet.

1. With the GFA555 powering the L/R, the MM8003 powering the C, SL, SR, SBL, SBR, hum is only barely audible at 0 with ear within an inch or two from the mid bass driver and hiss barely audible at 0 also with ear within an inch or two from the tweeter. At -5, all is almost inaudible. This is for the L/R, the C seemed quiet.

2. Because the C was quiet so I reconnected the L/R speakers to the MM8003, now the hum is inaudible at 0 and seemed to be audible at +18 but I had to listen hard for it. The hiss was almost completely gone even at +18, certain silent at +5.

3. The SBL/R have virtually no hiss but always a hum that is audible only if my ears are within a couple of inches from them. The cables for the SB are about 35 to 40 feet long.

None of the above surprise me because as TLSG said, these double insulated stuff are not grounded so their each and every chassis are going to have their own and different potential and the so called ground loop (a misnomer as there is not real ground as such) currents are going to be there. So what happens then it that any hum you get will be dependent on the potential of the so called ground of each piece of equipment hooked up to the system. In my case, the two Marantz must have very similar ground (again not true grounds) potential, hence virtually no hum.

Hiss is a different story, it is more of an electromagnetically induced types of noise. How bad it can get will depend on many things, including the kind of wires (shielding), connectors, length, path, interference between wires, equipment that emit electromagnetic field, among others.

You can eliminate or at least minimize hums if you can equalize the potentials of all of your equipment chassis/frame ground and keep the speaker wires relatively short, but it would be hard to eliminate hiss completely if you have long runs of speaker wires. I would think that for most home systems, all these are moot point because such hum and hiss are only audible if your ears are part of your speaker's grille and when the volume is well beyond the level that you could tolerate. I have reason to believe only people such as you, TLSG, AK and I would bother trying to eliminate such low level noises. And I am guessing that most normal people won't even notice such noises. Me, I can tell you how each of my amps transformer sound and that's with nothing connected, just the hum of the transformer itself. I am sure you know the bigger the transformer, the louder it gets..