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Can plainly see the fingerprints of 50 Hz AC mains in there. 100, 150, 200, 300 Hz... Such fixed frequencies are easier for the ear to pick out, even when visually obscured by broadband noise in such a plot.
Yes, but in the 8802 they are very low, rising not far above 120 dB.
 

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The noise is not amplified. Turning the 7702 volume as high as it will go does not increase the noise in my unit. It becomes a non-issue when listening to any source at normal volumes - unless you are OCD like I am and just know that it is present!
then it seems likely the noise is not produced by the audio circuitry but induced through some means.
 

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The Marantz outputs are:
a) XLR connectors
b) Balanced
c) Differentially balanced

All at the same time! :D

Don't let anyone tell you otherwise.
As per customer service response I just received, NOT differentially balanced:

Quote:

I apologize for the delay, due to the holidays it took a while to get the response. The outputs are balance, but not differentially balanced on the AV 7702.

Thank you
*****
Marantz Customer Service
 

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As per customer service response I just received, NOT differentially balanced:

Quote:

I apologize for the delay, due to the holidays it took a while to get the response. The outputs are balance, but not differentially balanced on the AV 7702.

Thank you
*****
Marantz Customer Service
Can someone provide a quick "Connectors for Dummies" summary. What is the difference between differentially balanced and just balanced, and why would it be important to us as owners?
 

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As per customer service response I just received, NOT differentially balanced:

Quote:

I apologize for the delay, due to the holidays it took a while to get the response. The outputs are balance, but not differentially balanced on the AV 7702.

Thank you
*****
Marantz Customer Service

Interesting, I wonder if the 8802 will be true differential, granted as long as you have a low impedance feed (600 ohm), 0 centered you should be pretty much OK.

I use Sunfire signature amps, via balanced XLR, and it's served me well, so I wonder how that amp is designed in comparison to the pre/pro. I have an Integra 80.6 at the moment, but am debating returning it and moving to the 8802 Marantz, just seems to be a nicer unit, granted a bit more costly..
 

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Roger, your comparing the 8801 to the 7702, I would think the 8802 from the earlier pics would have a lower noise floor. Granted at 102-105db down, you really shouldn't be able to hear it.

Everything is going to have some noise, if it's electronic, it will generate some level of noise..
 

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As per customer service response I just received, NOT differentially balanced:
Quote:
I apologize for the delay, due to the holidays it took a while to get the response. The outputs are balance, but not differentially balanced on the AV 7702.
Thank you
*****
Marantz Customer Service
Apparently their definition of "differentially balanced" is different than that in common use:

>>Signals are often transmitted over balanced connections using the differential modehttp://en.wikipedia.org/wiki/Differential_signalling, meaning the wires carry signals of opposite polarity to each other (for instance, in an XLR connectorhttp://en.wikipedia.org/wiki/XLR_connector, pin 2 carries the signal with normal polarity, and pin 3 carries an inverted version of the same signal).
 

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With single-ended amps, or low to moderate efficiency speakers, the Audyssey speaker gain calibrations will be in the "+" end of the range. The higher they are, the lower the noise at the speaker terminals.

With balanced connections (6 dB more drive to the amp), or high efficiency speakers, the speaker trims will be in the "-" end of the range. The lower they are, the higher the noise at the speaker terminals.
I had to read this a few times but I still interpret it as

- unbalanced output, noise reduces as speaker trim increases (i.e. more noise at -3 than +3)
- balanced output, noise increases as speaker trim reduces (i.e. more noise at +3 than -3)

is this what you meant? If so, can you expand on why this is? (as I don't get it so presumably I'm being dumb)
 

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Roger, your comparing the 8801 to the 7702, I would think the 8802 from the earlier pics would have a lower noise floor.
Very good point. Allow me to retract my post and await official specs from Marantz on the 8802. I did not see them at the website as yet.

Granted at 102-105db down, you really shouldn't be able to hear it. Everything is going to have some noise, if it's electronic, it will generate some level of noise..
Agreed. I think we have already seen that most AV7702 owners (including me) do not hear any noise under normal use conditions.:) If the 8802 is at all quieter, all the better.
 

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Apparently their definition of "differentially balanced" is different than that in common use:

>>Signals are often transmitted over balanced connections using the differential modehttp://en.wikipedia.org/wiki/Differential_signalling, meaning the wires carry signals of opposite polarity to each other (for instance, in an XLR connectorhttp://en.wikipedia.org/wiki/XLR_connector, pin 2 carries the signal with normal polarity, and pin 3 carries an inverted version of the same signal).
 

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As per customer service response I just received, NOT differentially balanced:



Quote:



I apologize for the delay, due to the holidays it took a while to get the response. The outputs are balance, but not differentially balanced on the AV 7702.



Thank you

*****

Marantz Customer Service

I'm not sure how customer service defines these terms, but the Marantz processors have balanced outputs that are by definition differential. The internal circuitry is single-ended, but the HDAM creates a balanced output via an inverter.
 

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I would think the two ways of doing this are two dedicated amp pathways (op amps, with one path inverted, and one normal. I suspect the easy and cheap way to do this, is to just take the final output signal, and feed it though a circuit to invert the output to the negative pin would be how most do it.



Really having the inverted signal and a low impedance (compared to the normal high impedance paths) are really what extends cable lengths and reduces noise in the pathways. Regardless of how you accomplish it, it requires some extra circuitry to accomplish it.



I just wonder if they handle it any different between the 7702 and the 8802 unit, as for sure the cost is much higher. I wish they would post up the full specs on the 8802 as they have with the 7702, but I haven't run across them yet..

From looking at the schematic for the AV7702 and published Marantz slides concerning the AV8802, it looks like the HDAM circuits in the two are identical. I don't know whether the parts vary, but I doubt it. The extra cost for the AV8802 comes from different DACs, different power supplies, different chassis, different boards for the DACs and HDAMs, and the like (and because they can).
 

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I had to read this a few times but I still interpret it as

- unbalanced output, noise reduces as speaker trim increases (i.e. more noise at -3 than +3)
- balanced output, noise increases as speaker trim reduces (i.e. more noise at +3 than -3)

is this what you meant? If so, can you expand on why this is? (as I don't get it so presumably I'm being dumb)
It's not all just a matter of which connector is used, but that adds to the equation since there's 6 dB more signal at the XLR outputs than the phono output. All else being equal (amp gain and speaker efficiency), that means one has to reduce the gain trims 6 dB for XLR compared to using the phono output.

Another way to look at it is to say the noise floor at the speaker terminals is 6 dB higher with the XLR. This assumes the noise in the phono output is mirrored in the XLR inverted output. We cannot know if that is the case as we do not know where the noise (hum/buzz in particular) is injected into the signal path. If the noise was uniformly added right at the output jacks, it would totally cancel via the XLRs! But that's not happening, as we're hearing the noise in the XLR outputs.

The only reason I mention the gain trims is not that the trims themselves affect the noise -- the output noise from the 7702 remains constant regardless of the gain trim settings. But in a system where we want to calibrate the volume control, we can trade off adding gain in the trims with applying attenuation in the amplifier (or the wire connected to the amplifier with a pad). The overall calibration remains the same either way, but the reduced amp gain reduces both the signal and the noise heard from the speaker. We can turn up the trims to get back to the desired signal level -- the noise floor stays put.
 
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Thanks for the response. FWIW the reason I commented is because I own a 7005 & swapping to the XLR outputs in my setup produced a pretty dramatic increase in noise. It was a while ago but I didn't understand why at the time so this might shed some light on it.
 

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Can someone provide a quick "Connectors for Dummies" summary. What is the difference between differentially balanced and just balanced, and why would it be important to us as owners?
Differentially balanced connection means that both signal paths carry the same audio (one is inverted from the other). A balanced connection does not require signals on both paths, only the impedance of the second path must be as identical as possible to the first path. This maintains the same CMRR of the interconnect as the differential connection, but loses 3 dB in S/N.

I have never seen plain "balanced, non-differential" connections in use. But if someone has a hum problem from a phono output driving a balanced input, it's possible to improve that with the correct resistor in the "- signal" ground path.
 

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Thanks for the response. FWIW the reason I commented is because I own a 7005 & swapping to the XLR outputs in my setup produced a pretty dramatic increase in noise. It was a while ago but I didn't understand why at the time so this might shed some light on it.
I should mention that when I say the XLR has 6 dB more signal than the phono, I am speaking about products like the AV7702, where the XLR uses the same signal as the phono output, and just adds an inverter. Many consumer audio products also do this, as it saves circuitry and works perfectly well.

But if you have some sort of product that aspires to pro XLR standards, the XLR output signal levels can be rather higher than consumer XLR jacks. That would further exacerbate the noise floor issue.
 

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A couple quick points on the past couple messages above. First, if you have a balanced amp, with XLR inputs, it's expecting to see the standard and inverted signals, so that extra voltage swing by having the inverted side is not all just pure gain in the signal pathway. As the normal and inverted signals will be used to cancel noise on the lines themselves, it will in theory be reduced back down at the amplifier. This is why the output of an XLR/Balanced output, and the requirement at the XLR/Balanced input will always be higher on both sides. As to create that negative swing, you will in effect double the voltage, and we should all know doubling the signal is 3db right there.

Also note from Roger's comment above, there is a difference impedance for standard phono inputs, and XLR inputs. I am not going to go dig right this moment, but if memory serves me correctly, on XLR it's 600 ohms, and on phono it's 10,000 ohms. This is a BIG difference, and just feeding an one leg of an XLR output, into a phono input will not work well, as you have a serious impedance mismatch. Can you do it, sure, but then you pick up all the noise, and probably tonal issues of having an impedance issue between the in and out of the devices. A phono out to an XLR in (single leg) should be a total disaster, as it's expecting the output stage to not only supply the correct voltage, but also the current that goes with the voltage, and that difference is large going from 10K ohm to only 600 ohm.

So in short, unless the designer of the unit designed the circuit to withstand the huge variation in impedance, you really need to keep like pathways the same, not mix and match from in to out, or as some have seen the end result will not really be pretty at all, especially if your trying to be a perfectionist..

Off my tech soap box for now.. :D
 

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But If the balanced and unbalanced output signals have the same SNR and the balanced signal is reduced by 6 dB at the amp input (say by using an XLR attenuator or amp input level control that doesn't add noise) then the noise should be no greater using the balanced connection.
 

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Apparently their definition of "differentially balanced" is different than that in common use:

>>Signals are often transmitted over balanced connections using the differential modehttp://en.wikipedia.org/wiki/Differential_signalling, meaning the wires carry signals of opposite polarity to each other (for instance, in an XLR connectorhttp://en.wikipedia.org/wiki/XLR_connector, pin 2 carries the signal with normal polarity, and pin 3 carries an inverted version of the same signal).
 

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Most home amplifiers with balanced inputs have high input impedance, as do most preamps with balanced inputs.
 
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