Balanced vs RCA between amp/preamp

Regarding ground connection being connected first and disconnected last  IS true if one wire the balanced connections as perhaps intended. The shell which has the 4th terminal on a 3 prong XLR connector is intended for Chassis ground.  XLR connectors are available with up to 6 (7) termination points.  

Most however don't use this 4th connection point, including me.  Pin 1 Chassis Ground, Pin2 Positive Node Pin3 Negative node.  So to refer to the OP since your Marantz gear have the same termination on both pre and power amp - your in electrical phase and don't need to do anything else.

As far as balanced operation which in my opinion offer vastly improved performance dynamics for an example and noise rejection and that the interactions of the cable is practically eliminated the list goes on.  All the equipment we make is fully balanced form input to output. Even on our economy line Liberty Audio the gear is fully balanced.

Good Listening

Peter

https://pbnaudio.com

Thanks for your input, Peter (Pbnaudio). Yes, depending on the specific designs what could be connected first and disconnected last when XLR cables are connected and disconnected may be either chassis ground or circuit ground. As you are doing in your designs and as explained in this Rane application note, connection of pin 1 to chassis ground in both components is proper practice (although unfortunately far from universal practice), with connection of chassis to the shell being optional.

On another note, regarding whether or not the OP’s specific components are fully balanced and whether or not they use inexpensive op amps to generate or receive one or both signals in the balanced signal pairs, I see that service manuals for these components, presumably including schematics, can be downloaded at hifiengine.com if one is registered there. I’ll try to take a look at them tomorrow, as that site imposes a limit of three downloads per day and I’ve already reached that limit today.

Best regards,
-- Al

I own balanced equipment, before I had SS unbalanced amps, on my rig and judging with my ears and a professional pianist ears as well I have replaced the balanced cables with mogami 2534 shielded, mogami 2549 unshielded, wireworld eclipse and in all three instances we weren't able to notice any difference in sound. Additionally to all these, replacing other components like dac, USB cables etc. Haven't made too much of a difference, as a matter of fact there have been a small difference in instrument presentation and Soundstage when changing things at the source but almost not noticeable not like others report on similar rigs with unbalanced connextions. Some people have recommended not using balanced shielded cables as they state sounds worse, I don't doubt it I just can't tell the difference on my rig.

My point is I truly suspect by empirical experience that balanced well designed equipment could be impervious, or maybe I should say apparently more resistant to changes on interconnects. 

Just my thoughts, 

Oh one more thing, there is unbalanced only equipment that price wise I seen it to be more expensive that their balanced counterpart, it might not be a general rule but it happens so cost IME is not so much of an issue. 

So back at wec56, yes using balanced vs unbalance there could be a difference IMO. You should experience more of a difference using different equipment manufacturers than cables anyways. 

Enjoy your system 

Reading the initial post again I missed something, the input source is single ended, this is a question for the others answering in this thread as I'm not sure of the answer. When the source is single ended shouldn't be the output single ended as well even when using the XLR output? 

As promised, I have downloaded and examined schematics for the OP’s preamp and amp, which as I had mentioned in my previous post can be obtained at hifiengine.com if one is registered there.

The amp is not fully balanced. However, while the circuit configurations used to receive balanced and unbalanced inputs are of course somewhat different, both inputs are processed through circuitry described as follows:

HDAM SA3

Marantz developed its own discrete circuit boards to replace standard IC's. These HDAM's consists of discrete surface mount components with short mirror image L/R signal paths. Those devices are doing exactly the same thing as the Op-Amps, but outperform the regular IC Op-amps dramatically in terms of the Slew Rate and reduced noise level, resulting in a much more dynamic, accurate and detailed sound. Over the years Marantz developed different types of the HDAM to improve quality and to fit to the special requirements of a product category like CD or amplifier.

Two HDAM SA3's are in the path through which each balanced input is processed; one of those two is in the path through which each unbalanced input is processed.

The preamp is also not fully balanced. However, a good deal of the circuitry which precedes its balanced outputs is symmetrical and is therefore balanced, although not differentially (i.e., it does not utilize differential stages). That circuitry also utilizes the HDAM SA3, followed by a number of stages utilizing discrete transistors.

Given all of that, my guess in this specific case is that it is more likely than not that a balanced interconnection will be preferable to an unbalanced one.

Luisma31 8-4-2019

Reading the initial post again I missed something, the input source is single ended, this is a question for the others answering in this thread as I'm not sure of the answer. When the source is single ended shouldn't be the output single ended as well even when using the XLR output?

While I suppose there may be a few exceptions, usually a preamp which provides balanced outputs when it is provided with balanced inputs will also provide balanced outputs when it is provided with unbalanced inputs. And examination of the schematic for the OP’s preamp confirms that is the case here.

Best regards,

--Al