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Two questions about balanced operation ...

Two questions:

(1) I have a fully balanced preamp and CD player that I am running single-ended. I live on the 18th floor of an old building that does not have three-prong outlets. When I had dedicated lines for my amps installed, the electrician said that we do not have a water pipe that would be sufficient to run a ground wire to. Thus, the system is not grounded.

My question is, if I replace my single-ended interconnects with balanced interconnects, does the system need to be grounded in order for the balanced circuit to function properly? If the answer is yes, I'll stick with single-ended operation absent another solution or other information indicating that it is still better to run balanced, even lacking a ground, if your gear features a truly balanced circuit.

(2) I have read that an MC phono cartridge is a "naturally balanced device". Can someone explain this statement? (No need to address why this is or is not the case with MM cartridges unless you want to). A cartridge has a positive and negative connection for each channel, but no extra connections for a ground on each channel. The typical phono cable has a positive and negative lead for each channel, and a single ground wire for the both the arm and table (this is true whether the connection is a five-pin DIN or a pair of RCA's). So what's the scoop? Can a cartridge send a fully balanced signal through single-ended interconnects? I would think the answer is "of course not". Is it possible to use balanced cables from an MC cartridge to a balanced phono stage (I don't see how given the four-pin configuration of a cartridge's outputs).

In short, I would ideally like to take advantage of fully balanced operation for analog, but the cartridge's connections seem to say "single-ended only". Is it possible, practically speaking, to get a fully balanced signal from the cartridge to the phono preamp?

Thanks in advance for your responses.
raquel
6 responses Add your response
sfstereo
215 posts
 
Raquel,

Here's what I think:

1. balanced system work by canceling noise between + and - phase so not having earth should not reduce the effect.

2. I have not opened a MC coil but I view it as a transformer with the outputs being neither ground or positive. So the MC can be operated as single ended by grounding one side or balanced by floating both sides. A MC is naturally balanced.

The main purpose of earth ground is for shock safety.

Rich
metralla
945 posts
 
I'm not an expert here, so I'm just surmising. If the ground is floated on all components (as you have) and all equipment is connected together with balanced interconnects, won't all equipment then be at the same ground potential? From a safety viewpoint it is a concern that the relative ground has no path to earth, but the absence of a true ground should not affect the function of the balanced circuitry.

Regards,
prpixel
876 posts
 
Grounding and balanced interconnects are totally different things. Your comparing apples to oranges. Balanced interconnects have a positive, negative and ground wire. This allows for greater rf rejection/less noise. Single ended cables have only a positive and negative wire. Balanced IC's tend to be used more in the professional audio world and are better for long runs. many people here have reported a lower noise floor with balanced IC's. I use balanced from my cd to pre to amp. However, if your happy with your single ended cables then continue to use them.

I can't comment on question 2 because it's been far too long since I owned a TT.

Hope this helps,
jfrech's avatar
jfrech
1,816 posts
 
Regarding the cartridge and phono stage. Just because you run it balanced, doesn't equal better.

On my BAT VKp10SE, it has both single ended and balanced inputs, only balanced outputs. The XLR input is better, lower noise floor=more gain and detail.

However, I tried a Aesthetix Rhea, only has single ended inputs, and XLR/single outs. I ran it, single ended input, XLR outs. Wow. It's quite a phono stage. Bettered the fully balanced BAT VKp10SE in the same system. Mostly in the tightness and extension on the top and bottom end, and detail everywhere. The BAT held on strong in the mids and depth.

So moral of the story is, if you have XLR ins, use them. But don't make a purchase decision on it...
richm
7 posts
 
Everything here is partially correct.

If the ENTIRE SYSTEM is connected via balanced cables, you should not have balanced operation with no ground loop hum, though that's dependednt upon the engineering of each component.

A phono cartridge is a balanced source...all of 'em. Each channel has a + and -, so everything is there for balanced operation. Chances are your signal is being sent balanced to a phono stage that shorts the "-" signal to ground and converts it to unbalanced.
raquel OP
841 posts
 
Thanks to everyone for the responses.
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