Balanced vs. Unbalanced - What does it mean?

I'm not sure if this has already been noted here, but I'd like to clarify: You cannot be sure that an unbalanced output can be effectively run into a balanced XLR input merely by the simple addition of a physical adaptor. ARC gear will not work correctly in this set-up. That is why ARC sold their transformer.

IIRC, ARC's power amp protection circuitry will be triggered by the unbalanced input signal and severely limit the amp's power output. This is evidently a function of the protection scheme that ARC uses in its power amps. Other brands may (or may not) have similar problems. Probably best to check with the manufacturer.

Good Luck.

Marty

Then, the next step is to determine what sounds best *to the listener*. In the end, that's all that matters.

I think we all agree on this but "try 'em out and see" is not helping to increase understanding. (I am sure that Cam will take this for granted - I am sure he is going to listen and see)

However, a listen and see kind of approach is exactly how sonic properties become associated with interconnecting wires when the root cause is equipment related or impedance matching or mistaken volume level matching or any of hundreds of possibilities that have nothing to do with the purity of the copper. Creating a new myth every month, week or day.

Sometimes (perhaps often) degradation to a musical source is not always inherently obvious to even a trained listener (small amounts of compression and distortion can even regarded perceptively as pleasant or an improvement). This is why there are companies like Audio Precision otherwise we could ALL, as an entire industry, simply "try 'em out and see". Sadly "try 'em out and see" is the only approach that some manufacturers actually practice. This is how you end up with nice sounding products that do not reproduce the source material with much accuracy (measure badly but are claimed to be SOTA).

Bob Reynolds: It may not have been clear from the other posts, but there is zero advantage (other than the XLR being a better connector) of connecting the unbalanced signal from your preamp to the balanced input of your amp; there will be no noise rejection.

TVAD: IMO, there's zero benefit connecting single ended outputs (Linn) to balanced inputs (MC402). Might as well run single ended. But, try it both ways and decide for yourself.

In principle, I don't think that is true, gentlemen, although of course in practice whether it would yield a net improvement, a net degradation, or no net change is dependent on the specific equipment and the specific noise environment.

See Figure 2.1 of the Jensen paper I linked to earlier, and the words immediately under the figure:

http://www.jensen-transformers.com/an/an003.pdf

Note the statement that in this example CMRR will be "only 30db at 60Hz." However, 30db rejection of common mode noise (at least at the power line frequency) is considerably better than no noise rejection.

Basically, by using the adapter cable into a balanced input you are still driving a balanced differential input stage with a cable whose construction provides symmetry between the hot and cold signal lines. Therefore noise pickup in the cable will tend to be closer to equal between those two lines than between the shield and the center conductor of an unbalanced interconnect, allowing the differential input to still subtract out that fraction of the noise which is picked up symmetrically.

And note in Figure 2.1 that currents flowing in the shield of the interconnect due to voltage differentials between the chassis of the two components (caused by offsets in their ac safety grounds) will not be sensed by the differential receiver stage, while they definitely would be by a single-ended input stage.

Shadorne: However, a listen and see kind of approach is exactly how sonic properties become associated with interconnecting wires when the root cause is equipment related or impedance matching or mistaken volume level matching or any of hundreds of possibilities that have nothing to do with the purity of the copper. Creating a new myth every month, week or day.

Very well put! And I'll add that both the op and Mechans specifically seemed to be asking for technical explanations, which I think have now been provided and which, while obviously not being the final determinant of what is best in any given system, can help prevent going down the wrong path and even blowing up equipment (as cautioned against in my second prior post).

Regards,
-- Al