[STEF]

Hi guys,

You can see my question in the subject of this topic.

Regarding my experience (on my system), I prefer connect my 9SEV2 on the balanced input.

I don't know if there is a technical reason ? Answer from Nuforce team ?

Any others experiences.

Regards.

Stef

[bostonaudi]

The advantage is you have +6dB gain with true balanced, which puts the signal that much higher above the noise floor. Balanced circuits reason for being is to cancel noise, and this is important over long cable runs with sensitive signals, which is why professional cables are generally balanced.

[rustydoglim]

Agree with Bostonaudi.  If you have the preamp right next to the amp, then the advantage of the balance cable might be negligible.

[nuforce-casey]

Repeat one more time.....

Balanced offers no benefit as far as audiophile is concerned.   

In the professional world, XLR is used, because with many, many equipment hookeds up, XLR cables could prevent ground loop from happening.   XLR cable has separate negative signal and shield, and it helps avoid ground hum from occurring.

The reason that a long XLR cable is used to hooked up 2 pieces of equipment is because with the equipments separated, using RCA cable would have hum.  Why?   There is a big ground loop formed with the AC ground going on one hand, and the signal ground going on another hand, hence a huge loop. 



With XLR cable, the ground is broken between the 2 pieces of equipment, hence the hum is minimized.



When equipments are in close-proximity, the ground can be treated as a 'big one-point' ground.   In some rare cases where the AC sockets are not wired well, or the house maybe an apartment with higher ground potential, then each equipment could have a different AC ground potential - hence a current will flow from one equipment to another, inducing a hum on the RCA cable - because the negative return on the RCA cable is shared by signal and chassis ground.  On XLR cable, the shield connects the chassis together, therefore equalizing the chassis potential and kills the current flow.

[bostonaudi]

Repeat one more time.....

Balanced offers no benefit as far as audiophile is concerned.   

You mostly got this right, but the statement "Balanced offers no benefit as far as audiophile is concerned" is in my opinion flat out wrong, and your own reasoning helps to explain why. If the audiophile is keeping his/her equipment seperated (amp between speakers, preamp back along wall somewhere out of the noise/vibration path), runnning balanced, especially with a 5 or 6m cable run, can have audible benefits for all the reasons you stated - reduction of hum and noise, and the benefits of differential noise reduction. Pass Labs equipment for example, when connected fully balanced, is utterly transparent and noise free, even with 6m or more interconnects. I would agree that in a system with short cable runs, balanced isn't doing anything much for you and you likely won't hear any difference switching from balanced to single ended cables, other than the +6dB gain with balanced.

I would certainly not make the claim that balanced always sounds better than single ended either. Many companies derive a "balanced" input or output by just throwing a phase splitter onto the circuit board, which doesn't result in a truly balanced design, it only allows one to plug XLR's into the box (some companies save themselves the .30 or so on the phase splitter and just wire the XLR to the RCA internally, the "-" signal ends up doing nothing). In any case you have to listen for yourself. If I was making the decision to run balanced, it would be based on whether I needed to seperate my pre and power amp with a significant cable run, say 4m or more, and then I might consider going balanced.

While its from a company that only makes balanced equipment, and would have you believe balanced is the only way to go (so read with grain of salt) the following is still a good read on balanced:

http://www.balanced.com/faq/balanced.html

Also, read Pass Labs patents on super symmetry, very informative, as are all Nelson Pass's white papers on amplifier design.

Lastly, as stated, using XLR cables alone doesn't always reduce hum in a large sound system. Different chassis ground conditions even in a professional sound system with long cable runs can still cause hum issues (from experience setting up literally hundreds of band gigs).