RCA or XLR from PRE/CD/AMP

[SoundEngine355]

What do you use between your Classe PRE/CD/AMP RCA or XLR?

My distance from the CD to AMP is only 1m, so I am tempted to use RCA, however I have heard XLR can give 2-3db more output.

[htsteve]

I do not have Classe (I have Mac), but I use XLR between pre and amp. I found them to be quieter than the RCA's.

[ChrisssB]

Currently I use XLR but I'm tempting to go back to RCA...( DAC to pre)
I find XLR is quiter but I think there's more "bloom" and immediacy when I use RCA.
I don't know why, maybe Benchmark isnt a true Balanced design or this is the result of cardas GR...

[Srrndhound]

I'm using 12' RCAs from the SSP-800 to the Classe amps. No noise problems at all. I like the purity of single-ended circuitry.

[mjb]

Use XLRs if both ends are balanced (3 conductor) as its the better system, although on short cable lengths (< 2-3 meters) it honestly won't make too much difference.

[Kal Rubinson]

What do you use between your Classe PRE/CD/AMP RCA or XLR?

Whatever. Although there are specific exceptions, there are no consistent and general preferences for sound quality. The major advantages of XLR are the more positively-latching connectors and the potential for less noise with really long cables in RF-noisy environments. The major advantage of RCA is cost. FWIW, I run 10meter interconnects.

My distance from the CD to AMP is only 1m, so I am tempted to use RCA, however I have heard XLR can give 2-3db more output.

So what? Does your system lack for LOUD?

Kal

[Orb]

I find it interesting where some manufacturers costs are so much higher for XLR compared to RCA, while others are just a little more expensive.

As an example I noticed that comparing say Chord Company Chorus 2 to say Nordost Heimdall, the Heimdall seems more of a bargain as XLR while Chorus 2 is much cheaper as RCA.

Isnt there also another benefit of XLR that it can reduce hum due to earth related differences between units?

Cheers
Orbs

[Kal Rubinson]

Isnt there also another benefit of XLR that it can reduce hum due to earth related differences between units?

Cheers
Orbs

That's possible but it is a band-aid for a problem that should be solved more properly.

[sikoniko]

Now, my reply will be non-technical in nature, and would probably need to be translated, but it is my understanding that both classe amps and the ssp-800 are natively wired in balanced. to input SE means there is a translation.

I believe someone else on this board found that if you are not using balanced interconnects, you cannot use bypass mode for an external source. I've not tested this because I use XLR's so I'm unsure if that is fact or fiction.

[Blue-Eyes]

I use XLR between the CD player / SSP and XLR between the SSP and the AMP.

Another reason is the XLR bypass when playing CD's.


Btw: its 6 DB, nog 2 or 3 DB louder

[style]

Hi,

I'm pro XLR not "only" for the 3 DB....I have too my cd - pre -amp in max 1,5 meter. but fur the MORE CLEAN signal, no noise,.....


XLR :T

Style

[Srrndhound]

Btw: its 6 DB, nog 2 or 3 DB louder

Yes, the signal is 6 dB higher, and the noise is 3 dB higher, for a net S/N improvement of 3 dB.

The major advantages of XLR are the more positively-latching connectors and the potential for less noise with really long cables in RF-noisy environments.

I’d say the major benefit of balanced inputs is not RF rejection, but AC hum rejection. The common mode rejection of active differential inputs (as we are discussing here) is not nearly as good as with input transformers (i.e., Jensen), but no matter. Both unbalanced and balanced inputs (properly designed) have sufficient RF immunity anyway as a result of limiting their bandwidth to audio/ultrasonic range.

Now, my reply will be non-technical in nature, and would probably need to be translated, but it is my understanding that both classe amps and the ssp-800 are natively wired in balanced. to input SE means there is a translation.

While the Classe amps offer balanced inputs, they are not natively balanced in the amplification stage. If they were, there would be a signal on both output terminals, in opposite polarities. That does not happen whether you drive it from RCA or XLR, so there must be some translation from XLR to single-ended inside the amp. Quite normal. Perfectly acceptable.

The SSP-800 does reportedly have differential DACs, so I’d presume they maintain that thru the volume control to the preamp outputs. If you use them, you get the 3 dB S/N benefit over the single-ended connection. Aside from that, there’s nothing about such a design that limits its performance for single-ended outputs. It performs both to their fullest extent.

[Kal Rubinson]

I’d say the major benefit of balanced inputs is not RF rejection, but AC hum rejection. The common mode rejection of active differential inputs (as we are discussing here) is not nearly as good as with input transformers (i.e., Jensen), but no matter. Both unbalanced and balanced inputs (properly designed) have sufficient RF immunity anyway as a result of limiting their bandwidth to audio/ultrasonic range.

True but only if there is a hum problem due to grounding. As with any noise rejection mechanism, including good input transformers, its value depends on the existence of the problem needing a cure.

Kal

[Srrndhound]

True but only if there is a hum problem due to grounding. As with any noise rejection mechanism, including good input transformers, its value depends on the existence of the problem needing a cure.

I need to clarify what I was trying to say. ops:

I was trying to say that the common mode rejection of active differential inputs is perfectly adequate and useful at low frequencies like AC hum and its harmonics, but at very high frequencies, and certainly RF qualifies there, the rejection is essentially nil, since those circuits do not operate at such frequencies, let alone remain well balanced. Transformers, OTOH, maintain good common mode rejection over a much wider bandwidth.

Balanced inputs are beneficial for both grounding problems as well as for eliminating hum induced in interconnects in systems with no grounding problems. I agree that preventative means would be the better solution for either case.

[Kal Rubinson]

I need to clarify what I was trying to say. ops:

I was trying to say that the common mode rejection of active differential inputs is perfectly adequate and useful at low frequencies like AC hum and its harmonics, but at very high frequencies, and certainly RF qualifies there, the rejection is essentially nil, since those circuits do not operate at such frequencies, let alone remain well balanced. Transformers, OTOH, maintain good common mode rejection over a much wider bandwidth.

Balanced inputs are beneficial for both grounding problems as well as for eliminating hum induced in interconnects in systems with no grounding problems. I agree that preventative means would be the better solution for either case.

OK. I fully concur.

Kal

[Glen B]

While the Classe amps offer balanced inputs, they are not natively balanced in the amplification stage. If they were, there would be a signal on both output terminals, in opposite polarities. That does not happen whether you drive it from RCA or XLR, so there must be some translation from XLR to single-ended inside the amp.

The Classé amps are similar to the old Mark Levinson No. 23.5 and No. 27.5, where the XLR input signals were differential up to the current mirror stage, although Classé notes in their specifications that the amps are "fully differential from input to output." The CA-M400 and Omegas are supposed to be full differential.