Topic: Neumann LC3 question

[Teen Wolf Blitzer]

Can these be hacked and made out of silver cable?  I'm sure the cable is already nice quality but thought it was worth asking.  Thoughts?

[Lil Kim Jong-Il]

It would have to be thin cable but I'm sure you could do it.   I had an intermittent fault in one conductor of my LC3.  I sent it in and neumann shortened it to eliminate the bad section.  Seems clear to me that the ends are designed to be serviced.  The only issue I would expect is that the teflon stuff is very stiff.  I bet that belden would be nice.

[Teen Wolf Blitzer]

Hmmm     Wonder what kind of cable it is stock.  I'm sure it more than decent though. Wonder if Nick would do this for me.  Oh Nick.... 

Oh ya do most 140 folks run the bodies out of the deck?  I don't think I wanna do this for space reasons.  Was thinking shorty silvers.

[Shawn]

Hmmm     Wonder what kind of cable it is stock.  I'm sure it more than decent though. Wonder if Nick would do this for me.  Oh Nick.... 

Oh ya do most 140 folks run the bodies out of the deck?  I don't think I wanna do this for space reasons.  Was thinking shorty silvers.

I do.

[Lil Kim Jong-Il]

I have run the bodies out the side of my 722 for a couple of occastions but usually I run shorty silvers between the bodies and the deck.   I like to mount the bodies so that the lemo socket is facing up (I have the old style LC3s).


I have some issue with one body not liking to catch in the panel mount connectors but never has a problem with the cable end connectors.

[it-goes-to-eleven]

I've thought about replacing my kc5 cable with 1804a..

The cable between the cap and the body is unbalanced... So you want a very high quality shield.  The shield coverage on 1804a is pretty pathetic (78%).  The Schoeps KC5 active cable, for example, has much heavier shielding than any other mic cable I've seen and is night and day vs. 1804a.

Also, 1804a was designed as a balanced microphone cable. The kc5 cable was designed as an unbalanced active microphone cable.  Completely different intended use.

The kc5 cable was engineered specifically for the intended use and the guys who eval those cables have made their living evaluating sound for decades.  It is unlikely that an ad-hoc subtitution would equal what they've had specifically made for the application. I suspect the same applies to the Neumann cable.

Schoeps makes active cable in a few different diameters. The big stuff on the kc5's is kinda heavy. The cable used on the CCM's is lighter (though is only 2 conductor vs. 3). I'm not sure how many conductors Neumann uses.

[Steve J]

Oh ya do most 140 folks run the bodies out of the deck?  I don't think I wanna do this for space reasons.  Was thinking shorty silvers.

I don't run the bodies directly into the deck / preamp for a couple reasons. One, as you've noted, is the space consideration: either there's just not enough clearance around the deck to do it or the tolerance of the jacks themselves makes it difficult to plug the bodies directly into the deck / preamp.

Then there is my "clumsy factor": the bodies are a fairly sturdy piece; and if they're sticking directly out of the jack, there is no stress relief should they get jostled. I'd be concerned that jacks might get damaged if something or some one banged into the bodies.

[fozzy]

Schoeps makes active cable in a few different diameters. The big stuff on the kc5's is kinda heavy. The cable used on the CCM's is lighter (though is only 2 conductor vs. 3). I'm not sure how many conductors Neumann uses.

Isn't the cable for the CCM is just basically a balanced mic cable, is there anything going on in the XLR housing itself?

Can you buy the raw cable that is used in the KCx cables?

[Evil Taper]

XLR cables are always balanced (+ - G) via the 3 pins.  Since the cable is unbalanced it's actually operating at a different impedance than a standard XLR (-10dB unbalanced instead of +4dB balanced).  Unbalanced cables only have a +hot and -hot, no ground, which means that RF noise, cycle hums and ground loops are not eliminated resulting in noisy signal.  That's just some extreme basics on cables.

But now on to the issue, I'm NOT FAMILIAR with the circuitry of the Neumann system because I've never seen a schematic or signal flow diagram of the system itself.  The fact that the cable itself is unbalanced doesn't matter if there is a balancing transformer between the cable and the final output of the signal.  If the final output from the mic is a standard mic level signal and not overly quiet (14dB quieter aka nearly 5 times quieter) than you can bet the signal is being balanced somewhere in the path.  An unbalanced output would be very quiet and noisy (the same as an instrument output without preamplification) so I'm willing to bet that the system was designed to balance itself.  HOWEVER, if the output is unbalanced you can just buy a direct box or line isolator to balance the cable which will output a clean and balanced signal.

Could you replace the stock wire with silver wire?  Yes.  You would need to reverse engineer the cable and build a replacement with the wire of your choice.  The active cables have a different number of conductors than standard mic cable so you would need to have someone construct an identical cable with the silver wire.  Someone who really knows that they're doing would be able to do this but the labor involved would make is more expensive than it would be worth.  The results would be theoretically more pristine, due to silvers higher conduction efficiency, but since the cable itself is only passing signal from the capsule to the body without involving any circuitry or processing the audible gains in clarity would be negligible.  I'd be willing to bet that a blind side by side would sound identical to human ears without spending many hours familiarizing your ears to the slight difference in the modified microphones sound.

[it-goes-to-eleven]

Isn't the cable for the CCM is just basically a balanced mic cable, is there anything going on in the XLR housing itself?

Can you buy the raw cable that is used in the KCx cables?

The CCM and KC5 active cables are unbalanced.   The KC5 and Neumann body based active setups have the advantage of, obviously, being balanced after the bodies. I think that's important if you ever do long runs or hang mics close to lights, etc.  For what we do, I really wouldn't want to have a lot of unbalanced cable on my actives.

There is nothing funky going on in the CCM xlr housing (like with the 402x). The CCM could be converted to a stubbie xlr... and I'd be all over that if I had a pair.

Jerry at Posthorn does recabling of choeps actives and is a good source for Schoeps parts and cable. He typically has the parts in stock to repair a torn out schoeps active cable. So that greatly differentiates him from all of the other Schoeps vendors for me.

The KC5 cable is now $8/meter.  It went up a lot on the recent increase.  I will be recabling my kc5's soon but I haven't decided what I'm going to use. Probably the standard stuff.

[Lil Kim Jong-Il]

Unbalanced cables only have a +hot and -hot, no ground, which means that RF noise, cycle hums and ground loops are not eliminated resulting in noisy signal.  That's just some extreme basics on cables.

Actually an unbalanced cable does transfer a signal voltage referenced to ground.  Assuming that all other conditions, such as shielding and EMI field strength are the same, an unbalanced and balanced cable are subject to the same interference.  It's the summing of the +signal and inverse -signal at the differential input that negates audible interference.  Google for "common mode rejection" if you are interested in the detailed explanation.



One more thing:  Has anyone ever snipped the LC3 wire and verified that it's unbalanced?  The LC3 ends have three signal connection points on each end.

[Evil Taper]

Yep, the balancing transformer only reads differences in voltage so the RF is deleted during balancing.