Balanced out to unbalanced in at amp

jmusica

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Love my balanced cables, took years to find them. New amp (Enleum) has only unbalanced/RCA inputs.

Is it bad to use an adapter (Cardas make 'em, someone just pointed that out to me) to go from balanced/XLR out from Lumin X1 to unbalanced/RCA on the Enleum? Bad as-in 1) will sound like crap, or, bad as-in 2) something will blow up.
 
Going balanced to unbalanced is a crap-shoot depending on how the manufacturer implemented their balanced output. A lot of electronic balanced implementations can be operated correctly from the (+) output xlr pin 2, while grounding the (-) audio output, xlr pin 3, to the shield of the unbalanced cable.

In some implementations, if you ground the (-) pin you will short out half the balanced output and cause current to flow in the signal ground. Best to contact the manufacturer of the balanced output device to find out what they are doing and what will work. This is not trivial.
 
I think there is a Lumin representative on the forum. If they could chime in with a schematic of the output stage, (PM is OK) than I could help steer you in the right direction wrt finding the optimum interface solution.
 
Love my balanced cables, took years to find them. New amp (Enleum) has only unbalanced/RCA inputs.

Is it bad to use an adapter (Cardas make 'em, someone just pointed that out to me) to go from balanced/XLR out from Lumin X1 to unbalanced/RCA on the Enleum? Bad as-in 1) will sound like crap, or, bad as-in 2) something will blow up.

It should work fine, plus there are cheaper alternatives to stupidly pricey Cardas stuff that will to work well.

The standard polarity for XLR connections is a show in the following diagram: Cardas and other XLR male to RCA adapters will respect this scheme. There are very few exceptions out there, mostly among old equipment.

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Here is an example of the sort of XLR to RCA cable that would work for you. Note that the XLR end of the cable is female which is necessary to connect to the male output Lumin X1.

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I use a transformer based balanced to unbalanced converter from Jensen. I was getting hum from long Unbalanced cables.
 
I think I need to provide a bit more information, so here goes.

Balanced inputs all behave pretty much the same way. But balanced outputs are either floating or hard balanced. If they are floating, you can short one phase to ground, and the other phase just compensates, providing a perfect unbalanced signal. The most pefect floating output is a transformer, most gear has electronic floating outputs that work in a similar way.

Hard balanced outputs cannot be shorted to ground, however each phase is referenced to the chassis (pin 3) ground, so you can treat them as two unbalanced outputs, out of phase with each other.

So knowing if a balanced output is floating or hard balanced is really important, because the interface cable will be wired differently in each case.

If you don’t know and can’t find out, using a transformer interface as bones suggested is the best course of action.
 
I think I need to provide a bit more information, so here goes.

Balanced inputs all behave pretty much the same way. But balanced outputs are either floating or hard balanced. If they are floating, you can short one phase to ground, and the other phase just compensates, providing a perfect unbalanced signal. The most pefect floating output is a transformer, most gear has electronic floating outputs that work in a similar way.

Hard balanced outputs cannot be shorted to ground, however each phase is referenced to the chassis (pin 3) ground, so you can treat them as two unbalanced outputs, out of phase with each other.

So knowing if a balanced output is floating or hard balanced is really important, because the interface cable will be wired differently in each case.

If you don’t know and can’t find out, using a transformer interface as bones suggested is the best course of action.

I'm certainly not doubting the correctness of you Floating versus Hard balance on output explanation. But I wonder how prevalent the 'Hard' situation is? Personally in many instance I have driven SE devices from balanced ones without problems by effectively running the '-' signal to ground; that includes both purchase and home-made cables.

From what I've observed, XLR to SE adapters and cables effect the the '6' wiring as shown in this RANE table and diagram: I guess they assume the 'transformer or cross-coupled output stage' situation and that the '-' signal is routed to ground...
gi.mpl
 
Boulder makes some excellent ones. If you get a hum, ISOMAX makes a transformer decoupling unit ($299) that works like a charm.


Sent from my iPhone using Tapatalk Pro
 
Jensen ISO-MAX

PI-2XX | Jensen Transformers

I chose XLR in, and RCA out. XLR cables from Pre directly to balanced amp, or to the iso-max box with short RCAs to the unbalanced amp. I use this to prevent hum.

The Boulder 508 came with their adapters, which connect my unbalanced turntable to it.
 
I'm certainly not doubting the correctness of you Floating versus Hard balance on output explanation. But I wonder how prevalent the 'Hard' situation is?
Bill, I don’t know how prevalent it is and think that’s actually unknowable. Fixed has an advantage in simplicity and potential overall fidelity as fewer parts are needed to implement it.

I do know that, early in my career, I singlehandedly took a 50 kW clear channel major metro AM radio station off the air for several minutes during prime drive time by ASSUMING that a studio device had a floating output when it really had a hard balanced output. ;) I didn’t get fired, but I sure got a talking-to. So maybe I’m over-sensitive to it.

This is one of those situations where the audible impact of an improper connection may be subtle. Like the Balanced to unbalanced cable does not sound as good as going unbalanced all the way. Or even that major peaks are a little distorted but everything else is ok. Hard to know how a hard balanced output will behave if you short one side to ground.

So I always want to know how the balanced output of my equipment operates, as opposed to assuming it is floating.
 
Bill, I don’t know how prevalent it is and think that’s actually unknowable. Fixed has an advantage in simplicity and potential overall fidelity as fewer parts are needed to implement it.

I do know that, early in my career, I singlehandedly took a 50 kW clear channel major metro AM radio station off the air for several minutes during prime drive time by ASSUMING that a studio device had a floating output when it really had a hard balanced output. ;) I didn’t get fired, but I sure got a talking-to. So maybe I’m over-sensitive to it.

This is one of those situations where the audible impact of an improper connection may be subtle. Like the Balanced to unbalanced cable does not sound as good as going unbalanced all the way. Or even that major peaks are a little distorted but everything else is ok. Hard to know how a hard balanced output will behave if you short one side to ground.

So I always want to know how the balanced output of my equipment operates, as opposed to assuming it is floating.

My ignorance of the floating vs. hard subtlety naively allowed me to venture forth all unawares. Fortunately using the XLR->RCA cable has worked fine in my instances.
 
The problem with not knowing if your balanced output has an active pin 3 (negative) is if you do use a cable or adapter that ties that to ground, you are essentially shorting a signal output which can cause damage, or at the very least stress the circuit which will probably cause distortion. If you float pin 3, when it should be tied to ground, you might be able to tell immediately because it will most likely negatively impact the frequency response which will be very audible.
 
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