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There ARE stupid questions - plenty of them.
Here's mine: If I use the balanced output of a component, but convert to SE via an XLR->RCA cable, to go to a single-ended line stage, then convert back to balanced via an RCA-to-XLR interconnect to drive an amp via its balanced inputs, do I retain the advantages of balanced operation or the stated benefits of the balanced outputs of the DAC and the balanced inputs of the amp?
The components are Metrum Pavane DAC -> Placette Linestage (single-ended only) -> Pass XA60.5 monoblocks. Both the DAC and the amps give better performance via their balanced outputs [inputs]. Does it all go to heck in the SE conversion inside the Placette? I think it certainly must, but thinking about it from the electron's point of view, I'm not quite getting the "why" of it, if you get me.
It may be the bourbon.
Follow Ups:
Single-ended and balanced operation are inherently incompatible.
By that I mean you have one or the other and not both. There is no such thing as 'quasi-balanced' (that's mumbo-jumbo for 'single-ended).
When you tie one of the outputs of a balanced source to ground, the result is single ended and you loose the benefits of balanced operation.
As the line stage is SE neither connection will confer the potential benefits of balanced (differential) operation. You have SE connection throughout which just happens to have an XLR connector at one end of either cable.
If you connected the DAC via its balanced outputs to the balanced amplifier then this connection would be balanced and reject noise picked up via the cable in the manner described by other respondents to this post. Obviously you would then have no way of controlling volume if the DAC has no such control. However even if this can be overcome by controlling volume from, say, a player application, there is still no guarantee that you will get better sound over the SE connection especially as the line stage may provide subjective benefits ( so far I have not found direct DAC/power amp connection to offer unalloyed benefits despite the logic that it should sound better).
Speaking generally, balanced connection v. SE seems to depend upon the success of the implementation of either and results that run counter to what is expected may be the outcome in practice. It seems to require a suck it and see approach.
To take full advantage of balanced equipment the whole system needs to be balanced, from source to amplifier. Including cables, especially long cables since they are the most likely to pick up EMI.
Yes, I've read that many times. Can you explain what happens in the balanced-> SE-> balanced conversion that loses the balanced advantages?
Balanced splits the signal into 2 halves or phases, a positive and negative, each on its own conductor. When the 2 halves (plus and minus) are recombined any common noise that was picked up on each conductor is cancelled out since the noise is not out of phase. A SE signal is on one conductor so there is no cancelling of any noise picked up.
Differentially balanced means there are separate circuits for the + and - sections of the signal. Most of the time, companies put XLR connections on their components just as bragging rights....these connections are not balanced. Because of the seperate circuits on balanced components, they are more expensive and sound better than single ended circuits.
Edits: 10/22/16
Remember a balanced cable only splits and rejoins both polarities of the signal to remove any noise gained while in the cable.Personally I think you are loosing more just by having all those connections and adapters. If you could just run one cable between source and passive, then passive to amp you would be gaining more.
If I read this correctly I think you would just be better off with a standard RCA cable then flipping back and forth.
Edits: 10/23/16
I guess the heat of the day was catching up with me.
Yes you need a balanced from end to end. And yes the cable itself does NOT split the signal.
" Remember a balanced cable only splits and rejoins both polarities of the signal to remove any noise gained while in the cable. "
I don't think this is correct. The cable doesn't do the splitting and rejoining, the circuitry in the components at the send and receive ends does this. The cable is just a signal path between the two circuits. In the OP's situation he has an SE connection at either the send or receive end. Hence the signal in the cable remains SE throughout.
No adapters - these are XLR-> RCA and RCA-> XLR cables.
Going from balanced to se then se to balanced will not give you balanced. The chain is broken. There is some mentioned that there may be some benefit in this configuration that the cable itself is balanced. But is it? Likely wired for se at the terminations only and no extra cable internally. Just saying.
Cheers!
Jonesy
"I know just enough to get into trouble. But not enough to get out of it."
You are quite right. The cable itself isn't balanced. It is just an expression that we use to avoid having to call it a " cable terminated for the connection of balanced output and input circuits" or somesuch.
It can have an extra cable internally i.e. a 3 rather than 2 core cable or the earth can be routed via the shield leaving the 2 conductors to carry + or - signals (not best practice). In an RCA to XLR cable like the OP's the negative or "cold" signal wire will be attached to the screen.
I know I'm only an end user but it seems to me that a balanced cable should be used for long runs. Like in a studio where the cables are 20+ feet long.
A typical stereo interconnect of 2-3". Seems like it's adding MORE crap in the signal path by having two extra circuits to first split and then rejoin the signal.
How would you know that those transistors aren't out of balance and ADDING distortion????? The typical better quality 3" cable does have shielding to prevent EMI - are we living too near a nuclear reactor or something?
It just seems like a lot of work to reinvent the cable again.
In a typical home listening environment with a small number of short cable runs, the common mode noise rejection improvement you get from balanced cabling shouldn't matter much.
A bigger reason to prefer balanced connections is that ground loop problems are much less common. In a system with single ended connections, the signal grounds of the different components are tied together through the same conductor which is carrying any ground loop currents. In a system with properly implemented balanced connections, the signal grounds of different components don't need to be tied together, and any ground loop currents flow on a conductor that isn't carrying the signal or its ground reference. Of course, not all balanced connections are created equally.
There is also an argument for implementing balanced circuitry internal to a component, for rejecting common mode noise generated inside the component. This is most commonly seen in power amplifiers to minimize power supply hum, because they have large power supplies that produce a lot of EMI.
Yes, you've alighted on the most common objections to balanced circuitry.
In particular the ideal requirement for the + and - circuits (or phase and anti-phase) to be identical can cost a lot in rejected components that do not match with their counterparts. I recall reading a report of a visit to FM Acoustics in Switzerland. The reporter was amazed at the bins of components awaiting disposal (or onward sale to other manufacturers). I am unsure if many manufacturers go to this length but it helps explain the stratospheric pricing of FM products.
In practice a balanced system may or may not perform better than a single ended one. It is all down to implementation and, I expect, the designer's original concept. I am pretty certain that quite a lot of consumer audio electronics were conceived as SE components only to have a balanced option piggy backed into the design for marketing reasons and where shortcuts for commercial reasons have been made.
NB: My own system is balanced but I made sure that I tried it in SE mode before deciding to keep it balanced. Probably because most of my equipment was made by firms with a pro-audio background where balanced is the standard. Also my interconnects are up to 5m long.
So, suck it and see is my motto.
Doubt your setup is true balanced , xlr inputs alone dont mean the setup is balanced ...
In exactly what way is a 4 box dCS Paganini (using AES/EBU connections and balnced outputs) into an ATC SAC2 or SPL Phonitor 2 into a pair of ATC SCM 50 ASLs not balanced? Please explain in full. All have fully differential balanced circuits.All are listed in my profile and I assume that you bothered to find out before posting.
Edits: 10/25/16
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