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Post by scubadiver on Mar 30, 2015 17:27:25 GMT -5
I debated on posting this question on the "Stupid Question Zone", but decided to try it here.... (If it gets moved to the Stupid Question board, I won't be offended...) 
If you connect non-differential amps to the XMC-1 with XLR connections (like the XPA-5), I assume you are not using the XMC-1 to it's fullest potential as if you connected "fully balanced differential amps" like the XPA-1L.
Correct?
And conversely, if I buy a set of XPA-1L's, and connect them with the same XLR cables to a non-differential processor, I'm not going to fully utilize the extra money spent to get the 1L's...
Again, am I correct?
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Post by deltadube on Mar 30, 2015 17:32:35 GMT -5
its good to have balanced in your life!!!
xpa 1ls be nicer than xpa 5s both are balanced.. but you can use balanced and un balanced interconnects... rca vs xlr..
u want the quad differential mono blocks.. and free membership into the mono block society eh..
xpa 5 with a pair of xpa 1s will work real nice for movies and you get the best for 2 channel too..
cheers
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Post by garbulky on Mar 30, 2015 17:33:11 GMT -5
Correct on both counts AFAIK. Having said that, I didn't hear a massive difference between the two. But it is the technically best way to hook things up.
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Post by Dark Ranger on Mar 30, 2015 18:13:52 GMT -5
If you connect non-differential amps to the XMC-1 with XLR connections (like the XPA-5), I assume you are not using the XMC-1 to it's fullest potential as if you connected "fully balanced differential amps" like the XPA-1L. Correct? Theoretically, yes. Realistically, you probably won't hear an audible difference. And conversely, if I buy a set of XPA-1L's, and connect them with the same XLR cables to a non-differential processor, I'm not going to fully utilize the extra money spent to get the 1L's... Again, am I correct? Again, theoretically, yes. Realistically, you probably won't hear an audible difference. KeithL or Lonnie can better explain the technical advantages of a fully-balanced system. I'm not going to pretend I can explain them. However, while there are measurable improvements, they are not always audible depending on a lot of factors. I'd be more concerned with paring a quality processor with a quality amp than ensuring it's fully-differential. If you have the cash and want to give it a go, well, there's nothing wrong with that.  Note: unless I'm mistaken, I think the XMC-1 is fully differential on front left/right channels only under Reference Stereo mode. I don't own an XMC-1, but that's what I've seen on the boards so far. |
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Post by AudioHTIT on Mar 30, 2015 21:17:51 GMT -5
I debated on posting this question on the "Stupid Question Zone", but decided to try it here.... (If it gets moved to the Stupid Question board, I won't be offended...)
If you connect non-differential amps to the XMC-1 with XLR connections (like the XPA-5), I assume you are not using the XMC-1 to it's fullest potential as if you connected "fully balanced differential amps" like the XPA-1L.
Correct?
And conversely, if I buy a set of XPA-1L's, and connect them with the same XLR cables to a non-differential processor, I'm not going to fully utilize the extra money spent to get the 1L's...
Again, am I correct?
I thought only the L/R channels of the XMC-1 were fully balanced? One of the features of the XMR-1 will be that all channels are full balanced. As such if you got a pair of XPA-1L's to use to drive your L/R speakers, and an XPA-5 to drive the rest of your system you would be matching the fully balanced channels and amps together (and you'd have a very nice system). The 1L's quality comes from more than their fully balanced architecture (like the large Class A bias), so even with less than a fully balanced preamp they'd sound good. |
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Post by Gary Cook on Mar 30, 2015 21:36:47 GMT -5
I have no idea what "fully balanced" means, what I do know is; An XPA-5 is balanced and dual differential. An XPA-1L is balanced and quad differential. The fact is they are both balanced and they both have differential circuitry. The difference between dual and quad is in the design of the differential circuitry, what is important is that they are both differential. Keith explains it better; All else being equal... blah... blah... blah...  * A balanced connection can be quieter - because any noise picked up equally in both wires cancels out. * A differential circuit design can have lower distortion - because any distortion produced equally by both (identical) modules or channels cancels out. (Beyond that, since this cancellation usually favors certain harmonics, the overall proportion of the various harmonics will be different as well.) However, "all else" is never "exactly equal" anyway - if the device is balanced, you'll need an extra stage to convert unbalanced inputs to balanced; if it's unbalanced, then you'll need an extra stage to convert in that direction - and you'll never know if the difference you're hearing is simply that extra stage. For example, if you connect an unbalanced input to a fully differential amplifier, you might end up with lower distortion (because the amp itself is differential), or you might end up with higher distortion (because the unbalanced-to-balanced converter section adds a tiny bit of distortion itself). This is why it's not uncommon for the balanced and unbalanced inputs on a given device to sound slightly different (and either could be the better one). I recall a "funny" review about an amplifier modification (on a Dynaco St400 - if anyone remembers those). The modification added a switch that could be used to bypass one of the gain stages - based on the premise that every gain stage makes distortion so, if you didn't need the gain, bypassing that stage would lower your distortion. To make a long story short, it turned out that the contact resistance on the switch itself introduced MORE distortion than the stage it bypassed... so the distortion was actually lower when the signal went through the transistor instead of the switch... The more accurate way of saying things is that a differential design offers certain engineering advantages which, if properly taken advantage of, can allow you to design an amplifier with lower distortion (which might be audible as better sound). All the stuff about "dual differential" and "quad differential" is circuit details about how exactly everything is connected together... and our quad-differential circuitry offers a few more benefits than doing it some other ways. However, in the end, you should always judge an amplifier on the results rather than the means (using a quad differential circuit is no guarantee of low distortion or good sound - it just helps make it easier to get there). And a balanced connection is only SPECIFICALLY going to sound better if you are having trouble with noise being picked up on the connection - in which case that noise should be reduced quite a bit. Otherwise, which will sound better will depend on the actual circuitry that was used on the equipment at either end of the connection. (In most cases you won't necessarily hear a difference at all.) Incidentally, the "3 dB benefit of balanced connections" - above and beyond cancellation of noise picked up in the cable - is theoretical. ( ASSUMING that the dominant noise was from the output stage of the source device and the input stage of the destination device, and ASSUMING that the balanced circuitry didn't add any noise of its own, the signal would be doubled - because you're adding two equal and out-of-phase signals - while the noise, being random, would average instead - so the ratio between them would improve a tiny bit. However, those assumptions aren't always true.) With most amplifiers, the overall S/N depends on all sorts of things, and they may or may not be a few dB quieter when you use one input or the other... Considering how quiet most amplifiers are these days, and the fact that 3 dB is barely audible, I wouldn't worry too much about it. Cheers Gary |
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Post by AudioHTIT on Mar 30, 2015 21:50:14 GMT -5
I have no idea what "fully balanced" means, what I do know is; An XPA-5 is balanced and dual differential. An XPA-1L is balanced and quad differential. The fact is they are both balanced and they both have differential circuitry. The difference between dual and quad is in the design of the differential circuitry, what is important is that they are both differential. I believe the XPA-5 only has a balanced input (dual differential), whereas the XPA-1L has a completely balanced signal path from input to output (quad differential). Both can benefit from a balanced cable connection. |
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Post by brutiarti on Mar 30, 2015 21:51:57 GMT -5
I think that only monoblocks are fully balanced
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Post by AudioHTIT on Mar 30, 2015 21:54:41 GMT -5
I think that only monoblocks are fully balanced In Emotiva's case this is true (with the exception of the XPA-100), but not so with other manufacturers, some have fully balanced multi-channel amps. |
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Post by brutiarti on Mar 30, 2015 22:03:11 GMT -5
Probably you are talking big bucks on those I think that only monoblocks are fully balanced In Emotiva's case this is true (with the exception of the XPA-100), but not so with other manufacturers, some have fully balanced multi-channel amps. |
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Post by vcautokid on Mar 30, 2015 22:25:31 GMT -5
Absolutely true Balanced is theoretically best where possible. No the XMC-1 will not turn into an Area 51 unknown space ship if you don't. It Runs superbly single ended too! The feature of common mode noise cancellation is a bonus while running long leads like say to your Airmotiv's running as surrounds for instance while using balanced. Is it an audible difference, probably not vs. single ended for most, some may differ, cool makes this hobby fun we don't hear the same. I have been running both single ended, and Balanced for years in both a project studio, and my audio systems, as well as my high school system that my teacher was too lazy to keep up. So I took it over. In a world of this, and that, Balanced is a wonderful thing if you want it, or need it, but Single Ended for many folks will work just fine too. Pick your connection, both will be great, need the noise cancellation and perhaps lower noise floor, balanced is there for you. But don't feel you are going without if you have to run single ended.
The XMC-1 will do great with both.
A balanced perspective. IMHO
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Post by scubadiver on Mar 30, 2015 22:42:17 GMT -5
This is all wonderful info.... Thanks to all!
So in a balanced configuration (say an XMC-1 using an XMA-1L) are you "balanced" all the way from the preamp down to the speaker, or do the potential benefits of balancing end at the amp's binding posts?
In other words, are you balancing the signal path from the preamp through the amp and down to the speaker, or just the signal path between the preamp and the amp?
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Post by AudioHTIT on Mar 30, 2015 22:42:26 GMT -5
Probably you are talking big bucks on those In Emotiva's case this is true (with the exception of the XPA-100), but not so with other manufacturers, some have fully balanced multi-channel amps. Certainly they are more expensive than Emo, but not all are really big bucks (which of course is relative). Outlaw and Wyred-4-Sound (to name a couple) have multi-channel amps which are fully balanced and I would still call them reasonably priced. |
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Post by AudioHTIT on Mar 30, 2015 22:50:40 GMT -5
This is all wonderful info.... Thanks to all! So in a balanced configuration (say an XMC-1 using an XMA-1L) are you "balanced" all the way from the preamp down to the speaker, or do the potential benefits of balancing end at the amp's binding posts? In other words, are you balancing the signal path from the preamp through the amp and down to the speaker, or just the signal path between the preamp and the amp? You are balanced through the XMC-1's L/R channel path, through the cables, and through the XPA-1L; it ends at the speaker terminals. |
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Post by creimes on Mar 31, 2015 0:34:15 GMT -5
I never heard a difference between my XPA-1L's and XPA-5 Gen2, they both sounded grrrrrreat  |
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Post by repeetavx on Mar 31, 2015 1:29:57 GMT -5
So in a balanced configuration (say an XMC-1 using an XMA-1L) are you "balanced" all the way from the preamp down to the speaker, or do the potential benefits of balancing end at the amp's binding posts? In other words, are you balancing the signal path from the preamp through the amp and down to the speaker, or just the signal path between the preamp and the amp? Balanced means that you have two signals working through the system. A normal one, and an upside down one. Any noise that attaches itself to the signal will attach itself "right side up" to both signals. When the amp "reconciles" the signal, anything that isn't both right side up and upside down at the same time is noise. A fully balanced amplifier will amplify the two complementary signals simultaneously and "reconcile" the two signals just before it sends it to the speakers. An "unbalanced" amplifier will "reconcile" the signal after it receives it, and then amplify the signal for the speakers. |
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Post by vcautokid on Mar 31, 2015 4:11:08 GMT -5
Anyway you have it. Balanced yes as the above post will give you more in the long run. Will you fully realize the potential vs. Single ended is a thing where test data is helpful so you can see where the difference,lies. Usually better signal to noise, and higher voltage output. Is that something you can appreciate everyday? You could.
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Post by audiosyndrome on Mar 31, 2015 9:17:36 GMT -5
If your cabling in the back of the rack is a clusterf__k (a commonly accepted term in the engineering community but I thought I'd abbreviate it anyway) then a fully balanced system such as an XMC-1 and an XPA-1L could make a difference by eliminating pickup, hum, etc.. Otherwise I agree that fully balanced system may or may not make an audible difference in audio quality.
But please stop talking about dual differential, quad differential, etc. These are just terms for the input stage of an any amp. Has nothing to do with whether or not its a balanced amplifier. A product is NOT fully balanced unless the specification states it is fully balanced. XPA-1, XPA-1L, XPR-1. That's it.
Russ
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Chris
Minor Hero
Posts: 94
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Post by Chris on Mar 31, 2015 10:15:17 GMT -5
Little bit of geek speak:
"A differential amplifier is a type of electronic amplifier that amplifies the difference between two input voltages but suppresses any voltage common to the two inputs.[1] It is an analog circuit with two inputs and and one output in which the output is ideally proportional to the difference between the two voltages"
In basic terms its just saying it does a good job of rejecting noise in the system. If you have a differential source you are essentially getting as pure a signal out to your amplifier as possible. Coupled with a differential amplifier, what little noise may have made it back into the system at the point of the amp is again diminished due to the differential part and again you are sending as pure a signal as you can out.
In real life the noise floor is already so low that you are most likely going to not notice any difference. Same goes for the amp, the THD, or SNR was something like -96db or -118db in the manual. No human alive would hear noise at that low a db compared to the reference signal level.
In short: you will enjoy just as good sound quality out of either type of amp paired with a superb receiver like the XMC-1
One note from the poster above "A product is NOT fully balanced unless the specification states it is fully balanced. XPA-1, XPA-1L, XPR-1. That's it."
--I don't think there is anything between "balanced" and "fully balanced" it either is or it isn't. We need to be careful and make sure we are talking about the same things. I believe the original poster was referring to the connections on the back. If there is some other part of the amp that the term balanced refers to please point us to the technical documentation that explains the differences.
So I would venture that the XPA series is "balanced" since it offers those types of inputs.
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Post by AudioHTIT on Mar 31, 2015 14:10:05 GMT -5
One note from the poster above "A product is NOT fully balanced unless the specification states it is fully balanced. XPA-1, XPA-1L, XPR-1. That's it." --I don't think there is anything between "balanced" and "fully balanced" it either is or it isn't. We need to be careful and make sure we are talking about the same things. I believe the original poster was referring to the connections on the back. If there is some other part of the amp that the term balanced refers to please point us to the technical documentation that explains the differences. So I would venture that the XPA series is "balanced" since it offers those types of inputs. Actually there is a difference between the three monoblocks he listed, and the other XPA amps. Only those monoblock models are fully balanced from input to output, the other XPA's (like the XPA-5) only have a balanced input circuit, the amplifier itself is single ended. |
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