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Post by gentlejax on Dec 21, 2019 12:24:00 GMT -5
I noticed the volume output is much different on the XSP-1 than on my Sherbourn PRE-1 ...Its ok I get it ..we are talking different things here but that is not the question..
I was finally reading the manual and it says when using BALANCED inputs / outputs the bass management is defeated and speakers are set to full range? is this correct?
so if I want to use the crossovers (if you call the knob that) I have to run unbalanced inputs / outputs? why? or did I read that wrong. I always run balanced cause the signal is usually stronger to my pro amps. and hell all this expense for BALANCED circuitry id like to use it. but honestly already had that on my PRE-1 so I am not sure what I have gained by spending the extra $300 more that I have invested.
maybe I am reading it wrong. my signal goes from the XSP-1 to a EQ that has balanced in/outs to my pro amps.
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Post by Gary Cook on Dec 21, 2019 16:19:25 GMT -5
Firstly Balanced Input is irrelevant to the output cross overs (filters), balanced (XLR) or unbalanced (RCA). So you can always run Balanced (XLR) inputs regardless of the desired output.
The low pass filter has no effect on the FL and FR Balanced output, flick the switch to Low Pass and trim the sub woofer to whatever upper frequency limit you want. Same with the 12/24 db slope selection.
The high pass filter is the one that has the effect on the FL and FR balanced output, using it negates the balanced output from the pre amp. You can still use the XLR or the RCA output.
If you want to run fully balanced all the way from the source through the pre amp and through the power amps then you need to flick the High Pass filter switch to Full Range.
Why? In simple terms, to run fully balanced means that there has to be 2 complete pre amp circuits for each channel. Once you engage the high pass filter they have to be combined and you only get 1 pre amp circuit for each channel, hence unbalanced output.
I run my system fully balanced all the way and I have blended in the sub woofer as the FL and FR speakers naturally roll off (around 60hz, 12db slope). This takes a bit of tuning, via measurement and mostly a lot of listening, to get right.
Merry Xmas
Gary
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Post by dimitryz on Jan 21, 2020 21:19:22 GMT -5
I think above post is incorrect. Use of crossovers, both high and low pass, is entirely separate from what output you choose to use.
XSP-1 does have fully differential architecture and dual filters. Bass management filter settings (and tone settings, if you choose to use them) are active on both balanced and unbalanced outputs. Furthermore, balanced and unbalanced outputs are active simultaneously - if you use balanced outputs, for example, unbalanced ones are available to feed other equipment.
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Post by Gary Cook on Jan 21, 2020 21:31:48 GMT -5
I think above post is incorrect. Use of crossovers, both high and low pass, is entirely separate from what output you choose to use. XSP-1 does have fully differential architecture and dual filters. Bass management filter settings (and tone settings, if you choose to use them) are active on both balanced and unbalanced outputs. Furthermore, balanced and unbalanced outputs are active simultaneously - if you use balanced outputs, for example, unbalanced ones are available to feed other equipment. I don't see anything different in what you posted and what I posted. It is just expressed differently. Cheers Gary |
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Post by dimitryz on Jan 21, 2020 22:17:39 GMT -5
I think above post is incorrect. Use of crossovers, both high and low pass, is entirely separate from what output you choose to use. XSP-1 does have fully differential architecture and dual filters. Bass management filter settings (and tone settings, if you choose to use them) are active on both balanced and unbalanced outputs. Furthermore, balanced and unbalanced outputs are active simultaneously - if you use balanced outputs, for example, unbalanced ones are available to feed other equipment. I don't see anything different in what you posted and what I posted. It is just expressed differently. Cheers Gary Paragraphs 4 and 5 are incorrect. They imply that one can't use bass management with balanced outputs, or that the system becomes "not fully balanced" if you choose to use high or low filters. Output type and use or nonuse of bass management or tone controls are entirely unrelated things. |
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Post by garbulky on Jan 21, 2020 23:07:22 GMT -5
I don't see anything different in what you posted and what I posted. It is just expressed differently. Cheers Gary Paragraphs 4 and 5 are incorrect. They imply that one can't use bass management with balanced outputs, or that the system becomes "not fully balanced" if you choose to use high or low filters. Output type and use or nonuse of bass management or tone controls are entirely unrelated things. Actually the system is NOT fully balanced when you choose whatever filter Gary Cook said. However, you can still use the XLR outputs. P.20 of manual |
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Post by dimitryz on Jan 22, 2020 1:09:47 GMT -5
Paragraphs 4 and 5 are incorrect. They imply that one can't use bass management with balanced outputs, or that the system becomes "not fully balanced" if you choose to use high or low filters. Output type and use or nonuse of bass management or tone controls are entirely unrelated things. Actually the system is NOT fully balanced when you choose whatever filter Gary Cook said. However, you can still use the XLR outputs. P.20 of manual I forgot about this section! However, bass management still works, as the bass output remain both filtered and balanced. I use main output direct with the aft panel switch. Main XLR outputs feed the upper panels of my speakers (viavpair of XPA-1's). Bass outputs are used in filtered mode, with XLR outputs feeding my speakers' lower biwire inputs (via pair of bridged XPA-2's) and RCA outputs feeding a pair of subs. During initial setup listening tests, I was certain that the setting of the main outputs to high pass mode with the aft switch WAS audible. I always use direct mode on the remote. I don't think this setting disabled or overwrote the setting of the mechanical switch on the aft panel. So I guess I actually disagree with the statement in the manual. |
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Post by Gary Cook on Jan 22, 2020 5:19:03 GMT -5
Actually the system is NOT fully balanced when you choose whatever filter Gary Cook said. However, you can still use the XLR outputs. P.20 of manual I forgot about this section! However, bass management still works, as the bass output remain both filtered and balanced. I use main output direct with the aft panel switch. Main XLR outputs feed the upper panels of my speakers (viavpair of XPA-1's). Bass outputs are used in filtered mode, with XLR outputs feeding my speakers' lower biwire inputs (via pair of bridged XPA-2's) and RCA outputs feeding a pair of subs. During initial setup listening tests, I was certain that the setting of the main outputs to high pass mode with the aft switch WAS audible. I always use direct mode on the remote. I don't think this setting disabled or overwrote the setting of the mechanical switch on the aft panel. So I guess I actually disagree with the statement in the manual. I think you are confusing “balanced outputs” for the FL and FR which work even when the high pass filter is utilised. With the “fully balanced discrete differential circuitry” for the FL and FR which is disengaged when the high pass filter is utilised. Utilising the high pass filter requires combining the discrete paths, so there is only one output signal per channel. Which emanates from both the XLR outputs and the RCA outputs. When the high pass filter is not utilised there are 2 outputs being one + and one - per channel. This enables a fully balanced, discrete connection to the power amplifier. For a detailed explanation on how fully balanced discrete differential circuitry works try a search for posts by KeithL quoting “differential” or “discrete”. Cheers Gary |
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Post by Boomzilla on Jan 22, 2020 7:53:17 GMT -5
garbulky hit it on the head. The manual says it explicitly. If you have a balanced input, and are using the balanced outputs, then the fully-differential circuitry is maintained throughout the signal path, and the preamp can rightly be said to be "fully balanced." However, if you engage the tone controls, then the XLR full-range outputs still work, but the output signal is no longer fully balanced. Likewise, if you use the bass-management, the XLR outputs and the subwoofer outputs still work, but the output signal is no longer fully balanced. So the XSP-1 can be said to be a "fully-differential, balanced-circuitry preamp" sometimes. But never when the tone controls are engaged or when the bass-management is used. Boom PS: This is not unusual among preamplifier makers. Since the cost of the components doubles when designing completely balanced circuits, it is common to revert to unbalanced mode when using "peripheral" functions such as tone control and bass management to save money. I've never seen a design with balanced tone controls, for example. There may be one, but they're definitely rare. And this statement applies at ALL price levels. I'm currently reviewing an $8,000 preamp that, despite having XLR input and output, is not fully balanced.
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Post by dimitryz on Jan 22, 2020 8:46:48 GMT -5
garbulky hit it on the head. The manual says it explicitly. If you have a balanced input, and are using the balanced outputs, then the fully-differential circuitry is maintained throughout the signal path, and the preamp can rightly be said to be "fully balanced." However, if you engage the tone controls, then the XLR full-range outputs still work, but the output signal is no longer fully balanced. Likewise, if you use the bass-management, the XLR outputs and the subwoofer outputs still work, but the output signal is no longer fully balanced. So the XSP-1 can be said to be a "fully-differential, balanced-circuitry preamp" sometimes. But never when the tone controls are engaged or when the bass-management is used. Boom PS: This is not unusual among preamplifier makers. Since the cost of the components doubles when designing completely balanced circuits, it is common to revert to unbalanced mode when using "peripheral" functions such as tone control and bass management to save money. I've never seen a design with balanced tone controls, for example. There may be one, but they're definitely rare. And this statement applies at ALL price levels. I'm currently reviewing an $8,000 preamp that, despite having XLR input and output, is not fully balanced. There is a lot of confusion here. There is no such thing as XLR outputs "still working" but not being "fully balanced" - output of an XLR connector is always balanced by definition.. Also, to make unbalanced from balanced, you don't need to "combine" anything, Balanced signal consists of two unbalanced signals, out of phase with one another (pins 2 and 3 on rhe XLR connector) referenced to neutral (pin 1). You simply use the "hot" signal. Original poster is interpreting the manual to mean the XLR outputs are disabled if he uses bass management. This is expressly NOT the case. They just don't have as pure a path from the inputs. That's why I choose to run the mains directly and allow the subs to fill in bellow 50 hz. This way, whatever impurity is in the signal path only affects rhe subs - much less objectionable. |
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Post by Boomzilla on Jan 22, 2020 10:50:25 GMT -5
I think that you're mistaken, dimitryz. I have RCA to XLR (unbalanced to balanced) adaptor cables that work fine. Therefore your statement that "output of an XLR connector is always balanced by definition" must be wrong. I could be mistaken, but I don't think so. I also see numerous preamplifiers, for example, that have XLR inputs and outputs, yet the manufacturers clearly state that the preamps do NOT have balanced circuitry. The Emotiva XSP-1 is a case in point. Used in "pure direct" mode, the preamp DOES have fully balanced, differential circuitry from input to output. But if not in direct mode, the XLR outputs are still active - but no longer balanced. |
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Post by dimitryz on Jan 22, 2020 11:51:23 GMT -5
I think that you're mistaken, dimitryz. I have RCA to XLR (unbalanced to balanced) adaptor cables that work fine. Therefore your statement that "output of an XLR connector is always balanced by definition" must be wrong. I could be mistaken, but I don't think so. I also see numerous preamplifiers, for example, that have XLR inputs and outputs, yet the manufacturers clearly state that the preamps do NOT have balanced circuitry. The Emotiva XSP-1 is a case in point. Used in "pure direct" mode, the preamp DOES have fully balanced, differential circuitry from input to output. But if not in direct mode, the XLR outputs are still active - but no longer balanced. You are mixing apples and oranges. XLR inputs and outputs on well designed equipmen are ALWAYS balanced. Interior circuitry may or may not be. For example, a preamp may receive an unbalanced signal on an RCA socket or a balanced one on XLR but inky take pin 2 signal. This unbalanced signal will go through all the preamp stages and be converted to fully balanced output at the end, with a phase inverter and balanced line driver. Alternatively, a fully balanced preamp, like ours, can recieve an unbalanced signal on an RCA socket, convert to balanced (see above) and proceed through all the balanced stages of the preamp to the native balanced output. It is a terrible idea to feed an unbalanced signal into a balanced input. In an amplifier, this would result in only 1/4 of the power being available. There coyld be orher unfortunate effects. I am QUITE certain that XSP's balanced outputs are fully functional with bass management. First, it would be a monumental embarrassment to the designer if they weren't. However, I am actually using a bridged stereo amp for XLR/Mono operation from the balanced sub outputs of the preamp with bass management. The way bridging works is the left and right amp channels amplify the hot and cold signals from the balanced signal. This amp has separate left and right power leds. These leds both show equivalent signal being present on both channels i.e the recieved signal has both hot anbalanced.nponents - it's balanced. |
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KeithL
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Post by KeithL on Jan 22, 2020 11:59:51 GMT -5
You are correct about XLR connectors.... An XLR connector offers the three connections required for a balanced connection (two signal lines plus a ground). And, in most equipment, if you have XLR inputs or outputs, they are usually balanced inputs or outputs.
(XLR connectors and cables cost more than their RCA equivalents... and take up more space on the panel... so using XLR connectors for unbalanced connections is usually considered wasteful.) However it is certainly possible to simply use only the in-phase connection pin and leave the other signal pin unused.
- Some vintage equipment, and some microphones, require that the second signal pin be either used or grounded; while some modern gear prefers it to be either used or left floating. - On the XLR-to-RCA adapters we sell the second signal pin is left floating, which is the preferred configuration for most modern gear, including ours. - Also note that we're talking about the standard 3-pin XLR connector... they do also come with four or five pins... and those types are sometimes used for balanced headphone connections.
However, I would still caution about conflating BALANCED CONNECTIONS with BALANCED CIRCUITRY.
A balanced connection refers to a connection between equipment in which there are two signal lines. One carries an in-phase copy of the signal. While the other carries an out-of-phase copy of the signal. (The third pin/line is a ground.)
At the receiving end, the two signals are subtracted, which reinforces the desired signal, while cancelling out any noise common to both lines. (The wires in the cable are usually twisted together - ensuring that most noise that enters the cable past the shielding will be common to both lines - and so will be cancelled out.) THE MAIN BENEFIT OF A BALANCED CONNECTION IS THAT IT IS MORE IMMUNE TO NOISE - ESPECIALLY WITH LONG CABLE RUNS.
Balanced circuitry refers to a situation where the amplifier or preamp actually has two separate signal paths (so two entirely separate preamplifier or amplifier "channels").
The benefit of this is that any distortion that occurs equally in both signal paths will tend to cancel out - resulting in lower overall levels of some types of distortion.
(Not all distortion will cancel out, and background noise may only be somewhat reduced by the cancellation, but there is at least some net gain.) (Also note that, when referring to an amplifier, "fully balanced circuitry" and "fully differential" are more or less equivalent.) THE MAIN BENEFIT OF BALANCED CIRCUITRY IS THAT CERTAIN TYPES OF DISTORTION CANCEL OUT - RESULTING IN SLIGHTLY LOWER OVERALL DISTORTION AND A DIFFERENT DISTORTION SIGNATURE.
However.....
It is important to note that you can have balanced inputs and outputs, and balanced connections, on equipment that does not have balanced internal circuitry. And you can also have an amplifier which does have fully balanced internal circuitry yet lacks balanced inputs (although this is less common). In general, in order for an entire system to be considered "fully balanced", the gear that comprises it should have balanced circuitry and also be connected by balanced connections.
For example: - Our XPA amplifiers have true balanced inputs but do not have fully balanced internal circuitry (they use a single amplifier module per channel). - Our XPA-DR amplifiers have both true balanced inputs and fully balanced internal circuitry (they have balanced inputs and use a balanced pair of amplifier modules per channel). - Our XSP-1 preamp has both true balanced inputs and a fully balanced main signal path (including things like the input selectors and the volume control).
However, certain portions of its internal circuitry, including the crossover filters and the Tone Trims, are not fully balanced.
So you have a choice between a fully balanced "purist mode" and a more full-featured "regular mode" which is internally not "fully balanced".
(In all cases, both the balanced and unbalanced inputs and outputs remain active; internal circuitry converts the signal between balanced and unbalanced when necessary.) (It's also worth noting that, since there is no accepted standard for balanced phono connections, the phono inputs are always unbalanced.)
I think that you're mistaken, dimitryz . I have RCA to XLR (unbalanced to balanced) adaptor cables that work fine. Therefore your statement that "output of an XLR connector is always balanced by definition" must be wrong. I could be mistaken, but I don't think so. I also see numerous preamplifiers, for example, that have XLR inputs and outputs, yet the manufacturers clearly state that the preamps do NOT have balanced circuitry. The Emotiva XSP-1 is a case in point. Used in "pure direct" mode, the preamp DOES have fully balanced, differential circuitry from input to output. But if not in direct mode, the XLR outputs are still active - but no longer balanced. |
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Post by KeithL on Jan 22, 2020 12:28:28 GMT -5
Errr.... just to specifically make one minor correction there...
Even if you engage the Tone Trims on the XSP-1 the output signal is still fully balanced. (However it can no longer be said to have "followed a fully balanced signal path".)
Assuming you start with a balanced input signal.... When you engage the Tone Trims, the balanced signal is converted to an unbalanced signal, modified by the Tone Trims, then converted back into a balanced signal. Therefore the signal appearing at the output is in fact still (again) fully balanced.
And so any connection between the balanced output of the XSP-1 and the balanced input of another device will also be a fully balanced connection. (In fact, even if you start with an unbalanced input, the balanced output of the XSP-1 will still be balanced... after passing through the internal unbalanced-to-balanced conversion circuitry.)
garbulky hit it on the head. The manual says it explicitly. If you have a balanced input, and are using the balanced outputs, then the fully-differential circuitry is maintained throughout the signal path, and the preamp can rightly be said to be "fully balanced." However, if you engage the tone controls, then the XLR full-range outputs still work, but the output signal is no longer fully balanced. Likewise, if you use the bass-management, the XLR outputs and the subwoofer outputs still work, but the output signal is no longer fully balanced. So the XSP-1 can be said to be a "fully-differential, balanced-circuitry preamp" sometimes. But never when the tone controls are engaged or when the bass-management is used. Boom PS: This is not unusual among preamplifier makers. Since the cost of the components doubles when designing completely balanced circuits, it is common to revert to unbalanced mode when using "peripheral" functions such as tone control and bass management to save money. I've never seen a design with balanced tone controls, for example. There may be one, but they're definitely rare. And this statement applies at ALL price levels. I'm currently reviewing an $8,000 preamp that, despite having XLR input and output, is not fully balanced. |
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KeithL
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Post by KeithL on Jan 22, 2020 12:57:08 GMT -5
Yes... the outputs are fully balanced... regardless of whether the signal path is fully balanced... and regardless of whether the input is balanced.
I would add one thing here...... which is quite important when discussing OUR fully balanced amplifier designs (and many other modern designs).
There are actually two slightly different ways in which "balanced amplifiers" are internally configured.
In one configuration, the balanced amplifier consists of two entirely separate halves, each driven by one phase of the input signal. With amplifiers wired this way, if you were to use a passive unbalanced-to-balanced adapter, one half of the amplifier would receive a drive signal, while the other would have no input.
As a result, the half with no input would essentially become "an active ground", which would contribute nothing to the output power available. (And, as dimitryz says, the result would be significantly less power, and none of the benefits of a balanced amplifier.)
HOWEVER, all of our balanced models employ a "fully differential cross connected" design. Each of the two halves of the amplifier has its own fully balanced input - each of which is driven by both phases of the input signal (the connections are simply reversed for the inverting half). So, if one half of the input signal is not present, both halves of the amplifier still receive an input signal, and the full power of both is still available. You also get the distortion cancellation benefits of the balanced design. The only difference is that the gain will be reduced by 6 dB.
I think that you're mistaken, dimitryz . I have RCA to XLR (unbalanced to balanced) adaptor cables that work fine. Therefore your statement that "output of an XLR connector is always balanced by definition" must be wrong. I could be mistaken, but I don't think so. I also see numerous preamplifiers, for example, that have XLR inputs and outputs, yet the manufacturers clearly state that the preamps do NOT have balanced circuitry. The Emotiva XSP-1 is a case in point. Used in "pure direct" mode, the preamp DOES have fully balanced, differential circuitry from input to output. But if not in direct mode, the XLR outputs are still active - but no longer balanced. You are mixing apples and oranges. XLR inputs and outputs on well designed equipmen are ALWAYS balanced. Interior circuitry may or may not be. For example, a preamp may receive an unbalanced signal on an RCA socket or a balanced one on XLR but inky take pin 2 signal. This unbalanced signal will go through all the preamp stages and be converted to fully balanced output at the end, with a phase inverter and balanced line driver. Alternatively, a fully balanced preamp, like ours, can recieve an unbalanced signal on an RCA socket, convert to balanced (see above) and proceed through all the balanced stages of the preamp to the native balanced output. It is a terrible idea to feed an unbalanced signal into a balanced input. In an amplifier, this would result in only 1/4 of the power being available. There coyld be orher unfortunate effects. I am QUITE certain that XSP's balanced outputs are fully functional with bass management. First, it would be a monumental embarrassment to the designer if they weren't. However, I am actually using a bridged stereo amp for XLR/Mono operation from the balanced sub outputs of the preamp with bass management. The way bridging works is the left and right amp channels amplify the hot and cold signals from the balanced signal. This amp has separate left and right power leds. These leds both show equivalent signal being present on both channels i.e the recieved signal has both hot anbalanced.nponents - it's balanced. |
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Post by garbulky on Jan 22, 2020 13:46:21 GMT -5
dimitryz I think what we are trying to say is that the preamp uses fully balanced signal path except in the case of bass management. Emotiva's code for this has been differential reference. They've also called it "Quad differential".
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Post by Boomzilla on Jan 22, 2020 13:49:33 GMT -5
Thanks, Keith - Your comments mostly bolster what I was trying to say, but the balanced to unbalanced, and then back to balanced is new to me. So If I have a DAC, for instance, that has only an unbalanced output - then I feed it to the XSP-1 and I use the XLR outputs of the preamp - the preamp has "split the signal" for me and now outputs truly +/- balanced outputs?
And a further question - If I feed the XSP1 a truly balanced input, but use the unbalanced outputs of the preamp - am I getting the noise reduction benefits at the input? In other words, does the preamp cancel line noise before "converting the signal to unbalanced?"
Boom
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Post by KeithL on Jan 22, 2020 13:51:52 GMT -5
Yes. Thanks, Keith - Your comments mostly bolster what I was trying to say, but the balanced to unbalanced, and then back to balanced is new to me. So If I have a DAC, for instance, that has only an unbalanced output - then I feed it to the XSP-1 and I use the XLR outputs of the preamp - the preamp has "split the signal" for me and now outputs truly +/- balanced outputs? Boom |
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Post by KeithL on Jan 22, 2020 14:36:02 GMT -5
To the first question.... Yes. With an unbalanced input, the input signal is fully "split", resulting in a fully balanced output signal. And, to the second question, also... Yes. The unbalanced output signal is derived by differentially combining the two halves of the balanced signal. The noise cancellation takes place at the point where the conversion occurs. Just to avoid any confusion here....
A balanced audio signal contains two copies of the same signal - one of which is 180 degrees out of phase with the other. When these two signals are connected to the two inputs of a "differential input".... The "out of phase signal" is subtracted from the "in phase signal" resulting in an in phase signal (actually at 2x the amplitude). The "out of phase noise" is subtracted from the "in phase noise" and, since the two are pretty much the same, the result is that the noise is cancelled out. However, the process involved could be described as "summing" the two or as "subtracting" them, depending on your point of view.
Also note that a balanced connection cancels out "common mode noise"... which means noise that is common to both signal lines (which includes most noise from outside the line). And, if, for whatever reason, the source imposes noise or hum identically on both output lines, this too may be cancelled.
However, hiss generated by the individual output line drivers is random, and so will not cancel between the two lines. (The signal level is doubled, while the hiss is more averaged, so there may be some reduction in source hiss, but only a few dB at most.)
Thanks, Keith - Your comments mostly bolster what I was trying to say, but the balanced to unbalanced, and then back to balanced is new to me. So If I have a DAC, for instance, that has only an unbalanced output - then I feed it to the XSP-1 and I use the XLR outputs of the preamp - the preamp has "split the signal" for me and now outputs truly +/- balanced outputs? And a further question - If I feed the XSP1 a truly balanced input, but use the unbalanced outputs of the preamp - am I getting the noise reduction benefits at the input? In other words, does the preamp cancel line noise before "converting the signal to unbalanced?" Boom |
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Post by Gary Cook on Jan 22, 2020 15:03:27 GMT -5
This type of question come up a lot (a simple balanced output versus fully balanced discrete differential circuitry) and if I may be so bold as to make a suggestion, KeithL I think a simple drawing of the signal path would be useful in explaining the differences. Not a detailed circuit but just a very basic schematic. That way it can be copied whenever the question pops up. Explanations in words are always long winded and people’s understanding of the exact meaning can be quite different. Cheers Gary |
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