It is balanced or not?


Hello everyone, I am new to this page, I thank the Audiogon team for allowing me to be here with you, I have a question: I have the preamp and DAC: "Emotiva Differential Reference XDA-1" it has the following digital inputs: "S/PDIF (optical and coaxial) and AES/EBU (XLR)", the XDA-1 has balanced outputs for an speakers amplifier, inside it has the amplifier: "Texas Instruments Burr Brown OPA2134" and I want to know if it really works balanced; the XDA-1 has the DAC: "Analog Devices AD1955" inside. thanks
joser9616
Sounds like an Atmasphere question to me...
Sorry, OP, but I am not an expert on wiring, but Ralph would be one of the people who give you the correct answer.
Bob
Ok, thanks, I'm new here, who's Ralph? lol, thank you very much :-)
AD1955 has differential current output (two current output pins).  In order to make differential voltage output (balanced output) it needs two current to voltage converters.  OPA2134, being very low bias current dual amp, is good candidate for that.
I read that from Burr Brown OPA2134 in its specs. but I did not understand very well, so I was in doubt that if that could mean if it was balanced, thank you very much for getting me out of doubt.
Op amps are not balanced when a single op amp is used.

They can be used to output a balanced signal by either outputting to a transformer os using two opamp sections.


joser9616,  you're welcome.  OPA2134 has also high current drive ability making it a good choice for an output amp (combined function of I/V converter and output driver). 
I have the Emotiva conected to a 2 mono Crown D-75 balanced.
erik_squires the Emotiva Differential Reference DAC XDA-1 have two of the OPA2134PA
After working on and rebuilding an XDA-2 DAC and looking at the XDA-1, my only answer would be "maybe?".  I see two 2134 op amps after the fully differential AD1955 DAC chip.  This suggests that the opa2134 op amps are working in fully balanced differential mode for the I/V section.  After that, it goes straight to the discrete analog output stage.  It is difficult to tell if this discrete analog stage is fully differential/balanced, but I would only assume so.

This is different than the XDA-2 dac, which has the same two opa2134 I/V op amps, but then goes through another single opa2134 op amp which acts as a low-pass filter and downgrades this to "single-ended".  Then the XLR outputs have their own set of opa2134 which convert the single-ended analog back to differential.  The XDA-2 is not "fully differential" from end-to-end, but the XDA-1 DAC might be.
@joser9616  There is an easy way to tell if you have a DVM (Digital Volt Meter). If you don't the best way to find out is to talk the manufacturer.
@joser,
That was Ralph (Atmasphere).
B
I just checked....it is differentially balanced according to their site...(but are your amps)
Than you very much to all!!!!! thank you than you :-) yes stringreen, the Crown D-75 and Crown D-75A are balanced, they are studio amplifiers(pro) oh ok gdnrbob.
@joser9616 - One point.   Just because they are "studio amplifiers" does not mean they are fully balanced.  The analog input stage of the amp may be balanced, but the amplifier itself is single-ended.  You can tell because the amp can be bridged-mono to double the power output.   You would not be able to do this on a balanced/differential amplifier.

In actuality, pretty much all studio equipment is not fully balanced.  "XLR balanced" was developed as a way to transfer analog signals between equipment devices, sometimes a very long distance (50-100+ feet).  In almost all cases I have seen, the XLR input on a studio equipment will always convert to single-ended analog internally for purposes of volume / equalizer / mixing / etc.  Then, on the output, it will convert back to "balanced XLR".
wow!!! thanks, very informative, thank you
Please people, which of these two amps have better audio quality? thanks: 
http://www.ti.com/product/MC33078
it is inside a JBL Professional MSC1Studio Monitors Controller
 http://www.ti.com/product/OPA2134
it is inside of a Emotiva DAC Preamp XDA-1 thanks.
The op amp is a factor in sound quality, but it's never the full story.  You also need to look at power supply, etc.   The fact that the JBL uses a switching wal-wart power supply is an indicator of poor sound quality.  The JBL is meant as a cheap mixer / room correction unit.  I believe the Emotiva would have highly superior sound quality, especially since it has a fully discrete output stage.
Ok, thank you very much, but if I connect the Emotiva to the JBL MSC1?, The Emotiva is digital and it has unbalance and balance output, I want to connect that output to the JBL MSC1, what do you think?
...well is gonna be the same.
@auxinput I do not understand why it can not be balanced by having a mono and bridge option, it is very rare, that amplifier has been used for many years in professional studios and has even been described as almost high-end. Did you see any diagram of that amplifier to know those details?
@auxinput I fond it here: http://bee.mif.pg.gda.pl/ciasteczkowypotwor/SM_scena/Crown/D75%20Service%20Manual%20%20-1.pdf it is just as you were saying, but please tell me, it is better to use it as a stereo then? thanks.
Running the sound through the JBL MSC1 is definitely going to degrade the sound quality of the Emotiva DAC, but if that's all you have, that's what you are gonna have to use. 

Is the amp better to use as stereo?  Generally speaking, yes.  It really depends on the speakers and if they drop below 8 ohms, but usually stereo amps do not perform as well in bridged mode.

Generally, a dedicated balanced/differential amp will have power from both the +(RED) and -(BLACK) speaker posts.  In this situation, you cannot bridge amp channels because they are already, in a sense, bridged. 

The service manual does not give a complete schematic, but if you look at page 6-3, you can see the Output Stage schematic.  On the right side of the schematic you can see the output connected to one speaker binding post.  The other speaker binding post is shunted directly to ground, so this is a single ended amp (even though the input stage is balanced).
Too many sources and amps are really SE main circuitry with opamps on the input or output to make them pseudo balanced (xlr) just to suck in the xlr freaks.

In these cases stick with SE, and you bypass these opamps (best opamp is no opamp). You only need balanced (xlr) if your running 10mts of interconnect through bad surroundings with lots of rf emitting equipment.
Cheers George
@auxinput: Well, I think the best way that the Crown D-75 can sound is in stereo, because each amplifier has its connection balanced or unbalanced and is not divided for 2 amps, as it is on page 6-1 of the service manual; in My opinion, the best way they can sound is to put them both in stereo and connect the right speaker on channel 2 of one of them and the left speaker on channel 1 on the other, both in stereo, so each internal amp has its conection. what did you think? thanks :-) 
yeah, that sounds like a good plan.  If you have two D-75 amps, use one for left speaker and use the other amp for right speaker.  That way, you are not sharing a single amp power supply for both speakers.
@auxinput: yes, but not in mono, in dual channel but using one of the amps for a speaker :-)
Right.  If you have two D-75 amps, it is better to use one amp per speaker.  But not in bridged mode.  The power supply from one amp is only used to power one speaker.  This is better because a single amp power supply does not have to push two speakers.  You will get better results.
That's right, thank you very much for your help and the others here in this forum, the change was quite remarkable, much more sound quality.
@auxinput Hi, I think I have something better than the Emotiva in my house and I did not know it, it's the Roland Mobile UA, it's a USB Audio Interface for headphones and it can also be used balanced to studio monitors: https://www.roland.com/global/products/mobile_ua/, it has this inside, amps:http://www.ti.com/product/TPA6120A2/description, DAC:https://www.akm.com/akm/en/product/datasheet1/?partno=AK4414EQ, and I think this works as pre amps: http://www.ti.com/lit/ds/sbos484a/sbos484a.pdf 
did you think this is better? thanks.
No, not likely better than Emotiva DAC.
Ok, but why?, it has a better hardware...
@auxinput Hello, I'll be extremely honest, the Roland Mobile UA sounds a lot more detailed, with all types of music, Jazz, Rock, Classical Rock, Classical music, everything sounds better, it's a bit more on the treble side, but not in a way that offends or dislikes. congrats to all the fathers, have a good day.
The Texas Instruments OPA1642 works as Low Pass Filter FET-input opamps and it is used in high end receivers and the Texas Instruments TPA6120A2 works as Output buffers and they are high fidelity amps used in high end USB interfaces for headphones, it works balanced and you can conect it to an amp, believe me, more detailed sound.