[KeithEmo]

  Hi guys, I currently have a DC-1 and love the little thing. Before I go on, please forgive my readily apparent naivety.
I also own a pair of Hifiman's HE-400is which I usually power through the single-ended outputs at the front of the unit as you're supposed to. I recently learned that the Hifimans (I think) can be run in balanced mode. So I got to thinking, rather than using the single ended outputs, can I hook up the Hifimans to the DC-1 in balanced mode where the 'phones would be fed from the XLR outputs at the back for example?
   Please let me know if what I suggest is disastrous or dangerous in any way

 

 
You won't risk damaging anything by connecting your HiFiMan 400's to the balanced outputs on the DC-1. Unfortunately, however, I don't think you're going to be especially pleased with the results.
 
The reason is that the balanced outputs of the DC-1 are really line level outputs and aren't intended to drive headphones. Because your HE-400's are relatively high-efficiency for planars, they will probably work on the balanced outputs, but it's doubtful that the balanced outputs will be able to drive them to very loud listening levels. Beyond even that, since the balanced outputs aren't intended to drive headphones directly, they have a relatively high output impedance (which means you will have very little damping, and the interaction between the outputs and the headphones may well add some odd colorations to the sound as well). On the DC-1, you're really better off using the front panel headphone outputs (which go through output buffers specifically designed to drive headphones).
 
You also need to understand that all headphones are internally "balanced" (each ear has a speaker - which is an inherently balanced device). The reason your HiFiMan's "can be wired as balanced" is simply that you can get to both wires coming from each ear speaker. However, since each speaker is a "floating two-wire device", there is no specific benefit in using balanced wiring in and of itself. (Any benefit you get by "using them balanced" would be because the amplifier you're using works or sounds better when used that way.) Therefore, with the DC-1, using the (proper) headphone output on the front panel is going to give you much more benefit that using the (line level) outputs simply because they're balanced.

 

[ashutoshp]

  You also need to understand that all headphones are internally "balanced" (each ear has a speaker - which is an inherently balanced device). The reason your HiFiMan's "can be wired as balanced" is simply that you can get to both wires coming from each ear speaker. However, since each speaker is a "floating two-wire device", there is no specific benefit in using balanced wiring in and of itself. (Any benefit you get by "using them balanced" would be because the amplifier you're using works or sounds better when used that way.) Therefore, with the DC-1, using the (proper) headphone output on the front panel is going to give you much more benefit that using the (line level) outputs simply because they're balanced.

This is GOLD Keith. I am a grown man but I am not afraid to say this- I love Emotiva! I get gooey eyed when I see the DC-1 on my media center every morning and the proudest day of my audiohead life was when my 6-year old said this- "daddy, can I listen to some Lego Chima music on the DC-1 DAC".
 
    Seriously though, am I correct in my interpretation that all the balanced output is doing is that its providing more power and hence higher volume which can be perceived as 'better' sound?
    Another question, the Hifiman cables that come with the HE-400i are TRRS (I think). Are they inherently balanced (if i've interpreted the Rane guide to interconnects carefully?   

 

[KeithEmo]

  This is GOLD Keith. I am a grown man but I am not afraid to say this- I love Emotiva! I get gooey eyed when I see the DC-1 on my media center every morning and the proudest day of my audiohead life was when my 6-year old said this- "daddy, can I listen to some Lego Chima music on the DC-1 DAC".
 
    Seriously though, am I correct in my interpretation that all the balanced output is doing is that its providing more power and hence higher volume which can be perceived as 'better' sound?
    Another question, the Hifiman cables that come with the HE-400i are TRRS (I think). Are they inherently balanced (if i've interpreted the Rane guide to interconnects carefully?   

 
It's a bit more complicated than that.
 
With line level SIGNALS (like between a preamp and an amplifier), a balanced connection is more resistant to picking up noise - like hum. With balanced CIRCUITRY, there are possible benefits in terms of distortion. (All amplifiers produce some distortion. In a balanced amplifier, the distortion produced by the two "halves" cancels out, leaving you with less overall distortion. Note that this benefit is theoretical; you may or may not actually get it depending on the actual design.)
 
In the case of headphones, the "real" logic is more like this......
 
A balanced amplifier can (and often will) produce lower distortion than a single ended amplifier. This happens to be especially true for headphone amplifiers, many of which tend to more exotic designs that use very little feedback, and have other special characteristics that make them more likely to benefit from a balanced topology than most speaker amps.
 
Like speakers, virtually all headphones are internally "inherently balanced" - each ear speaker has two wires - a (+) and a (-) wire. In most headphone cables, the two (-) terminals are connected together, and connected to the single ground lead in the cable. This works fine with an unbalanced amplifier, which also uses the same ground for both channels. And the ONLY thing preventing you from connecting a particular pair of headphones to a balanced amplifier is that they weren't wired for a balanced connection. With a balanced amplifier, you CANNOT connect the two grounds together; you MUST have four separate wires, with separate right(+), right(-), left(+), and left(-) wires connecting to the headphones.
 
Therefore, if you want to use a balanced amplifier with your headphones, then your headphones must have removable wires, and/or must not be wired with a common internal ground. (Since the HiFiMan's use a separate two-wire connector for each ear, it's relatively easy to make up a cable with four separate wires that meets this requirement.)
 
In the case of the DC-1, NEITHER of the line level outputs is designed to drive headphones. The headphone outputs on the DC-1 use special high-power low-impedance buffer drivers, which do an excellent job of driving headphones. Both the balanced and unbalanced outputs on the back are designed to send line-level signals to other components, and simply aren't as good as headphone amplifiers. Therefore, on the DC-1, the headphone outputs on the front will sound better driving headphones (not because they're unbalanced - but because they were designed to drive headphones). Therefore, if you're connecting headphones to the DC-1, you want to use the headphone outputs (and not the line outputs).
 
As long as the connectors are wired correctly (or you use the correct adapter), you can use headphones that have either "balanced" or "unbalanced" wiring, but I wouldn't expect to hear any difference between them.
 
 

 

[northshore]

I like the way Keith is able to explain things in an easy to understand manner from his very knowledgeable foundation.
 
The preamp outputs on the DC-1 back do have variable output and that may have caused the confusion. Although they are separate from the amplifier section designed to drive headphones, they are versatile within their designed function and those balanced outputs will drive components that require even the higher signal of a ‘pro amplifier’.
 
I happily use the un-balanced outputs with a balanced amp. The DC-1 is a great source that scales well when ready to try that topology with the HE-440i.             

 

[ashutoshp]

  I like the way Keith is able to explain things in an easy to understand manner from his very knowledgeable foundation.
 
The preamp outputs on the DC-1 back do have variable output and that may have caused the confusion. Although they are separate from the amplifier section designed to drive headphones, they are versatile within their designed function and those balanced outputs will drive components that require even the higher signal of a ‘pro amplifier’.
 
I happily use the un-balanced outputs with a balanced amp. The DC-1 is a great source that scales well when ready to try that topology with the HE-440i.             

+1 to that. I have been reading Keith's posts over in the DAC side of things as well and on Emotiva's own forum. Good stuff. Thank you.
I hope you keep it up Keith. Patience is a virtue with these endeavours which is NEVER easy to come by, leave alone sustain.  I know I need clarity to see through the fuzziness out there. 
I looked up some balanced amps for headphones and they seemed quite pricey as some others also noted in response to my original query. I could be wrong but balanced anything seems to demand a premium when it comes to audiophiles

.    

 

[money4me247]

correct me if I am wrong, but I think the purpose of the balanced outputs is to run the emotiva as a balanced dac to a balanced amplifier. so that is what you would use those outputs for.

 

[Sal1950]

Just wanted to mention I've had my DC-1 for a little over a week now and am completely in love with it!
I've experienced no issues with noise, humming or buzzing as others have mentioned here in any way.
Running a quad core gigabyte based computer with PCLinuxOS Linux installed and using the Clementine media player set up to deliver a completely bit perfect data stream to the DC-1.
My music collection includes CD's I've owned for 30 years and LP's that I've owned much longer and digitized using Audacity. I hate to repeat this often used rave, but I really am hearing things in these recordings that I've never heard before.
Recordings allowing, the sound is so smooth and warm sounding I can't help listening to album after album, staying up very late every night just to hear what this or that recording sounds like with the DC-1.
The only thing I can take issue with is that the unit seems to run a bit hot. Even when shut off to the standby state the case is very warm. For now I'm turning off the main power switch when not in use, I don't like subjecting the components to these high temps 24/7. Think I'm going to build a support of some type that will include a small cooling fan to keep the unit down to more reasonable temps.
Thanks Emotiva for giving us such a large bang for the buck digital component!

 

[ashutoshp]

  The only thing I can take issue with is that the unit seems to run a bit hot. Even when shut off to the standby state the case is very warm. For now I'm turning off the main power switch when not in use, I don't like subjecting the components to these high temps 24/7. Think I'm going to build a support of some type that will include a small cooling fan to keep the unit down to more reasonable temps.

@Sal1950 I had the same issue originally. In fact, I remember a mild panic when i could smell plastic burning when I bought it initially.
IIRC, after reading some of Keith's posts over on the Emotiva forum, I realized that in fact, this is normal behaviour and one should be worried if it does not heat up. I've seen figures of >100F quoted!!   
   As poor as I am in distinguishing between non-transducer related components in an audio chain, i can tell you this much- I will never listen to 'cold' equipment again. The DC-1 is downright brittle when switched on from the back. I highly recommend warming it up a good 15 minutes or so before starting to listen. In fact, I don't switch it off anymore, as much as it pains me. The same goes for my powered monitors as well. YMMV 
 
@money4me247 you're right about the balanced connections. I was thinking of putting in a resistor box in between the balanced line out and the headphones but wanted to get some idea before spending any money. I've spent way too much money trying to forge a shortcut only to realize later on that they will never really work 

..... but when they do, I feel like that dude who cried 'eureka' while naked in his bathtub!! 

 

[KeithEmo]

  @Sal1950 I had the same issue originally. In fact, I remember a mild panic when i could smell plastic burning when I bought it initially.
IIRC, after reading some of Keith's posts over on the Emotiva forum, I realized that in fact, this is normal behaviour and one should be worried if it does not heat up. I've seen figures of >100F quoted!!   
   As poor as I am in distinguishing between non-transducer related components in an audio chain, i can tell you this much- I will never listen to 'cold' equipment again. The DC-1 is downright brittle when switched on from the back. I highly recommend warming it up a good 15 minutes or so before starting to listen. In fact, I don't switch it off anymore, as much as it pains me. The same goes for my powered monitors as well. YMMV 
 
@money4me247 you're right about the balanced connections. I was thinking of putting in a resistor box in between the balanced line out and the headphones but wanted to get some idea before spending any money. I've spent way too much money trying to forge a shortcut only to realize later on that they will never really work 

..... but when they do, I feel like that dude who cried 'eureka' while naked in his bathtub!! 

 
You do always have to keep temperature figures in perspective... in general, 135 degrees Fahrenheit is considered to be "hot enough to hurt a little when you touch it" - but still is not going to cause a blister or burn, and our body temperature is right around 99F (so 100F isn't really very warm at all). The DC-1 burns around 15 watts, and so will run somewhat warm to the touch, most of that heat coming from the linear regulators in the power supply. It does have vents on the top, which you shouldn't block, but other than that I wouldn't worry about it.
 
Putting a resistor between an output and headphones is somewhat problematic. Most people consider it to be important that the output on a headphone amplifier have a low impedance to provide damping to the headphone, and to avoid interactions between the amplifier and the impedance of the headphone that can cause significant frequency response variations. Since this isn't a factor with line level outputs, many line level outputs already include a series resistor - just to protect themselves from output short circuits. Adding another resistor (or putting one there if there wasn't already one there) basically raises the output impedance to the value of the total series resistance. (So, if there was no resistor there to begin with, and you add a 220 ohm resistor, then you have made the output impedance 220 ohms.)  Since "the ideal headphone amp" should have an output impedance of a few ohms or lower - with zero being the theoretical ideal - this makes for a far from ideal situation. (In reality, some headphones will still work well and sound fine if you do this, but with others it will affect the frequency response, and even how clean the bass sounds, possibly to a significant degree. So, in general, if something has a decent headphone amp built in, you're better off using it.)

 

[Sal1950]

   
You do always have to keep temperature figures in perspective... in general, 135 degrees Fahrenheit is considered to be "hot enough to hurt a little when you touch it" - but still is not going to cause a blister or burn, and our body temperature is right around 99F (so 100F isn't really very warm at all). The DC-1 burns around 15 watts, and so will run somewhat warm to the touch, most of that heat coming from the linear regulators in the power supply. It does have vents on the top, which you shouldn't block, but other than that I wouldn't worry about it

 
Thanks for the response Keith and ashutoshp!
I'm sure the unit is running well inside it's design parameters and that it's temperature levels are safe.  It is only my position that any heat that can be reduced will only have the effect of extending the life of the components involved. I run about 7 fans inside the CM Cosmos case to keep things cool in there. It might be worth mentioning that I live in Central Florida and run a minimal amount of air conditioning. Inside temps here normally run right at 82 degrees..
Salute,
Sal

 

[ashutoshp]

   
Thanks for the response Keith and ashutoshp!
I'm sure the unit is running well inside it's design parameters and that it's temperature levels are safe.  It is only my position that any heat that can be reduced will only have the effect of extending the life of the components involved. I run about 7 fans inside the CM Cosmos case to keep things cool in there. It might be worth mentioning that I live in Central Florida and run a minimal amount of air conditioning. Inside temps here normally run right at 82 degrees..
Salute,
Sal

Makes sense. I'm in PA so things are slightly colder. Maybe Emo should start adding the space heater/hand warmer on its DC-1 features list. 

 

[northshore]

  correct me if I am wrong, but I think the purpose of the balanced outputs is to run the emotiva as a balanced dac to a balanced amplifier. so that is what you would use those outputs for.

Not to correct you, as I would like to hear what Keith has to say on this issue - but balanced outputs were used in the pro audio world long before balanced headphone amplifiers existed. Craig at Eddie Current used to have a white paper entitled, “To Balance or not to Balance” but looks like the link no longer works. It helped to dispel many of the balanced headphone amplifier myths. 

 

[ashutoshp]

True

  Not to correct you, as I would like to hear what Keith has to say on this issue - but balanced outputs were used in the pro audio world long before balanced headphone amplifiers existed. Craig at Eddie Current used to have a white paper entitled, “To Balance or not to Balance” but looks like the link no longer works. It helped to dispel many of the balanced headphone amplifier myths. 

I agree and second your mythbuster request. I too dont understand how it changes sound except for the fact that they provide more voltage swing and lower (audible?) distortion.  
 
Just thought I'd add a little more. IIRC, most (good) USB audio recording interfaces these days (>$75-100 exc. Behringer) seem to have balanced outs.
As well, connecting a balanced out to an unbalanced input is still possible with transformer boxes like the ones made by Jensen and JDI Radial, although the good ones aren't cheap. JDI radial in fact makes this little box called H-amp which is supposed to slot in between monitors/amps outputs and headphones, although I get lost in the details and end up throwing my hands up in disgust for not paying attention during my physics class.    

 

[greenkiwi]

  True
I agree and second your mythbuster request. I too dont understand how it changes sound except for the fact that they provide more voltage swing and lower (audible?) distortion.  
 
Just thought I'd add a little more. IIRC, most (good) USB audio recording interfaces these days (>$75-100 exc. Behringer) seem to have balanced outs.
As well, connecting a balanced out to an unbalanced input is still possible with transformer boxes like the ones made by Jensen and JDI Radial, although the good ones aren't cheap. JDI radial in fact makes this little box called H-amp which is supposed to slot in between monitors/amps outputs and headphones, although I get lost in the details and end up throwing my hands up in disgust for not paying attention during my physics class.    

I'd love to see this too.  I often think that it ends up being a case where people put more money into the balanced amp and it ends up sounding better.  To me it seems more like a zero sum game.  If you have $X to spend on materials in an amp, it feels like you should be able to design a SE that is as good or better than the balanced.
 
I'd really love to see a double blind test on this.

 

[m002d2]

Every time I get an email notification that someone's added to this DC-1 thread I get excited because I always like to hear what Keith has to say. I'm using the DC-1 as my desktop computer system with JBL LSR305's and the LSR310S sub. I have nothing to add but to say that I've owned some pretty expensive systems and this one is easily my favorite. The imaging is what kicks my ass every time. These speakers with their wave guides and the Stealth ..just wow. It might not get as loud as a Klipschorn or have the chest thump of a set of stacked Advents pumping 1500 wpc, but it's perfect for what I need as an audio system in this room.
 
I also never turn my systems off. These machines have been on since I put them together about 10 months ago. My dad the HAM radio operator always told me that the thermal damage from cycling electronics was far worse than leaving them on 24/7. This was 50 years ago, and it's never done me wrong.