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Sennheiser HD650 Impressions Thread - Page 949

post #14221 of 18280
Quote:
Originally Posted by upstateguy View Post
 

Does this represent anything more than a single isolated case? 

Is the small difference shown audible?

Amps used?  Two different amps or single amp with both functions?

Same headphones but with different cables or two different headphones?

Single trial or 10 trials? 

What controls were used?

Does HeadRoom sell balanced cables?

 

I think the two frequency responses are very close.  Though, usually the balanced amps are superior. e.g.  Schiit Mjolnir vs Asgard

I don't think only balanced cables can make audible difference.

post #14222 of 18280

Saying people would have switched to balanced setups a long time ago if it had any merit is a little unfair. Balanced rigs are expensive, there usually is a recable associated with that, and obviously sometimes with the nature of head-fi, a balanced amp may not be the current "flavor of the week" here. The XLR has a history of being used for long runs of cables since the 3rd pin is connected to a shielded jacket which grounds any RFI the jacket picks up, dual XLR's both having their own ground and the shield. So you could run longer lengths before losing signal to noise from interference. XLR's have been selected in the headphone industry just because thats really one of the more simple plug options where each channel has it's own ground. The 4-pin is becoming more popular as the dual 3-pin is becoming somewhat obsolete if you're not shielding a mere 6ft cable haha.

 

Quote:

Originally Posted by pdrm360 View Post
 

 

I think the two frequency responses are very close.  Though, usually the balanced amps are superior. e.g.  Schiit Mjolnir vs Asgard

I don't think only balanced cables can make audible difference.

 

You pay good money for that last 2% in this hobby. You cannot judge balanced vs unbalanced coming out of the same amp. By plugging it into the unbalanced section in some amps, they're using a coupling circuit which joins the two separate channels together anyway so it's fundamentally different than say, a true balanced topology which is separate from the power section to the output section.

 

Quote:

Originally Posted by upstateguy View Post
 

Does this represent anything more than a single isolated case? 

Is the small difference shown audible?

Amps used?  Two different amps or single amp with both functions?

Same headphones but with different cables or two different headphones?

Single trial or 10 trials? 

What controls were used?

Does HeadRoom sell balanced cables?

 

 

Headroom has sold Cardas balanced cables for some time. Headroom has a fantastic return policy so I think if the whole balanced thing was smoke and mirrors, they would have taken a lot of returns back in the day. They are the ones to bring it to the light.

 

The difference in balanced is not at the cable alone, but the topology of the DAC and amp as well you are right.

post #14223 of 18280

Put me in the camp of Balanced is Mythology for audio consumers.

 

It makes sense in music production, as you're trying to reduce/eliminate noise in a very noisy, potentially, electronic environment.  It is very important for microphone/analog/acoustic recordings of voice and acoustic instruments when you're looking for fine detail against a silky, quiet dark background.

 

For consumption..... not so much. :)

post #14224 of 18280
Donald North over at http://www.dnaudio.com has a great right up of why his amps have a balanced connection output but no balanced input. It has little do to with interference.

Now can we put this topic to rest.
post #14225 of 18280
Quote:
Originally Posted by Anavel0 View Post

<snip>

Now can we put this topic to rest.

 

As long as we realize that the most vocal advocators promote balanced topology because they have something they want to sell.  

 

Another way to put it might be that since there has been no data accumulated over the past 30 years (that I've ever seen) that suggests a balanced topology is audibly different from single ended, the only motivation to promote balanced over single ended would be monetary.

 

And Chris, if balanced was audibly different from single ended, in the way stereo is audibly different from mono,  everything from the least expensive DIY mint amp to the expensive McIntosh would, by default, be balanced. 

 

After 30 years of investigation, the Truth is that balanced doesn't sound any different than single ended.

 

 

 

But first a comment by Steve Eddy: (2-13-11)  http://www.head-fi.org/t/539458/why-balanced-headphone-amps

100x100px-LS-18c496e6_headfiavatar2.jpeg

 

Quote:

Originally Posted by sbradley02 View Post

 

Certain aspects make sense. Balanced inputs have proven noise rejection advantages hence their widespread adoption in pro audio. Having separate ground runs for the left and right cans makes a certain amount of sense, removing resistance from the common ground connection would seem to have advantages though whether it is worth the hassle of rewiring is less clear.

 

Be aware that a fair number of "balanced" headphone amps are just a pair of single-ended amplifiers bridged together in push-pull. This configuration doesn't offer any common-mode rejection.

 

Quote:
Having separate ground runs for the left and right cans makes a certain amount of sense, removing resistance from the common ground connection would seem to have advantages though whether it is worth the hassle of rewiring is less clear.

 

The crosstalk from the common ground contact in a TRS plug/jack can be significant. However it can be largely ameliorated without going balanced. Simply use a four pin connector and tie the grounds together internally in star ground fashion.

 

 

Quote:
Anyone seen a valid technical reason for this?

 

Guess it depends on how you define a "valid technical reason." Greater slew rate is the most common claim, but I don't consider it terribly meaningful as it's rather trivially easy to design a single-ended amp that doesn't slew limit.

 

se

 

 

 

 

100x100px-LS-eb0696e6_bosco-1.jpeg  From kwkarth on the same day: http://www.head-fi.org/t/539458/why-balanced-headphone-amps

 

Someplace around here at least a year or more ago, I posted the genesis of balanced headphone amplifiers.  It was a brilliant business decision, allowing the company create a new product of higher performance from bridging the outputs from amplifier modules already on hand in stock without having to completely redesign.  If I can find it, I will provide a link.

 

 

and KWKARTH went on to say: http://www.head-fi.org/t/539458/why-balanced-headphone-amps

 

Yes, I think this thing took on a life of it's own and pretty soon companies started to realize they could sell more gear at higher profits if they made the gear "balanced."

 

If I'm running 400' of cable from one studio to another, I want a balanced line, but to go from DAC to headamp 1m away, it's a wasted effort, and doubly so if I'm driving an unbalanced device like a speaker or headphone.

 

Now from Elias Gwinn of BenchMark:    http://www.head-fi.org/t/576339/balanced-vs-single-ended-poll

 

My name is Elias Gwinn, I'm an engineer at Benchmark Media Systems.

We've been getting a lot of questions lately about balanced headphones. We are interested in the debate, but I can't say we agree with any technical explanations about the benefits of the set up.

So far, there are 4 major points mentioned so far (that I have heard, at least):

1. Unshared common conductor reduces crosstalk

2. Two amps (per channel) increases slew-rate

3. Two amps provide better damping

4. Balanced cabling provides better common-mode rejection

If I may, I'd like to add my thoughts on these points:

1. Most headphones (at least those of decent quality) do not share a common conductor through the length of the cable (as opposed to what was said in 6 Moons). Most headphones have a separate wire from each negative terminal that remain isolated through the length of the cable. In other words, most headphone cables are effectively balanced inherently. If they were sharing a common through the length of the cable, the impedance of the cable may cause some of the signal to show up on opposing channels. However, they are not connected until the plug, and therefore have a minimal impedance to ground.

2. Any headphone amp that is struggling with slew-rate is a poorly designed headphone amplifier. The HPA2 headphone amplifier on the DAC1 has a bandwidth of 55 kHz, and it doesn't even approach any slew-rate limitations even at those high frequencies.

3. Two amps provide WORSE damping. This is why power amplifiers run better in normal mode vs. bridged mode. A balanced (dual-active) headphone amplifier is exactly analogous to a bridged amplifier driving one speaker. The only advantage is increased power, but it comes at an expense of increased distortion, decreased damping, and altered frequency response. This is common knowledge for bridged amplifiers.

4. Headphones don't need any help with common-mode rejection because they inherently will not respond to common mode signal. If, for example, you apply a signal to both terminals of a speaker, it will not move at all. A speaker only responds to differential voltages.

5. There is another cost incurred by dual-active headphone amps that is not addressed. Headphone amps should have as low of a source impedance as possible. If you are using two amps to drive a channel, you are doubling the source impedance. This will cause the headphones to suffer in frequency response, distortion, and ringing.

Please continue the great discussions. It is important to resolve these debates so that product manufactures can respond to provide the best audio solutions possible.

Thanks!
Elias Gwinn

 

and further from Mr. Gwinn:

 

Second response to similar query: (in same post)
 
ALL headphones have non-linear mechanical impedances (that is, the mass and shape of a speaker will resonate more at certain frequencies and much less at other frequencies). This means the physical build of the headphones (as well as other physical impedances, like your head and ears!) will try to override the electrical system (amplifier and speaker coil).

To create low-distortion headphone response, one must consider 'damping factor'. A high damping factor will control the response of the speaker, thus preventing the physical impedances from dictating frequency response. Damping factor is the ratio of speaker (load) impedance to amplifier (source) impedance. In other words, the best damping factor will result from a low source impedance. Again, the source impedance from the HPA2 is less then 0.01 ohms...as low as gets!!

Balanced headphone amps will double the source impedance of an unbalanced headphone amp. No matter how low the impedance of a balanced headphone amp, it could be half that much if it was unbalanced. This is one reason balanced headphone amps are not a good idea. (It should also be noted that the balanced output of the DAC1 / USB / PRE is 60 ohms or greater, depending on the attenuator settings).

Not only will the source impedance double with balanced headphone amplifiers, but the total distortion and noise of the amplifier will double as well!! Every output device (opamp, transistor, tube) creates some distortion and some noise. If there are two opamps or transistors or tubes driving each headphone speaker, twice as much distortion and noise will be added!!

The result of balanced headphones is less damping factor, more distortion, and more noise. Also, balanced headphones configurations offer no real benefits, to boot.

Feel free to use the XLR outputs of the DAC1 / USB / PRE for balanced headphone outputs (as mentioned above, the DAC1 USB and DAC1 PRE will do better then the DAC1 at this task, because of the 4562's). It won't damage anything to operate in this configuration. But, for the reasons above, I don't recommend it.

Thanks,
Elias

 

 

THE ALTERNATIVE IS TO SAY

 


Edited by upstateguy - 11/4/13 at 6:22am
post #14226 of 18280
Nice compilation.
post #14227 of 18280
Bravo! Can we get that all in a sticky at the top of the amp forums, lol.
post #14228 of 18280

Okay NOW we can put it to rest. B)

 

It's all good, I've heard of the joys of pure class A single-ended triode tube amp designs for decades, and it'd be fun some day to hear same, just not for $3k!  I'm sure there's some nice, third-harmonic distortion introduced by same that adds a glowy warmth to the sound, assuming you can get it to drive hard enough (used to be SET tubes had barely enough amplification for anything other than delicately-plucked lute solo performances.....).

post #14229 of 18280

I am fortunate enough to own a number of combinations suitable for running the HD650

Bel canto usb link to full differential balanced Yulong D18 to Violectric HPA V181 to ZombieX SPC balanced cable to HD650

Bel canto usb link to Yulong D18 single ended output to La Figaro 332S to Moon audio silver dragon xlr to trs adapter to ZombieX SPC balanced cable to HD650

Woo WA7 to Moon audio silver dragon xlr to trs adapter to ZombieX SPC balanced cable to HD650

Ipod classic to CLAS to Fireye HD to trs to trs adapter to Moon audio silver dragon xlr to trs adapter to ZombieX SPC balanced cable to HD650

Design ranges from differential balanced to OTL tubes to Transformer coupled tubes to tricked up Cmoy

All have advantages and shortcomings none are perfect but all are worthy of their place in my collection

In terms of difference I think it is more a question of flavour than better or worse

I really do not understand this balanced bashing crusade, if you see no value in it don't buy it , it is just another option in the market

post #14230 of 18280

Too many words, just find a balanced amp somewhere n listen to it for yourself...

there aint no other better way to settle this on a personal basis.

To my ears, the SE vs Balanced on the Audiogd NFB10.32 is sonically different enough to put a smile on my face.

:D

 

that said,

i find myself plugging the hd650 into a tube amp more often than not.

watching those tubes glowww, the warmth...its a kind of pleasure hard to beat.

:beerchug:

post #14231 of 18280

I have ordered an amp that is capable of balanced output so i have just finished chopping up a headphone cable to add an XLR connect to it.  So having read the above should i forget about running balanced and put the original TRS socket back onto the cable?      ...yeah right.

 

I would like to hear from owners of fully balanced dac/amp/headphone setups that say its not an improvement.  In the meantime i will be looking forward to experiencing it for myself.

post #14232 of 18280

Has anyone here bought any HD650 cables from ebay? My stock cable is starting to wear out at the ends. I'm just looking for ones that are well built, sturdy, and are made from nice material. Also relatively cheap. I'm seeing some of them are under $50 (some from China, some from the USA), and I was wondering if anybody knows a good and reliable seller.

post #14233 of 18280
Quote:
Originally Posted by Miracles View Post
 

Has anyone here bought any HD650 cables from ebay? My stock cable is starting to wear out at the ends. I'm just looking for ones that are well built, sturdy, and are made from nice material. Also relatively cheap. I'm seeing some of them are under $50 (some from China, some from the USA), and I was wondering if anybody knows a good and reliable seller.

 

Check the bellow link if you like the stock cable.

 

http://www.amazon.com/Replacement-Cable-SENNHEISER-Headphones-HD650/dp/B0028PGXRE/ref=sr_1_1?ie=UTF8&qid=1383534169&sr=8-1&keywords=hd650+cable

post #14234 of 18280

Sennheiser is also great for stocking parts for their products for years afterwards.  I continue to be able to replace everything on my ancient HD580.  Too bad my HD-414 crumbled to dust a long time ago. :)

post #14235 of 18280
Quote:

Thanks for the link. I'm actually in Canada, and it says they cannot ship to my address. I could probably hit up Sennheiser Canada for a replacement stock cable, but I just wanted to see what's out there other than the stock cable. Ideally I'm looking for something that's less than $50. So far ebay seems to have a few of them under $50, but I'm just wondering if anyone here have any experience with any good and reliable sellers out there.

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