Do my Sundaras need more power or are they just faulty?

[solderdude]

You calculate the needed voltage.
Then the tricky part starts if headphones have a varying resistance.
For Sundara it is easy as it is resistive.
For the M50X it is also as good as resistive so currents are easily calculated.
For headphones with wildly varying impedances calculating the current is tricky as that will vary er frequency.

There is another catch though. When the amp section is current limited then, at the moment there is not enough current the voltage also will not reach the desired value.
This is what this makes a bit more complicated because the maximum voltage is not only determined by the voltage limit but also by the impedance.

But for Sundara this is not frequency dependent.

 

[Cahudson42]

Long thread so apologize if covered, but it's often asked of Qudelix if the 5k can adequately drive Sundara/Planars. So they have provided a series of tables with voltage, current, and max SPL. Here is Sundara:
https://docs.google.com/spreadsheet...VQcwafhkuNeq8Lx7FOAzqEqoPqE/edit?usp=drivesdk

And to put SPL in perspective, this:
https://www.qudelix.com/blogs/5k-dac-amp/power-budget

 

[Nango]

You can determine the current by applying Ohm's Law. If we know that the output voltage is 2.82V and the load is 37 Ohms, then we can plug those values into the equation.

I = V / R

And therefore:

2.82 / 37 = 0.076A or 76mA

All these headphone Maths regarding efficiency (quoted as spl/mW) and sensitivity (quoted as spl/V) and what is good for what here: http://archimago.blogspot.com/2021/03/measurementsmusings-headphone-impedance.html?m=1

 

[BartekG]

That would effectively be clipping, which is volume dependent.

Again, are all of these sighted comparisons? Does it occur at lower volume levels?

My comparison is sighted, I don't hear the difference in bass at a lower volume.
Another thing that comes to my mind is that the amp may not be getting high enough voltage to reach advertised power, but that shouldn't be the case with integrated dac/amp.

 

[devopsprodude]

You need to burn them in before making any assesments. The manual says 150 hours.

Totally unnecessary for the problem described in the OP. My Sundara cans had great soundstage performance fresh out of the box.

 

[Cahudson42]

Long thread..admit I've lost track..

Perhaps OP might update everyone?
Mono test:
You have tested for L and R channel separation, and cable shows no short between L and R +'s?
Tried a different cable? (If possible...)
Khandas - with an efficient IEM or similar, also has channel separation? Not mono?

Power test:
Sundara has been tried on alternate amp? Even if just your Stereo, AVR, or TV? All sound as 'bad' as Khandas?

Crosstalk in Khandas:
IEM has been tried with Khandas and Phone. 'Soundstage' similar?

At this point, I personally would probably be looking to get a $100 HP amp. (or maybe a Qudelix and Balanced cable) Alternately, I might get an $170 HE400i 2020, which if I can remember, has 92db sensitivity vs. Sundara 93, and is a similar HiFiman planar single-sided magnet design.. Return worst. Or both.. And/or Khandas..

Good luck ..and hopefully keep having fun

 

[nohomo_sapiens]

Long thread..admit I've lost track..

Perhaps OP might update everyone?
Mono test:
You have tested for L and R channel separation, and cable shows no short between L and R +'s?
Tried a different cable? (If possible...)
Khandas - with an efficient IEM or similar, also has channel separation? Not mono?

Power test:
Sundara has been tried on alternate amp? Even if just your Stereo, AVR, or TV? All sound as 'bad' as Khandas?

Crosstalk in Khandas:
IEM has been tried with Khandas and Phone. 'Soundstage' similar?

At this point, I personally would probably be looking to get a $100 HP amp. (or maybe a Qudelix and Balanced cable) Alternately, I might get an $170 HE400i 2020, which if I can remember, has 92db sensitivity vs. Sundara 93, and is a similar HiFiman planar single-sided magnet design.. Return worst. Or both.. And/or Khandas..

Good luck ..and hopefully keep having fun

I posted an update a few days ago about ordering a new amp and new cables to see if there's any improvement. My new amp Topping A50S and balanced cable should come tomorrow hopefully. I will post an update when they arrive.

I compared the Sundara running off my Apple USB C dongle with my Khadas and they sound pretty similar overall with similar soundstage if that answers your question.

 

[MrPeabody]

When someone asks for a recommendation that includes listening with Hifiman Planar headphones, ... I answered him directly and clearly with yes your amp is too weak...

But, even with all that you wrote, you did not manage to give any truly good reason for why you thought the amp he was using is too weak. I know that you think that you did, but you didn't. What you mostly did was to say that speakers and headphones will not sound their best unless the amplifier is capable of delivering power greatly in excess of the amount the speakers or headphones are actually using. You said this repeatedly, and in a way that was obtuse but still clear enough that there is no room for doubt or denial that this is what you were arguing. I am perpetually annoyed by this particular notion (which you share with plenty of other people) because anyone with a basic reasoning ability should have no difficulty realizing that it does not make sense, i.e., that it does not make sense that the sound from a speaker or headphone would be affected by the ability for the amplifier to deliver power greatly in excess of the amount of power that the headphones or speakers are actually using at the given volume level. No special training of any sort should be needed for anyone to figure out that this notion just doesn't make sense. Once a week at least, we have a new thread on ASR where someone expounds this same spurious notion. It is obviously one of the most popular notions held dear by very many audiophiles, but it does not make any sense at all.

There is no law that says we must purchase the top measuring equipment, or not buy the lower measuring equipment. We buy what think we might like, and keep what we do like. I've listened to a lot of hardware, so I know what I like.... We are not a slave to measurements. If I listen to equipment that provides me joy when listening, the measurements inform me, but the measurements don't rule my decision-making. For my own purchases, the final deciding factor is how the device gives me joy when listening to music.

That's all fine and good, but I don't think it really has anything to do with what the OP was asking about.

Several times you mentioned or alluded to instantaneous power delivery, i.e., the need for the amplifier to deliver power in an instantaneous manner. Okay, but the primary reason for this need is that power delivered into a given load is proportional to the square of the voltage across the load. Hopefully it is apparent that the output voltage must track the input in a linear manner, i.e., that the output voltage is required to be a linear replica of the input voltage, and that this is the primary reason that it is necessary for power delivery to increase and decrease in an instantaneous manner. As such, it should be apparent that when looking at an amplifier's required behavior from an instantaneous perspective, the only reason that most any amplifier wouldn't do what it is required to do, with respect to instantaneous delivery of power, is if the output voltage is not tracking the input signal in an instantaneous manner, to the extent that this is necessary in accordance with the upper frequency limit of human hearing. People who truly understand the required behavior of an amplifier understand this with perfect clarity, and as such they focus on distortion, because if the output voltage does not track the input voltage in the instantaneous manner that is required, this will manifest as distortion. People who have this kind of intimate, proper understanding of amplifiers do not make repeated use of words like "slam", and when they are concerned with the amplifier's ability to respond to the signal in an instantaneous manner, they ordinarily make it about voltage and distortion, not about power.

 

[Rayman30]

But, even with all that you wrote, you did not manage to give any truly good reason for why you thought the amp he was using is too weak. I know that you think that you did, but you didn't. What you mostly did was to say that speakers and headphones will not sound their best unless the amplifier is capable of delivering power greatly in excess of the amount the speakers or headphones are actually using. You said this repeatedly, and in a way that was obtuse but still clear enough that there is no room for doubt or denial that this is what you were arguing. I am perpetually annoyed by this particular notion (which you share with plenty of other people) because anyone with a basic reasoning ability should have no difficulty realizing that it does not make sense, i.e., that it does not make sense that the sound from a speaker or headphone would be affected by the ability for the amplifier to deliver power greatly in excess of the amount of power that the headphones or speakers are actually using at the given volume level. No special training of any sort should be needed for anyone to figure out that this notion just doesn't make sense. Once a week at least, we have a new thread on ASR where someone expounds this same spurious notion. It is obviously one of the most popular notions held dear by very many audiophiles, but it does not make any sense at all.



That's all fine and good, but I don't think it really has anything to do with what the OP was asking about.

Several times you mentioned or alluded to instantaneous power delivery, i.e., the need for the amplifier to deliver power in an instantaneous manner. Okay, but the primary reason for this need is that power delivered into a given load is proportional to the square of the voltage across the load. Hopefully it is apparent that the output voltage must track the input in a linear manner, i.e., that the output voltage is required to be a linear replica of the input voltage, and that this is the primary reason that it is necessary for power delivery to increase and decrease in an instantaneous manner. As such, it should be apparent that when looking at an amplifier's required behavior from an instantaneous perspective, the only reason that most any amplifier wouldn't do what it is required to do, with respect to instantaneous delivery of power, is if the output voltage is not tracking the input signal in an instantaneous manner, to the extent that this is necessary in accordance with the upper frequency limit of human hearing. People who truly understand the required behavior of an amplifier understand this with perfect clarity, and as such they focus on distortion, because if the output voltage does not track the input voltage in the instantaneous manner that is required, this will manifest as distortion. People who have this kind of intimate, proper understanding of amplifiers do not make repeated use of words like "slam", and when they are concerned with the amplifier's ability to respond to the signal in an instantaneous manner, they ordinarily make it about voltage and distortion, not about power.

Even if you are correct, and you very well may be.... this reads as incredibly condescending. We are all enthusiasts and students to this hobby, try and be cordial and understand not everyone has an engineering degree, keep it simple for us common folk eh!

 

[MrPeabody]

Even if you are correct, and you very well may be.... this reads as incredibly condescending. We are all enthusiasts and students to this hobby, try and be cordial and understand not everyone has an engineering degree, keep it simple for us common folk eh!

When you say that this reads as "incredibly condescending", you say it as though it were some sort of objective fact, not merely your personal opinion. I do not think it was condescending in any untoward manner at all. It was a well-worded, matter-of-fact statement of what was wrong with what he had repeatedly written, and had written in a manner that was every bit as defiant as it was incorrect. I happen to be fond of well-worded, matter-of-fact statements of this sort, and if statements of this sort come across to some other people as condescending, so be it. I will note that what brought this out of me was that (1) what he wrote was exceedingly far removed from reality, and (2) he repeated it so many times that I literally could not keep track, and each time that he did, he used the same language and expounded the same patently incorrect beliefs.

He repeatedly defended his recommendation that a more powerful amplifier was the cure for an illness that was so poorly defined that it was a fool's errand for anyone to make any suggestions at all. To defend his haphazard recommendation, he made repeated use of words like "slam", and he repeatedly argued that when two different amplifiers deliver identical power to a particular speaker or headphone that the two different amplifiers will nevertheless deliver the power in some nebulously different way that will lead to the speakers or headphones sounding different. At face value this does not make sense unless the difference is attributed expressly to a difference in distortion. He never once mentioned distortion.

 

[LaL]

10 Volts upwards they need, better 12 V. I just hope @amirm wont test it only with the ADI-Dac.

The Sundara really do sound much better with more power, and they are hard to drive properly.
At first I felt they were a bit lifeless and at 32-ohm's I was just trying them on low gain.
But now I only use the full +18 gain on the Zen-Can amp and a little EQ and they sound excellent.
Max Output (11.0V / 1890mW @64 Ohm)

 

[bogart]

The Sundara really do sound much better with more power, and they are hard to drive properly.
At first I felt they were a bit lifeless and at 32-ohm's I was just trying them on low gain.
But now I only use the full +18 gain on the Zen-Can amp and a little EQ and they sound excellent.
Max Output (11.0V / 1890mW @64 Ohm)

I see you have had several EQ settings for these

 

[LaL]

I see you have had several EQ settings for these

Yes, through trial and error I arrived at the only one worth using.
Now the only time I change anything is to add just a bit more sub-bass on some tracks.

 

[Seeping81]

I'm not talking about subtle differences, I am talking about A sounds great / B sounds like crap, simple and easy to confirm - big differences.

Don't doubt your ears, doubt your experience in judging what is causing the difference in what you are hearing.

If you are enjoying the sound of A, but B is not doing it for you - you are hearing clear differences, not subtle differences, then don't doubt your ears.

The Sundara headphones sound like crap to the OP when driven with an amp measured as capable of a maximum of 10mW, as his own posted personal experience demonstrates.

While the Sundara headphones are widely reported to sound great with an amp capable of 1W or greater - as many happy Sundara owners report.

What is your conclusion?

My conclusion is that math doesn't always tell you what is going to sound best. Mathematically the numbers balance, but in reality, you always want an amp with far more headroom than is needed at a minimum to drive a load.

Clearly, an amp that is maxed out delivering 10mW doesn't have enough power delivery to provide satisfying sound to the Sundara, even if the Math says 10mW is "enough" power.

An amp can also have more than enough power listed in its specification and yet not be able to drive the load satisfactorily, as I described earlier where a lower spec'd 100W Class A Stereo amp clearly delivered superior sound to a pair of 500w Monoblocks.

Math doesn't cut it when other considerations aren't considered

Hi everyone,

I am new here, but I’d like to chime in on this question of how much power it takes to a pair of Sundaras.

I have both the Sundaras and Amandas and I’ve found that they both require more power than their sensitivity ratings would indicate to sound good. I have an Archel 2 GMR amplifier and while it’s not the most powerful amp (1W @ 16ohms), calculations would indicate it is capable of providing more than enough power to both headphones. I know the volume knob is far from maxing out (sorry, I can’t remember what o’clock). Also in Amir’s review of the Archel amps, he does mention its low current measured for low impedance loads. Anyway, initially when I received both headphones I thought they sounded pretty bad, especially for their price. The sound was thin and distorted, especially on vocal oriented tracks (especially female vocals). First I wondered if this is what planars sound like... Eventually though I discovered that both headphones, especially the Ananda, sounded so much better and as I expected they should sound on my Audio GD R2R11 dac/amp (3.5W @ 16 ohms I believe), which is a full class A amp with a much bigger power supply. It’s well known that tube amps are not suitable for planars, but I think my Archel is similar. If I plug a pair of dynamic headphones into the Archel, then all is great, so I don’t believe the power rating of the amp tells the whole story. For planars, the amount of current an amp can produce at a low impedance is even more important. I, however, am not sure how to figure out how much current an amp can put out beyond a straightforward power calculation that usually doesn’t tell the whole story.

So I agree with @hmscott that despite the A90’s high power rating, it probably produces less current than the Xduoo TA20, though I’m not all that familiar with it (or what it is).

Just my two cents. Thanks for reading!

 

[Veri]

So I agree with @hmscott that despite the A90’s high power rating, it probably produces less current than the Xduoo TA20, though I’m not all that familiar with it (or what it is).

Just my two cents. Thanks for reading!

Well, no, it produces plenty of current too. A90 is powerful all-around, especially with balanced inputs and from a balanced output.

 

[Seeping81]

Well, no, it produces plenty of current too. A90 is powerful all-around, especially with balanced inputs and from a balanced output.

Yeah, the A90 vs Xduoo TA-20 comparison probably isn’t a good example of not having enough current for planars. The amp mentioned in the OP is a better example and maybe my Archel 2 GMR.

On another note though, I’m trying to understand why the Drop THX One Linear Amp comes with a 0.25A power supply when the Cavalli Tube Hybrid has a 1.25A supply. Is it just cuz of the tubes? The THX amp has more power too, but will the Cavalli amp actually work better with planars?

 

[Veri]

On another note though, I’m trying to understand why the Drop THX One Linear Amp comes with a 0.25A power supply when the Cavalli Tube Hybrid has a 1.25A supply. Is it just cuz of the tubes? The THX amp has more power too, but will the Cavalli amp actually work better with planars?

Well the drop One comes with a whopping 30V PSU. But yes the tube thing might need the overall higher power rating.

 

[hmscott]

Hi everyone,

I am new here, but I’d like to chime in on this question of how much power it takes to a pair of Sundaras.

I have both the Sundaras and Amandas and I’ve found that they both require more power than their sensitivity ratings would indicate to sound good. I have an Archel 2 GMR amplifier and while it’s not the most powerful amp (1W @ 16ohms), calculations would indicate it is capable of providing more than enough power to both headphones. I know the volume knob is far from maxing out (sorry, I can’t remember what o’clock). Also in Amir’s review of the Archel amps, he does mention its low current measured for low impedance loads. Anyway, initially when I received both headphones I thought they sounded pretty bad, especially for their price. The sound was thin and distorted, especially on vocal oriented tracks (especially female vocals). First I wondered if this is what planars sound like... Eventually though I discovered that both headphones, especially the Ananda, sounded so much better and as I expected they should sound on my Audio GD R2R11 dac/amp (3.5W @ 16 ohms I believe), which is a full class A amp with a much bigger power supply. It’s well known that tube amps are not suitable for planars, but I think my Archel is similar. If I plug a pair of dynamic headphones into the Archel, then all is great, so I don’t believe the power rating of the amp tells the whole story. For planars, the amount of current an amp can produce at a low impedance is even more important. I, however, am not sure how to figure out how much current an amp can put out beyond a straightforward power calculation that usually doesn’t tell the whole story.

So I agree with @hmscott that despite the A90’s high power rating, it probably produces less current than the Xduoo TA20, though I’m not all that familiar with it (or what it is).

Just my two cents. Thanks for reading!

Yup, and from all the reports of long time Ananda (Sundara?) owners once they got a high power amp 15W(!) or used a speaker amp matched to an XLR headphone jack, they were in heaven. No, it didn't do them in, they finally heard the headphones really sing

I've got other fish to fry (fish tacos, actually), and it will be a while before I make another AMP move, as 2W+ is making me happy for now

Scott

 

[hmscott]

Well, no, it produces plenty of current too. A90 is powerful all-around, especially with balanced inputs and from a balanced output.

Yet it doesn't sound anywhere near as forceful or dynamic as the Xduoo TA-20... weird, right? I still try to switch back to the A90 every so often, I even went a whole day once, but when it was "movie time", I swapped back to the Xduoo TA-20, ahhh.

 

[Rayman30]

When switching the Sundara from SE output to 4.4mm balanced on my A50S, I had the perception that there was an increase in bass (Punch and Slam) and so did my friend. I notice less of a difference with my Ananda, but that is not surprising considering their lower impedance.