[mulder01]

I don't think most people realise how little power their headphones consume at normal listening volumes.  But also I don't think people are willing to try less expensive amps with their super expensive headphones in the fear that they are missing out on something.
 
However, on the other side of the argument, there is an article that was written over 50 years ago that explores the question of "How much power is enough" here:
http://www.stereophile.com/content/amplifier-power-how-much-enough#zb5GKiUdI85VgEXg.97
Which is as inconclusive today as it was then.  Though it seems to point toward needing headroom.  There are other arguments about how different manufacturers do their measurements - often figures are quoted at a certain point - at 1mW and 1kHz for example, but the distortion characteristics may not be linear across the entire frequency or power range.  
 
I have recently been using a DAP to power my Abyss.  I only found out after I bought it that it will only put around 120mw into them.  If I knew that at the time I may not have bought it out of fear of not having enough power.  However, now that I've had time to live with it, I have found that the VU meter peaks out at about -6db at my normal responsible listening volume.  Which is one quarter of the amp's max output.  I haven't measured the volume, but a 46ohm load with 85 dB/mW sensitivity requires 32mW (0.032w) for 100dB SPL (moderate volume), so that sounds about right.  Yet there are some insisting you need a 100w speaker amp to drive the Abyss to it's potential.  Why?  Probably comes down to design and voicing and the pairing complementing eachother and being subjectively satisfying to the listener.
 
Why does the Mojo get a bad wrap with the LCD-4?  Either the figures quoted on the mojo are misleading, people who think that it's fine are too afraid to say anything out of fear of being ridiculed on the forum by people with more expensive gear or they've been reading the forum too much and have set themselves up to not like it without doing a proper A/B test or giving it a proper chance.  Who knows.  I'd say if people are happy to use their Mojo then great.  *edit* I was going to use the expression "more power to you" but I don't think it was the best choice.  Gonna go with "great".

 

[Boerd]

​There is vested interest in articles like that. Some sell more power (and charge more money) and some find "reasons" for it. Measure your amp across the entire Voltage/Power range, make sure it doesn't distort at low levels, stays low until it runs out of juice, it has low impedance, etc. Known quantities. No religion. Plug in the output impedance of the head amp, the headphone impedance, determine output loss, etc. etc.
Once your headphone is driven to 110db on a clean signal you are done! When you listen at 80 db you have a lot of headroom. You can even listen at 100db or 105 db (and still have 5db headroom!) but it better be rare or else...

 

[Smazz]

 
​Do you even know what the loudness in db is for Dave driving the LCD-4 before it starts clipping? Answer: 113db and change (6.8Vrms into 200 ohms through a 0.005 ohms output impedance). Of course you can show some measurements with Dave distorting at normal levels (like 100 db) right? You do understand the LCD-4 needs 0.5 Vrms to play at 90 db, do you? http://www.innerfidelity.com/images/AudezeLCD4.pdf
Let me guess - you also need to use k$ cables soaked in snake oil so that the electrons slide faster and distort less - no measurements needed.
Don't let simple physics and measurements get in the way - give us some solid reasoning for your statements.

Not sure what prompted this condescending tone, I'm merely sharing what I experience while listening. If these are the type of replies you are gonna bring to this thread, it takes the fun out of keeping up with the chat. From my experience, the LCD-4 starts clipping for me when the Chord Dave reaches 9 dB. 

 

[Boerd]

My bad for the tone but it isn't fun to read things that make no sense either. Are you saying you have a defect Chord Dave? Otherwise saying it is clipping and cannot drive the LCD-4 makes no sense. The definition of clipping btw is 1% THD + N.
Mojo, a much cheaper amp (600$) can drive the LCD-4 to 110 db before clipping. That is very loud. And Dave is in another league than Mojo.

 

[x RELIC x]

From my experience, the LCD-4 starts clipping for me when the Chord Dave reaches 9 dB. 

If listening at +9dB on the DAVE with the LCD-4 then either your source music is mastered at a very low level or you are listening extremely loud, there's nothing else to it.

Jumping in to the conversation about power vs preference. for example, a lot of people reported that the ALO CDM would drive the HE-1000 to it's "full potential" and that there's no way the Mojo could. Guess what, in balanced mode the CDM only outputs 125mW in to 32 Ohms. The Mojo outputs 600mW (quoted by Rob Watts) in to 32 Ohms.

I guess that many 'powerful' amps simply have a certain tonality that people love so they automatically equate that more 'power'=better. The thing is, if there's enough power from the amp for the peak dynamics of the track to reach a certain dB level then the unused power from the amp isn't seen by the headphone and is simply a waste.

 

[Smazz]

  My bad for the tone but it isn't fun to read things that make no sense either. Are you saying you have a defect Chord Dave? Otherwise saying it is clipping and cannot drive the LCD-4 makes no sense.

What I'm saying, is I enjoy listening at higher than average listening volumes. Most amps I have encountered, including the Chord Dave, cannot push the LCD-4 to those volumes without clipping or distorting. People enjoy music at different volumes, I've talked to many that own the Chord Dave and enjoy the amp, it powers the LCD-4 no problem at the volumes they enjoy listening at. However, I have met others that agree with me, including close friends that I attend meets with, who feel the Chord Dave's amp leaves a little to be desired when powering the 4s. I can't argue numbers with you, I got a C in physics about 14 years ago, but from my personal experience, the Chord Dave's amp and my recent purchase of the Eddie Current 445 do not push my LCD-4s to the volumes that I enjoy listening. These assertions come from my personal experience, they are not facts by which everyone must abide. 

 

[manpowre]

 
Not sure what prompted this condescending tone, I'm merely sharing what I experience while listening. If these are the type of replies you are gonna bring to this thread, it takes the fun out of keeping up with the chat. From my experience, the LCD-4 starts clipping for me when the Chord Dave reaches 9 dB. 

 
I would like to jump in with a little different perspective. I never listened to Chord Dave, so I cant really add info there, but I have noticed it has less power to feed headphones than eg. my Violetric V281. But I have a question, but first a quick elaboration;
 
When I set my V281 to 0 db pre-amp, I have to turn the volume knob to 2-3 oClock to get normal listening levels, and at that high volume knob I can definetely hear edges rounded off in the music, like more soft tonality than the cirsper sound at lower volume levels. Then I set V281 to +6 db pre-amp and I can have normal listening levels at 11 oClock and even have the room to go to 12 oClock without the rounding off edges starts. I never had any clipping or anything like that on the V281.
 
Now to my question, 
 
If people that own LCD4 and the Chord Dave can hear clipping at higher volume levels, I assume the "volume knob" is turned high to get normal listening levels, do you experience softer / rounded off edges in the music ?

 

[x RELIC x]

I would like to jump in with a little different perspective. I never listened to Chord Dave, so I cant really add info there, but I have noticed it has less power to feed headphones than eg. my Violetric V281. But I have a question, but first a quick elaboration;

When I set my V281 to 0 db pre-amp, I have to turn the volume knob to 2-3 oClock to get normal listening levels, and at that high volume knob I can definetely hear edges rounded off in the music, like more soft tonality than the cirsper sound at lower volume levels. Then I set V281 to +6 db pre-amp and I can have normal listening levels at 11 oClock and even have the room to go to 12 oClock without the rounding off edges starts. I never had any clipping or anything like that on the V281.

Now to my question, 

If people that own LCD4 and the Chord Dave can hear clipping at higher volume levels, I assume the "volume knob" is turned high to get normal listening levels, do you experience softer / rounded off edges in the music ?

I don't own the LCD-4, and I never go that loud with my headphones as they are relatively easy to drive but I'll share the basic design difference with the DAVE that sets it apart from almost all DAC/amp combo's.

The DAVE only has the one output stage (the critical I/V conversion) and no buffer, filter or gain amplification stage. In essence the DAVE drives headphones from the line-out of the DAC in the name of transparency. Because every component that's added to the chain reduces transparency Rob designs all his DACs without a separate headphone amp and is able to do this because of the clean WTA filter in the FPGA to his discrete Pulse Array DAC that does not require the other typical amplification stages in the end. His designs pretty much measure on point to the threshold of clipping.

I'd be interested as well to read from DAVE/LCD-4 owners if they hear any 'rounding' or unfavorable effects as the volume gets louder. On the other hand, if the LCD-4 needs 4.5Vrms to get to 110db (66% of the DAVE's total power output) then surely if running at +9dB (89% total volume) one might expect to hear anomalies at these levels.

Obviously for some the DAVE can't drive the LCD-4 to loud enough volume without clipping (+9dB is really quite a lot) but in general it's a very clean and transparent unit letting the headphone colour the sound, not an amp.

 

[Modwright01]

Very interesting reading, now you can see how it can be a probem when  a headphone is hard to drive.
 
 
As far as i'm concerned, with the chain computer > Mojo > EAR HP4 > LCD 4 100ohm with the mojo on line out mode,
 
the volume know on the HP4 is at 12 o'clock 99% of the time to obtain a level range between 75 and 85 db maximum.
 
To obtain the same volume with the mojo i have t go to after the violet or even further, the sound start to be fatiguing fastly and I have to play all the time with the volume to be confortable when I can listen my desktop amp for hours let the volume knob as t is....
 
When I say it is a problem when Audeze make the new LCD 4 harder to drive, it is. And the classique answer : "you have just to buy a more powerfull amp", well right, but it seems to be harder that it should be to find an amp to driver properly the new LCD 4, when it is really easy with the 100ohm...   

 

[Hifi59]

Do explain your reasoning :rolleyes:

I'm guessing that he's trying to say that an underpowered amp being overdriven while trying to drive the LCD-4 is not going to do them justice versus amp with power to spare.

 

[manpowre]

  Very interesting reading, now you can see how it can be a probem when  a headphone is hard to drive.
 
 
As far as i'm concerned, with the chain computer > Mojo > EAR HP4 > LCD 4 100ohm with the mojo on line out mode,
 
the volume know on the HP4 is at 12 o'clock 99% of the time to obtain a level range between 75 and 85 db maximum.
 
To obtain the same volume with the mojo i have t go to after the violet or even further, the sound start to be fatiguing fastly and I have to play all the time with the volume to be confortable when I can listen my desktop amp for hours let the volume knob as t is....
 
When I say it is a problem when Audeze make the new LCD 4 harder to drive, it is. And the classique answer : "you have just to buy a more powerfull amp", well right, but it seems to be harder that it should be to find an amp to driver properly the new LCD 4, when it is really easy with the 100ohm...   

 
I wouldnt say its a problem for the LCD4 to be 200 ohm, Sennheiser HD650 is 300 ohm, so alot of people have amp's already ready when they go for LCD4. Even Focal Utopia deserves a proper amp to get the punch, but the impedance is lower so it can also be used on lighter equipment. Its the manufacturers choice to choose the resistance based on their experience with returns and possible failures, so I think we can leave that specific discussion, but the question with high end dac's like Chord Dave where there is a headphone output has this rounding off the edges as I experience and other people also experience on solid state amp's when the volume knob is too high. I guess the way the amplification of the Dave is made in a way that when the amplification cant drive it anymore it starts clipping instead of rounding off the edges. I wonder if the volume in Chord Dave is a digital volume and the amp part is fixed ?

 

[ufospls2]

I can only speak from my personal experience with the Mojo and LCD-4, and that is that it clips at higher volumes, especially if you have EQ'd up the bass a bit. In my opinion, the LCD-4 sounds better with more power behind it, but thats just me. Your mileage may vary and all that. 

 

[JohnnyCakes]

  When I say it is a problem when Audeze make the new LCD 4 harder to drive, it is. And the classique answer : "you have just to buy a more powerfull amp", well right, but it seems to be harder that it should be to find an amp to driver properly the new LCD 4, when it is really easy with the 100ohm...   

 
Life can be unfair sometimes.  but i know that if you put your mind to it, that you will find just such an amp.  you must believe in yourself first, though.  don't ever let anyone tell you you can't reach your dreams.
 
 
btw - dude, if you want to roll the dice with your faulty 100ohm headphones, be our guest.  why are you making such a big deal over something nobody else has a problem with?  literally everyone else here would rather have the 200ohm version that will last over time than the 100ohm version that will likely fail at some point.  and honestly - if you can't afford a proper amp (such as a Moon Neo 430, Headamp mk2, Cavalli, Woo WA-5, or many, many others) to drive the new LCD-4, then you probably can't afford the LCD-4 to begin with.

 

[Boerd]

  Very interesting reading, now you can see how it can be a probem when  a headphone is hard to drive.
 
 
As far as i'm concerned, with the chain computer > Mojo > EAR HP4 > LCD 4 100ohm with the mojo on line out mode,
 
the volume know on the HP4 is at 12 o'clock 99% of the time to obtain a level range between 75 and 85 db maximum.
 
To obtain the same volume with the mojo i have t go to after the violet or even further, the sound start to be fatiguing fastly and I have to play all the time with the volume to be confortable when I can listen my desktop amp for hours let the volume knob as t is....
 
When I say it is a problem when Audeze make the new LCD 4 harder to drive, it is. And the classique answer : "you have just to buy a more powerfull amp", well right, but it seems to be harder that it should be to find an amp to driver properly the new LCD 4, when it is really easy with the 100ohm...   

​IF you refer to 75db or 85db SPL to be obtained from Mojo with an LCD-4 you will find out that 85db is at approx. 0.25Vrms while Mojo puts out 4.5Vrms before clipping (1% THD + noise) and around 4Vrms at 0.00017% THD + noise. You can drive them at 100db SPL with room to spare (10db SPL is generous headroom in terms of SPL headroom).

 

[jlbrach]

  My bad for the tone but it isn't fun to read things that make no sense either. Are you saying you have a defect Chord Dave? Otherwise saying it is clipping and cannot drive the LCD-4 makes no sense. The definition of clipping btw is 1% THD + N.
Mojo, a much cheaper amp (600$) can drive the LCD-4 to 110 db before clipping. That is very loud. And Dave is in another league than Mojo.

I listen to my LCD-4 straight out of the Dave anywhere from -18 to -3 for the most part......would never get to plus 9 and chord has said the dave can go to around +5 before clipping