[x RELIC x]

I get the more purist approach but plain and simply put, some headphone will need more power. Hopefully this simple oversight doesn't deter my original question.

So, with the HD650's sensitivity rating of 103dB SPL @1kHz, 1Vrms and an impedance of 300 Ohms what makes anyone think the Mojo can't drive the HD650 with it's 3Vrms @ 300 Ohms? Mojo has plenty of power. Synergy is a completely different conversation. I've read so many thoughts that the Hugo does fine yet the Mojo is underpowered. Mojo and Hugo have the same power output. Again, synergy and preference, not drive ability question. The math doesn't support the myth that the Mojo can't (technically) drive the HD650.

 

[howdy]

So, with the HD650's sensitivity rating of 103dB SPL @1kHz, 1Vrms and an impedance of 300 Ohms what makes anyone think the Mojo can't drive the HD650 with it's 3Vrms @ 300 Ohms? Mojo has plenty of power. Synergy is a completely different conversation. I've read so many thoughts that the Hugo does fine yet the Mojo is underpowered. Mojo and Hugo have the same power output. Again, synergy and preference, not drive ability question. The math doesn't support the myth that the Mojo can't (technically) drive the HD650.

Well said Craig!

 

[JWahl]

I get the more purist approach but plain and simply put, some headphone will need more power. Hopefully this simple oversight doesn't deter my original question.

 
If you're driving really low efficiency headphones like the HE-6 or K1000, something like the Schiit Jotunheim or Mjolnir 2 should do well, especially on the balanced output.  Even the HE-560 can soak up some current, as the Valhalla 2 will audibly distort with them.  I'm not sure how the Mojo drives the HE-560 though, probably better than the Valhalla 2 in that regard.  In regards to power, the Mojo should do fine with all but maybe some low efficiency Planars, but it may drive them OK.  Might just drain the battery faster if anything.  Beyond that though, it just depends on the type of sound you're looking for.  I tend to prefer the spacious sound and detail of a well designed, transformer coupled tube amp.  But that's just my preference.

 

[DoctaCosmos]

Never said anything about the mojo not being able to drive the 650. My original question was that I acknowledge the mojos specifications being ridiculous good. Seeing that they are so good, it'd be easy to bottleneck the specifications if I were to add an external amp. I fully understand different tonal characteristics of amps but that's not what I was asking.

 

[DoctaCosmos]

All good don't worry about it

 

[GRUMPYOLDGUY]

Not speculation, sorry this is way off topic.  Die shrinks are well documented for 3 decades plus.  When any architecture is moved to a smaller die there is always energy improvements.  You can move any same chip design to any die shrink and see less power consumption which also has less heat.  Moving to smaller die doesn't increase performance clock for clock if architecture is same it should perform the same.  However many architecture take in heat considerations and don't need to ramp down clock speeds as often so they may appear to perform faster.  But if you where running both at 100% and max clocks were the same they would perform the same with one using more power.  Also when moving a architecture to a smaller die many companies will increase the max clocks because there is more wiggle room in the heat and power department, so you rarely see a die shrink without at least clock speed change.  But most die shrinks come with completely new architecture so you don't think or hear about it often.  But there is plenty of architectures through out the years that have received die shrinks only.

There is the claim on the Artix-7 product intro webpage that 28nm process gives up to 50% power savings over 45nm process. https://www.xilinx.com/products/silicon-devices/fpga/artix-7.html

This is for a specific design change. I'm wondering how one estimates power savings as a function of percentage reduction in transistor size in general terms.

 

[GRUMPYOLDGUY]

I would buy a mojo again, but they don't pair well with the Campfire Andromedas................so I guess I have to find an alternative.

In what sense? I used the CA Andromeda with the Mojo without any issues.

I did opt to use an amp in between so I didn't have to have a ridiculous amount of digital attenuation, but to be honest it fixed a problem that was never an audible issue to begin with.

 

[GRUMPYOLDGUY]

Impossible. 24 bit is basically just used to get more headroom during recording and mixing. 16 bit already has a 96dB signal to noise ratio.

Achievable dynamic range, not SNR. And more than 96dB with dithering. Took me a while to wrap my head around that one ... Still not so sure about it.

 

[GRUMPYOLDGUY]

Never said anything about the mojo not being able to drive the 650. My original question was that I acknowledge the mojos specifications being ridiculous good. Seeing that they are so good, it'd be easy to bottleneck the specifications if I were to add an external amp. I fully understand different tonal characteristics of amps but that's not what I was asking.

The performance of well designed amplifiers is, IMO (based on my own subjective experience), good enough that any artifacts produced are inaudible.

That said, if you were to measure it, obviously any additional analog stage would yield poorer performance than what is measured directly at the DAC output. This is of course true of any device, not just the Mojo.

 

[liyzag1]

how is the mojo different from the LPG sounding wise ???
 
does the LPG sound alot like the ak240 as i own one 
 
if LPG sounds like the ak240 , i have somewhat of an idea what LPG sounds like 
 
so any1 can give the difference between mojo and ak240/ LPG ???
 
thanks a ton !!

 

[GRUMPYOLDGUY]

how is the mojo different from the LPG sounding wise ???

 
does the LPG sound alot like the ak240 as i own one 

if LPG sounds like the ak240 , i have somewhat of an idea what LPG sounds like 

so any1 can give the difference between mojo and ak240/ LPG ???

thanks a ton !!

This is what you want:

http://www.stereophile.com/content/astellkern-ak240-portable-media-player-measurements

http://www.stereophile.com/content/chord-electronics-mojo-da-headphone-amplifier-measurements

 

[x RELIC x]

Never said anything about the mojo not being able to drive the 650. My original question was that I acknowledge the mojos specifications being ridiculous good. Seeing that they are so good, it'd be easy to bottleneck the specifications if I were to add an external amp. I fully understand different tonal characteristics of amps but that's not what I was asking.

True. Apologies for quoting you there. I went off the rails after reading many posts on the matter elsewhere. :redface:

Anyway, IMO, adding an amp will reduce objective performance (and I'm sure many know I'm a fan of measured performance), but a bottleneck is really only a bottleneck if the user doesn't enjoy what it brings to the table. Many users really enjoy the Schiit Jotunheim for example, yet others find it too bright with their headphones. In that case the answer is both a bottleneck and an enhancement. Only the listener can determine what produces the best sound for them.

 

[analogmusic]

Don't know this makes any sense, but since I changed my Iphone 6 battery yesterday, Mojo sounds even better than ever (I use Mojo 100 % from my Iphone)
 
I did notice that many times while playing music, the Iphone would send distorted data to the Mojo, and I would then have to unplug the USB from the Mojo and reconnect it to re-establish the connection.
 
It doesn't make any sense to me at all, but the the battery was really completely depleted on the Iphone (and losing charge too quickly), no idea why this would impact on sound quality.

 

[liyzag1]

This is what you want:

http://www.stereophile.com/content/astellkern-ak240-portable-media-player-measurements

http://www.stereophile.com/content/chord-electronics-mojo-da-headphone-amplifier-measurements

thanks a ton !!

 

[music4mhell]

https://youtu.be/hCYUujl1zTM

Chord's comparison of fpga to dac chip..

enjoy..thank you chord for such knowledgeable video..