[Andykong]

   
Okay, re-did the measurement on a lower load (previously 47ohm, now half at 23.5ohm), noticed a huge drop in voltage in the same setting to suggest obvious clipping / limiting. So I lower the volume from max and confirm the voltage drop is gone which leads to two immediate observations: 1) recalculated the output impedance to around 0.4ohm under a smaller volume, which is more inline with what iBasso has claimed. The previous number is higher due to bigger voltage drop between load and no-load under max volume condition, where in both cases iBasso DX50 fails to reach the claimed 3.1V(rms?). It managed only 2.55Vrms @ 47ohm and 1.66Vrms @ 23.5ohm. Current output for DX50 dropped slightly to around 73mA (at max volume). Same 23.5ohm test to X5: voltage is holding at 2.98Vrms (from previous 3Vrms) and current output drops a bit to 288mA (from 300mA). So to the same 23.5ohm load, X5 is driving 7 times more power than DX50 (from the previous 4x @ 47ohm). There is so much power in X5's output that the dummy load actually got warmer during testing, which means X5 is capable of blowing out your headphone in the maxed-out setting, not that I'll suggest you should ever try.
 
Anyway, despite the claimed number I think it is obvious DX50 doesn't quite deliver those number under actual test. X5 on the other hand does (and quite nicely so). Your calculated number is right but those would only be true in theoretical or very ideal condition, such as a very high impedance load which will be much easy for DX50 to drive. With real world 16ohm / 32ohm headphone, it can never achieve those calculated spec. Just go to show that you can't always trust what manufacturer have said (or not said, in this case). 

 


Fiio has published the max. current output of their DAP, X5 is rated at >150 mA, X3 at > 250 mA, so X3 has significantly better driving power when compare to X5?
 
Coming from a traditional HiFi setup background, I certainly appreciate the amount of current that an amplifier can put out determine its driving power, I guess the same will hold the same in HeadFi DAP design.  The obvious index in traditional HiFi game is whether an amplifier can double its output when the impedance drop by half (8ohm vs 4 ohm vs 2 ohm), I wonder is there an easy way out to speculate the current capacity of a DAP or headphone amplifier based on published specifications.
 
So DX50 high gain is hardly 3.1V as published?  You didn't specify the gain setting of X5 and DX50 in your measurements, I assume both units are set in high gain from the figures. In fact, even Fiio website didn't specify the gain setting regarding their DAP output, I have asked here before with no luck, wonder if this is too much trouble for you to measure the X5 output in both LO and Hi gain setting, much appreciated in advance.
 
By the way, I have the ER4s with me, and I can tell you quite definitely that I prefer X5 over DX50 with ER4s at 100 ohm.

 

[cooperpwc]

Good stuff AndyKong and ClieOS.  

 
These are the published specs for the X5:
 
460 mW @ 16Ω, 255 mW @ 32Ω, 28 mW @ 300Ω.
 
Let's do some published specs comparisons on a per channel basis with 16 ohm IEMs:
 
X5:               230 Mw
AK100:          70 Mw
Sony ZX1:     15 Mw
Calyx M:          98.2 Mw  (current specs)
 
Others feel free to add more. It's Chinese New Year here and I am lazy. The point is that X5 is seriously powerful driving IEMs.

 

[cooperpwc]

----

 

[JamesFiiO]

   


Fiio has published the max. current output of their DAP, X5 is rated at >150 mA, X3 at > 250 mA, so X3 has significantly better driving power when compare to X5?
 
Coming from a traditional HiFi setup background, I certainly appreciate the amount of current that an amplifier can put out determine its driving power, I guess the same will hold the same in HeadFi DAP design.  The obvious index in traditional HiFi game is whether an amplifier can double its output when the impedance drop by half (8ohm vs 4 ohm vs 2 ohm), I wonder is there an easy way out to speculate the current capacity of a DAP or headphone amplifier based on published specifications.
 
So DX50 high gain is hardly 3.1V as published?  You didn't specify the gain setting of X5 and DX50 in your measurements, I assume both units are set in high gain from the figures. In fact, even Fiio website didn't specify the gain setting regarding their DAP output, I have asked here before with no luck, wonder if this is too much trouble for you to measure the X5 output in both LO and Hi gain setting, much appreciated in advance.
 
By the way, I have the ER4s with me, and I can tell you quite definitely that I prefer X5 over DX50 with ER4s at 100 ohm.

 
 
Yes, I can confirmed that the specification is tested at high gain. and about the current output, it should be enough if the max output current can keep the same voltage output via low impedance driver. 

 

[JamesFiiO]

  Good stuff AndyKong and ClieOS.  

 
These are the published specs for the X5:
 
460 mW @ 16Ω, 255 mW @ 32Ω, 28 mW @ 300Ω.
 
Let's do some published specs comparisons on a per channel basis with 16 ohm IEMs:
 
X5:               230 Mw
AK100:          70 Mw
Sony ZX1:     15 Mw
Calyx M:          98.2 Mw  (current specs)
 
Others feel free to add more. It's Chinese New Year here and I am lazy. The point is that X5 is seriously powerful driving IEMs.

 
It is quite easy to test the output voltage, output current and output power by a sound card , and the result is reasonable accurate ( not like the THD, S/N you need some very expensive instrument like AP ).  
 
the only thing that I can said is that we try to list more specification with the test condition but not just  output voltage  without test condition  or output power without loader . 

 

[Mython]

James, can I just say that it's nice to see you contributing regularly to these threads, again, and I hope your recovery is progressing well.
 
I also hope you will have a big smile on your face when the X5 is released internationally, because we all know it is going to be a massive success for you, and you and your team deserve it!

 

[Reylaw]

   
 
 
 
 
http://www.head-fi.org/t/661411/fiio-x5-thread-info-updated-on-jan-17th-2014/3855#post_10215001:
 
 
 
 
Also see twister6's remarks about X5 vs E18:
 

I was keen on buying an E17 when i learned that E18 is on its way. I thought it would be perfect for listening with my phone and watching movies with my tablet, when  suddenly after the release of E18 I learned that FIIO is preparing the X5 which functions as a DAP and a DAC and I was sold! The downside is that it don't work with android. I guess it's only natural since it will cannibalize E18 sales. I don't understand the power supply issues thing since X5 has its own power source, so I'm still hoping that someday it will support android. Maybe with future updates?

 
BTW, Even if FIIO started to develop the X7 after the release of X5 I will definitely grab the X5 so that I won't be trapped in a viscious cycle, and I can't wait any longer!

 

[Mython]

  I was keen on buying an E17 when i learned that E18 is on its way. I thought it would be perfect for listening with my phone and watching movies with my tablet, when  suddenly after the release of E18 I learned that FIIO is preparing the X5 which functions as a DAP and a DAC and I was sold! The downside is that it don't work with android. I guess it's only natural since it will cannibalize E18 sales. I don't understand the power supply issues thing since X5 has its own power source, so I'm still hoping that someday it will support android. Maybe with future updates?

 
BTW, Even if FIIO started to develop the X7 after the release of X5 I will definitely grab the X5 so that I won't be trapped in a viscious cycle, and I can't wait any longer!

 
 
I think there are many people who are interested in X7 but will still buy X5 before X7 is released (which may be 12 - 24 months away, anyway).
 
The X5 is looking so incredibly good that it's crazy not to buy one (if you can afford it) for $350. I'm so impressed with what Fiio have achieved for such a reasonable selling price.

 

[Andykong]

   
 
Yes, I can confirmed that the specification is tested at high gain. and about the current output, it should be enough if the max output current can keep the same voltage output via low impedance driver. 

 
James, what about the output information at low gain?  is there any quick formula to work that out from the +6db gain directly?
 
I suppose the max current can only last for a fraction of a second, but when we hit the extremes such as Ray Brown's Super Bass, or Pictures at an Exhibition from Bassic Instincts, we might need hefty current that lost slightly longer then that.

 

[goldendarko]

Just curious, have there been any details on the upgrades to the X7 from the X5, as well as a price range for it? Apologies if it's already been discussed, I'm late to the thread and don't feel like reading 260+ pages of posts to get info on the X7.

 

[Mython]

  Just curious, have there been any details on the upgrades to the X7 from the X5, as well as a price range for it? Apologies if it's already been discussed, I'm late to the thread and don't feel like reading 260+ pages of posts to get info on the X7.

 
 
No, it's nothing more than an initial concept at the moment - way too early to know any details. There was a concept picture in the amateur pics from the X5-release slideshow-presentation in China, which showed a device that looked approximately like a DX100, but, AFAIK, it was nothing more than a preliminary concept pic.

 

[goldendarko]

Ok thanks Mython, X5 it will be for me then.

 

[CosmicHolyGhost]

James mentioned a while ago that they are looking at the 600-800usd price range for X7... but we need to wait until X5 becomes internationally available, X1 as well as X3 MKII (I dont know what that is) beforehand...

 

[goldendarko]

So it may be a while then, sounds like the X7 is on the back burner for now.

 

[mikroski]

   
Okay, re-did the measurement on a lower load (previously 47ohm, now half at 23.5ohm), noticed a huge drop in voltage in the same setting to suggest obvious clipping / limiting. So I lower the volume from max and confirm the voltage drop is gone which leads to two immediate observations: 1) recalculated the output impedance to around 0.4ohm under a smaller volume, which is more inline with what iBasso has claimed. The previous number is higher due to bigger voltage drop between load and no-load under max volume condition, where in both cases iBasso DX50 fails to reach the claimed 3.1V(rms?). It managed only 2.55Vrms @ 47ohm and 1.66Vrms @ 23.5ohm. Current output for DX50 dropped slightly to around 73mA (at max volume). Same 23.5ohm test to X5: voltage is holding at 2.98Vrms (from previous 3Vrms) and current output drops a bit to 288mA (from 300mA). So to the same 23.5ohm load, X5 is driving 7 times more power than DX50 (from the previous 4x @ 47ohm). There is so much power in X5's output that the dummy load actually got warmer during testing, which means X5 is capable of blowing out your headphone in the maxed-out setting, not that I'll suggest you should ever try.
 
Anyway, despite the claimed number I think it is obvious DX50 doesn't quite deliver those number under actual test. X5 on the other hand does (and quite nicely so). Your calculated number is right but those would only be true in theoretical or very ideal condition, such as a very high impedance load which will be much easy for DX50 to drive. With real world 16ohm / 32ohm headphone, it can never achieve those calculated spec. Just go to show that you can't always trust what manufacturer have said (or not said, in this case). 

Thanks for your information.
 
I have a chance to compare between my X3 and AK120 last week, using same song from my SD card and same headphones (ESW11LTD). When I play from X3, volume is 24/60. But from AK 120, I have to raise the volume to 45/xx to get the same level, don't know the maximum but it almost full scale on volume bar. I think that may be the demo AK120 that I try in shop should have some thing wrong, isn't it?
 
901 is the different story, most power and best impact for any player I have try. But for its price, I don't think it good for money