[jamato8]

Deleted. 
 
Measurements all look good, difference but I look forward to listening impressions. 

 

[SilverEars]

 

 


 

 

[SilverEars]

I think the DX90 and X5 are neck and neck except distortion, which DX90 has less, and X5 has more power.  I'm not totoally sure, but DX90 square wave looks the best, and X5 is the next best.

 

[hkppl]

According to that Chinese link, the graphs show that DX90 wins in almost any aspect compared with DX50/X3/X5...
 
Also someone in that link said it would be better to use the LO and add an amp in order to get better SQ from the DX90, just like the AK series...

 

[SilverEars]

DX50 definitely measures the worst among the 4.  I don't know why they didn't include the FR graph and square wave of DX100.

 

[M-13]

Wait... why is the voltage only 2.1Vrms?
 
Shouldn't it be 2.8Vrms like the X5 and X3?
 
147mW into 32ohms, while being okay is much lower than stated by Ibasso. I was thinking it would do 250mW+ like the X5 since they're both rated at 2.8Vrms.
 
(Is this DX90 perhaps just a beta-test unit or something?)

 

[headwhacker]

Wait... why is the voltage only 2.1Vrms?

Shouldn't it be 2.8Vrms like the X5 and X3?

147mW into 32ohms, while being okay is much lower than stated by Ibasso. I was thinking it would do 250mW+ like the X5 since they're both rated at 2.8Vrms.

(Is this DX90 perhaps just a beta-test unit or something?)

I don't read chinese, but possible it's set to mid gain?

 

[thegunner100]

  Wait... why is the voltage only 2.1Vrms?
 
Shouldn't it be 2.8Vrms like the X5 and X3?
 
147mW into 32ohms, while being okay is much lower than stated by Ibasso. I was thinking it would do 250mW+ like the X5 since they're both rated at 2.8Vrms.
 
(Is this DX90 perhaps just a beta-test unit or something?)

Maybe it was set it medium gain? That would make sense as medium gain is rated 2.0Vrms

 

[M-13]

I don't read chinese, but possible it's set to mid gain?

  Maybe it was set it medium gain? That would make sense as medium gain is rated 2.0Vrms

I REALLY hope that's what it is. And you guys are right, that's the most logical explanation.
 
For reference on the Ibasso site it says:
 
Output Level: 1.3Vrms(Low gain), 2.0Vrms(Mid gain), 2.8Vrms(High Gain)
 
So if it was on medium gain then it exceeds the specifications, if it was on High, then...

(calling on our Chinese members for clarification please, thank you)

 

[ClieOS]

  I think the DX90 and X5 are neck and neck except distortion, which DX90 has less, and X5 has more power.  I'm not totoally sure, but DX90 square wave looks the best, and X5 is the next best.

 
You are somewhat right. The number looks better on DX90 for the most parts but when it comes to full output, you can see X3 and X5 can comfortable max out (and almost double the output) and still has THD under 1%. Basically it means DX90 should have the advantage as long as you don't push it outside of its comfort zone. The further you push it, the more X5 will catch up, and overtake when near / over 150mW is needed. But with that much power into 32ohm, DX50 should be just fine with most headphone out there.
 

  Wait... why is the voltage only 2.1Vrms?
 
Shouldn't it be 2.8Vrms like the X5 and X3?
 
147mW into 32ohms, while being okay is much lower than stated by Ibasso. I was thinking it would do 250mW+ like the X5 since they're both rated at 2.8Vrms.
 
(Is this DX90 perhaps just a beta-test unit or something?)

 
iBasso stated it can do 2.8Vrms, but it is not that same as saying it is the maximum undistorted output. It is the 1% THD threshold that matters. Gain setting doesn't have much to do with it directly. What the measurement means is that you keep pushing the volume (and gain) higher and higher until you hit the 1% mark (or you max out on volume and gain, like X3 / X5 in this case). The 1% mark is chosen because it is believed that that is the point when distortion becomes audible to human ears. So basically it is a test to show the maximum power you can get into a certain load until you start to distort the sound audibly.

 

[jamato8]

All I know from listening is that I can run the DX90 at max volume and I hear no distortion and the sound quality doesn't really change from when the volume was lower. I wonder if they tested it correctly. I trust iBasso more than what is shown there for output because I have heard the output into the TH900 and the HE-560. 

 

[M-13]

   
iBasso stated it can do 2.8Vrms, but it is not that same as saying it is the maximum undistorted output. It is the 1% THD threshold that matters. Gain setting doesn't have much to do with it directly. What the measurement means is that you keep pushing the volume (and gain) higher and higher until you hit the 1% mark (or you max out on volume and gain, like X3 / X5 in this case). The 1% mark is chosen because it is believed that that is the point when distortion becomes audible to human ears. So basically it is a test to show the maximum power you can get into a certain load until you start to distort the sound audibly.

I see, so what you're saying is that if the tester maxes the volume of the DX90, then it will be 2.8Vrms, but with higher than 1% THD?
 
Does it say what volume he used before reaching 1%?
 
Hmm... I guess the X5 does have an advantage for harder to drive cans that need closer to max volume.

 

[SilverEars]

I see, so I'm thinking X3 and X5 would perform better at high volume for more demanding headphones.
 
The FR graphs, at what load is that?

 

[M-13]

  All I know from listening is that I can run the DX90 at max volume and I hear no distortion and the sound quality doesn't really change from when the volume was lower. I wonder if they tested it correctly. I trust iBasso more than what is shown there for output because I have heard the output into the TH900 and the HE-560. 

So from your subjective impression, would you say the DX90 is just as powerful as the X5 in driving all those cans? Or a little less? Because according to this tester the X5 is like 48% 25% more powerful which seems just wrong, unless he was using medium gain or something.

 

[headwhacker]

I REALLY hope that's what it is. And you guys are right, that's the most logical explanation.

For reference on the Ibasso site it says:

Output Level: 1.3Vrms(Low gain), 2.0Vrms(Mid gain), 2.8Vrms(High Gain)

So if it was on medium gain then it exceeds the specifications, if it was on High, then... (calling on our Chinese members for clarification please, thank you)

It must be. The DX50 is also at the same level at 1.7Vrms (1.612Vrms) for mid gain.