[pw55255]

Ok, but what does that +/- 7V voltage tell me? The Vpp is 14V, but in the specs chart here: http://www.headfonia.com/review-fiio-x5-second-generation-part-1/2/
it says the Max output voltage is 8.2V (peak to peak). So where is the 14V they are talking about? If anyone could explain this...

 

[T.R.A.N.C.E.]

+/- 7v (aka 14v) is what the power supply rails are operating at, as I said before, this determines what opamps can be used, and also the performance characteristics of the opamps, most opamps perform better with more power behind them, aka better sound quality.

 

[pw55255]

The opamp is what is usually called the amplifier built into the X5? Hmm, so basically it only powers the amp itself at 40% higher voltage compared to 1st gen, but it doesn't produce much higher voltage at the headphone out? Maybe you could give some more details.

 

[T.R.A.N.C.E.]

Opamps are used in many parts of the dap in X5ii, dac current conversion, low pass filter, amplification, buffer etc, in the X5ii opamps are an essential part of the dac output, line output and amp. Opamps operating at higher voltage does not necessarily mean higher power output as different opamps have different power supply requirements. All you need to know is that the higher voltage in X5ii is mainly for promoting better SQ rather than increasing power output.

 

[x RELIC x]

From what I understand, and I'll paraphrase form another amp manufacturer, 'while not automatically resulting in better sound the loudest undistorted passages are the direct result of the voltage used.' The 14V supply rails in the X5ii allows the loudest parts of the music to have plenty off headroom to be played without distortion and that with the lowest passages are what create dynamic range, and it sounds good when there is better dynamic range.

 

[x RELIC x]

I'll also point out that although they have very similar power output (mW) the X5ii has a current output of 250 mA while the first gen has a current output of 150 mA. :wink_face:

 

[T.R.A.N.C.E.]

Yep, They both have similar power output, but X5ii has higher current output, not related to the 14v voltage though, I believe the higher current output in X5ii is due to switching to the buffer BUF634.

 

[x RELIC x]

From this article, a lot of good information here:

http://www.apexhifi.com/specs.html

'In reality, headphone amplifiers also have a maximum amount of CURRENT that they can deliver. This is often the limiting factor for how much power a headphone amplifier can deliver into a low-impedance load, say, 50 ohms or lower. Power can also be calculated as P = I2 * R, where I is current (and R is impedance again).'

 

[pw55255]

Higher current output only matters with low impedance headphones, as they are more current hungry. It's now safe to assume there won't be any clipping due to exceeding max out current of the device. It doesn't matter with higher impedance cans. It's worth to remember that the amount of current results from the voltage applied. Now, what I'm wondering is why X5ii is recommended for 16-150 Ohm cans, while the 1st gen was ok for 16-300 Ohm.

 

[x RELIC x]

I believe it's just FiiO being conservative with their specs. Many users have reported driving 300 Ohm cans just fine.

 

[T.R.A.N.C.E.]

  It's worth to remember that the amount of current results from the voltage applied. 

 
Not in this instance, the BUF634 in the X5ii is a unity gain buffer, it will output 250mA current, regardless of input voltage, as long as it is within specification range.
 
Quote:

 
Now, what I'm wondering is why X5ii is recommended for 16-150 Ohm cans, while the 1st gen was ok for 16-300 Ohm.

 
I wouldn't read to much into it, probably just extra conservative rating. Going from X5ii actual specs, the X5ii will be more than capable of what the X5 was.

 

[pw55255]

I'm not saying about voltage of the battery, it's just that the Ohm law always holds. If there's more current, it has to be because of higher voltage.

 

[T.R.A.N.C.E.]

I'm not talking about the battery, I'm talking about the current output at phone out. I'm saying that the 250mA current output of X5ii has nothing to do with the higher supply voltage of 14v, the original X5 at 10v would be able to output 250mA current IF it had the BUF634 opamp like X5ii does.

 

[Wilderbeast]

Hi all,
 
Apologies if this has been asked previously - does anyone know where I can get a short coax cable to go between my X5ii and Chord Hugo? 
 
It's (very) early days yet but this little DAP could be close to the sound I've been looking for whilst traveling (Hugo is the king for home use as far as I'm concerned. I've had it more than a year now and I'm not even tempted to look around for an upgrade).
 
I've recently owned the AK120, AK120ii, iBasso DX90 & Cowon P1 and, for a variety of reasons, haven't been satisfied enough with any of them. I've been put off FiiO's DAPs because the UI and looks seem dated. I'm ashamed to say the relatively low price(s) put me off too. On a whim, and out of desperation, I took a punt on the X5ii. So far so good.

 

[Offworld42]

+-----------------------------+
|       FiiO x5ii Owners Club       |
+-----------------------------+
 
I've just joined the club...

It arrived today. microSDXC card inserted, formatted, device connected to PC, a few music folders copied over (FLAC format) .... and 'Let the Music Commence'