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# FiiO E17 "ALPEN" - First Impression + Final Thought - Page 334

Quote:
Originally Posted by feiao

as you can see from the content, the Q701 can output 120dB sound pressure when the input power is 32 mW . so E17 should drive it quite well, remember most mobile phone can only output 6 mw power.

for some hard to drive headphone, we need to check the max output voltage and the current, you can see the specification from our website www.fiio.com.cn.

The output power of E17 is 220mW at 32 ohms, so the power should be about 110mW at 64ohms, still bigger than 32mW. and the max peak output voltage of E17 is 7.3Vp-p , max output current is 80mA.

So it should drive Q701 quite good. of course, it is just for reference, and this is just based on a person who have average hearing.

What does the peak voltage and max current mean in that chart?

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Quote:
Originally Posted by jasonb

So it only takes .10MW to get to 96db on the Q701? One tenth of a MW to get to 96db?

What does peak voltage and max current mean in that chart?

Yes, it means 0.1mW can get to 96dB on Q701. but the impedance 62 ohms is tested in 1K hz, it will increase to about 100 ohms, see below. so the power demand C will be more reasonable.

Since the power is calculated depend on impedance, so the best way is judged by the peak voltage ( for high impedance ) or max output current ( for low impedance ) .

Do remember that high impedance headphones need high voltage, but low impedance headphone need more current.

Quote:
Originally Posted by feiao

Yes, it means 0.1mW can get to 96dB on Q701. but the impedance 62 ohms is tested in 1K hz, it will increase to about 100 ohms, see below. so the power demand C will be more reasonable.

Since the power is calculated depend on impedance, so the best way is judged by the peak voltage ( for high impedance ) or max output current ( for low impedance ) .

Do remember that high impedance headphones need high voltage, but low impedance headphone need more current.

Still not understanding what the peak voltage column and the max current mean on that chart. Is it the voltage and current needed to get them to 120db?

Quote:
Originally Posted by jasonb

Still not understanding what the peak voltage column and the max current mean on that chart. Is it the voltage and current needed to get them to 120db?

Bingo!

BTW, I really need someone who has electronic background so he can help me explain it more detail to the reader. anybody help?

I only listen at about 75-80db, so I'm really using very little power. Nice to know. How many MW does it take to get the Q701 to 80 DB?

Quote:
Originally Posted by feiao

Bingo!

BTW, I really need someone who has electronic background so he can help me explain it more detail to the reader. anybody help?

Quote:
Originally Posted by jasonb

I only listen at about 75-80db, so I'm really using very little power. Nice to know. How many MW does it take to get the Q701 to 80 DB?
how do you know you are listen at 75-80dB?

I got Fiio L7 line out adapter today from mp4nation.

I connected L7 to E17 and it makes a very disturbing background hissing noise.

I tried turning bypass on and off but no difference.

It plays music fine but background hiss is very disturbing. Is there a solution?

Quote:
Originally Posted by dsan

I got Fiio L7 line out adapter today from mp4nation.

I connected L7 to E17 and it makes a very disturbing background hissing noise.

I tried turning bypass on and off but no difference.

It plays music fine but background hiss is very disturbing. Is there a solution?

In addition, I can connect my headphone straight to line out port of L7 and it plays well.

Is this normal? I thought line out was not suppose to output sound because it doesnt have a filter or amp (it does for e17 but I thought amp is bypassed when L7 is used)

Even if it can get enough power isnt the end. I got a plateaud signal yesterday on very similarly powered E07K with Q701. It clipped and plateaud basically.
Quote:
Originally Posted by kalbee

Don't touch the glass/plastic tip with your skin. If you must, do it with the back of your nail (after making sure it's decently clean). When not using the cables, make sure you put the cover back on. Well, for optical cables that is, they always come with caps/covers.
What about letting my cat lick it? Apparently they have very hygenic tongues! Or is it dogs?
Quote:
Originally Posted by McNuggetsPie

Up to how many ohms headphones can it drive? It is enough for Q701?

You will have no trouble driving a pair of Q701 with an E17.
I normally leave the gain at 0 dB and turn the volume up and down, depending on the source and the music I am listening to.

I do not get good results driving my 600 Ohm Beyers wit the E17.
Quote:
Originally Posted by jasonb

What does the peak voltage and max current mean in that chart?

The voltage listed in those charts is Volts peak to peak.

Divide by 2 to get peak voltage.

Then divide by square root of 2 to get Volts rms, which is the number you are really looking for.

For E17: 7.3 Volts peak to peak works out to 2.58 Volts rms.

So what does this mean?
The Q701 requires 1 Volt rms for 105 dB SPL. Note: This is 16 mW.
2.58 V rms is 8.2 dB louder than 1 Volt.
Maximum SPL you can get from the Q701 driven from an E17 is 105 + 8.2 = 113 dB SPL per channel.

So there is enough output Voltage available to drive a pair of Q701 to very loud volumes.

I am not sure if the maximum current on the charts is Amps peak or Amps rms.

Volts rms X Amps rms = Watts continuous. (some poeple erroneously refer to this as Watts rms).
Edited by Chris J - 12/14/12 at 9:12am
Quote:
Originally Posted by bowei006

One does not simply clean a cable like that

There are ways and they are availble online, but not touching them would be better than cleaning them in most cases. That is of course they don't fall in mud.

Cleaning them leaves residue that the human eye can not see. The glass or clear part is very small and its clear making it harder for the already hard residue to be seen.

Will The One Ring help us clean optical cables?

Or is this a skill even beyond the Power of the Elves?
Edited by Chris J - 12/14/12 at 4:50am

.

Edited by FLACvest - 2/27/14 at 12:28pm
Quote:
Originally Posted by jasonb

Still not understanding what the peak voltage column and the max current mean on that chart. Is it the voltage and current needed to get them to 120db?

Those numbers define the maximum voltage and current available from the various FiiO products.

If you need to kmow whether a particular FiiO product can drive your phones to a skull splitting 120 dB SPL, you also need either efficiency or sensitivity rating of your phones.
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