[codeninja]

I'm using iPad, and everyone said that LOD is much better than headphone out.  While I'm waiting for my LOD, I'm using headphone out and was told that I need to use 75-90% of the max volume.  Is that mean that LOD volume level is that high as well?  If so, is it going through amplification as well to be that loud?

 

[Eric_C]

Can't answer your first question, but I can answer the second ("is it going through amplification as well to be that loud?"):
 
Yes.
Going through your headphone out means the iPad amps the signal.
The benefit of LOD is the signal is not amped by the iPad. This signal can then be amp'd by a better, external amplifier.
 
By the way, you are using an external amp, right?

 

[codeninja]

If not amplified, how can it be as loud?

 

[Eric_C]

As I said, I can't answer you first question. I don't know if the LOD signal is as loud as 75-90% volume on headphone out.
 
Please answer my question: are you using an external amp?

 

[codeninja]

Yes, I'm using little dot I+. with headphone out, I have to use 90% volume to simulate line out that I was told by David, the little dot guy.

 

[lazpete]

Can't answer your first question, but I can answer the second ("is it going through amplification as well to be that loud?"):
 
Yes.
Going through your headphone out means the iPad amps the signal.
The benefit of LOD is the signal is not amped by the iPad. This signal can then be amp'd by a better, external amplifier.
 
By the way, you are using an external amp, right?

Thats not entirely true. The amp is always in use, but the headphone output uses a sc volume control, which lowers the amplification. Putting a good volume control to 0db, or zero attenuation, is basically the same as a line out.
I do not know if the volume control on a pad is ok, but on my old ipod 5.5 running Rockbox, there is no way to hear the difference between the HP out and the LO.

 

[Eric_C]

lazpete: while I'm perfectly willing to accept that the iPod's amp may be indistinguishable from an external amp, I want to check if you're saying that the LOD doesn't bypass the iPod's amp?

 

[lazpete]

lazpete: while I'm perfectly willing to accept that the iPod's amp may be indistinguishable from an external amp, I want to check if you're saying that the LOD doesn't bypass the iPod's amp?

As far as I know, the amp is in use, but the signal does not pass the attenuation of the volume control.

 

[ljperez84]

Quote:

Quote:

lazpete: while I'm perfectly willing to accept that the iPod's amp may be indistinguishable from an external amp, I want to check if you're saying that the LOD doesn't bypass the iPod's amp?

As far as I know, the amp is in use, but the signal does not pass the attenuation of the volume control.

You may want to check that again.
 

 

[doctorx]

Using a LOD cable + PA2V2, the volume is much louder and clearer, at least on my ears.

 

[lazpete]

Quote:

You may want to check that again.
 
Explain, please?
 

 

 

[lazpete]

Quote:

Using a LOD cable + PA2V2, the volume is much louder and clearer, at least on my ears.

So, the signal is even stronger than going trought the "amped" output?
Sounds like the HP out is just lower then, by the volume control, doesnt it?

 

[BattleBrat]

The line out brings the volume to LINE LEVEL so that you can plug the Ipod into a piece of stereo equipment, similar to the output RCA's on a stationary cd player, those RCA's are brought to LINE LEVEL, it is a curtain volume level that stereo components output (it varies) 

 

[ljperez84]

Regarding the LOD does or does not bypass the amp circuit, perhaps it would be hard to prove one thing or the other unless we open an ipod to find out or get an schematic from it... 


http://forums.ilounge.com/ipod-classic-ipod-5g-video/198591-does-apples-universal-doc-bypass-ipods-internal-amp.html

I have always been from the idea it does bypass the amp circuit, since at least from me it is the whole point of having an LOD. But at the end what is important is whatever is better to your ears. 
 
 
Unless you are using a decent amp and a pair of HP that really benefit from it, you may not notice a significant diference, Currently I´m using my ipad2 with my PX-100, I don't bother connecting the LOD and E5 dongle anymore... Sounds very good straight from the HP jack,

 

[Yoga Flame]

In almost anything with a volume control, the attenuation stage comes before the amplification stage. When you turn up the volume, it's not amplifying the sound more but attenuating it less. The amount of amplification (i.e. the gain) applied to the sound is constant.
 
I've seen DAC/amps where the line out and headphone out use different opamps for their output stages. In those cases, the line out is definitely different from headphone out. But since the DAPs are pretty tight on space, I suppose it is possible for them to have just one output stage for both.
 
If the output stages in the iPad for line out and headphone out are not separate, then LOD == headphone out @ 100% volume. The existence of portable LODs suggests that this is not the case, though that's hardly a bulletproof line of reasoning.
 
On a related note, I would be interested to see documentation on whether the iPod/iPad uses pure digital attenuation (like iTunes) or digitally controlled analog attenuation (like in the FiiO E5). So far, it seems to me like it is pure digital. But I'm still not entirely sure.