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LOD question I am embarrassed to ask - Page 2

post #16 of 38
Quote:
Originally Posted by Prog Rock Man View Post
An ipod contains a memory to store the music files, a DAC to convert the digital files to analogue and an amp to boost that analogue signal.

If you plug headphones into the headphone jack, or use a dock into the docking port you use all three parts of the ipod to get your signal. Volume control is with the ipod and any amp it is connected to.

If you connect to an ipod with a LOD you bypass the ipods amp only. That way you can do all the amplification and volume control with whatever amp you connect the ipod to. That can be a mini portable amp or hifi amp. Even Apple staff admit that is better than the ipods own amp.

If you connect the ipod by its docking port to a digital dock such as the Wadia itransport or Onkyo NDs1 then it bypasses the ipods amp and DAC and uses it as a memory only to store music files. Both of those docks then need to be connected to a DAC and the DAC to an amp.

Got it. I am about to assemble a semi-portable setup. I was thinking that since the Wadia is able to bypass the iPod's DAC, then there may be a connector available to plug in to the iPod that would expose purely digital output. Then I could use that as input to whatever. In the portable world though, as pointed out by ClieOS, it is not as simple as taking that output and sending it into an amp that also has a DAC, such as the 3Move. That being the case, I think I'm going to end up with the Cowon D2+ for the source, and either the P-51 Mustang or iBasso D4. (I just returned my 1 week old Triple-Fi 10 Pro's - I just cannot tolerate IEM's. )
post #17 of 38
All I can see in the future is digital docks (for want of another name) to get smaller and smaller to the point it is something the size of a LOD and that can be connected straight into a DAC. As for semi portable, here is a setup using the Onkyo and Firestone headphone amp with PSU

post #18 of 38
Sweet!
post #19 of 38
Quote:
Originally Posted by spinneresque View Post
Right... so if you are not bypassing the amplifier using the LOD, and you are not bypassing the DAC, then at what point in the ipod's processing does the LOD come in?

Am I making sense? I guess there would be the Dac's little amp plus an additional headphone amp and the Dock output cuts into the signal before it hits the headphone amp/ output?

???
I think it may have changed somewhat over the past couple of generations, but there was more electronics between the DAC and headphone out than the DAC and line out. This was a big deal around the time of the 4th and 5th generation iPods when the iMod was born, which bypassed the output caps so that higher quality ones could be used. When I tested a 5th and 6th generation iPod and my iPhone, I found that the headphone output had improved considerably. How much better the line out was in each case I couldn't test because my tediously home-made cable wouldn't work on the iPhone. I suspect though that the line-out vs. headphone out difference is considerably less with newer iPods and the iPhone though. Someone is welcome to correct me if they think I'm wrong, but my iPhone from the headphone out connected to my main rig certainly didn't sound as bad as I had expected, and certainly wasn't as bad as the 5th generation iPod I had.

Quote:
Originally Posted by Prog Rock Man View Post
All I can see in the future is digital docks (for want of another name) to get smaller and smaller to the point it is something the size of a LOD and that can be connected straight into a DAC. As for semi portable, here is a setup using the Onkyo and Firestone headphone amp with PSU

I can only wish. How do you find the Onkyo? I thought of picking one up locally.
post #20 of 38
Thread Starter 
Hey, I guess my question was not so stupid after all~!

I knew about the Wadia and the Onkyo from my earlier thread about how to bypass the ipod Dac... I just dont' get how a CHIP can extract a non dac'ed sound from the same port that dac'ed sound comes out of. I suppose that's just over my head.

For the record, I am happy with with the SQ of my rockboxed ipods (I have three of them) especially when they are amped. But what I really want is to build a Huge Capacity portable source that is 24 bit capable, allows me to choose my own Dac and my own Amp. I would rather invest in that then spend the money on the Onkyo... I guess...

My ultimate goal is to be able to carry with me at least 750GB or better 1.5 TB at a time, and have the source work in my car and with my home stereo.

The only advantage of ipod now, as I see it, is its large capacity... and for older ones, that they can run Rockbox, king of all user interfaces (.... my king, anyway. That's how much I love it.) OH and portability of course.
post #21 of 38
Quote:
Originally Posted by spinneresque View Post
Hey, I guess my question was not so stupid after all~!

I knew about the Wadia and the Onkyo from my earlier thread about how to bypass the ipod Dac... I just dont' get how a CHIP can extract a non dac'ed sound from the same port that dac'ed sound comes out of. I suppose that's just over my head.

For the record, I am happy with with the SQ of my rockboxed ipods (I have three of them) especially when they are amped. But what I really want is to build a Huge Capacity portable source that is 24 bit capable, allows me to choose my own Dac and my own Amp. I would rather invest in that then spend the money on the Onkyo... I guess...

My ultimate goal is to be able to carry with me at least 750GB or better 1.5 TB at a time, and have the source work in my car and with my home stereo.

The only advantage of ipod now, as I see it, is its large capacity... and for older ones, that they can run Rockbox, king of all user interfaces (.... my king, anyway. That's how much I love it.) OH and portability of course.

The chip is necessary because apple has the digital signal under lock and key and the chip is a authorization that allows one access to the digital signal. The chip doesn't produce the signal, just lets one get it.
post #22 of 38
Thread Starter 
Ok.... got it.

Thanks!
post #23 of 38
Quote:
Originally Posted by spinneresque View Post
I just dont' get how a CHIP can extract a non dac'ed sound from the same port that dac'ed sound comes out of. I suppose that's just over my head.
The dock has a lot of pins, only 3 of which output an analogue signal.
post #24 of 38
Hey all! This is my first post and im just getting used to the lingo and how everything works as I am new to the scene... I think im pretty good with the info in this thread save for one point....
If I were to get say the "Sony PCMD50" that was mentioned before... or any digital output device (if there even are more) could I plug it into say a "Emmeline "The Predator" Portable USB DAC/Amp" would that work as a portable setup ?

thanks!
post #25 of 38
Portable amps that have a built-in USB-connected DAC can only use the DAC if they are connected to a computer using USB. The Predator could only be connected to the Sony with an analogue connection, ie: from the headphone output. To use that Sony with a portable DAC, you'd need one that has optical input.
post #26 of 38
Alright, thanks a lot!
post #27 of 38
This thread deserves a sticky, I think it can clarify this question for alot of new people around here. I was going to ask this question myself until I found this thread
post #28 of 38
Its probably been said

but the ipod cant send a lineout signal without going through the internal amp & DAC. If it didnt there would be no sound,= All it does is deliver it to the doc (different path) instead of the headphone out at lineout volume.

Theres much debate around this but its pretty simple. I think i posted a diagram in one of the threads a few years back.
post #29 of 38
Thread Starter 
Quote:
Originally Posted by Mr_Junesequa View Post
Its probably been said

but the ipod cant send a lineout signal without going through the internal amp & DAC. If it didnt there would be no sound,= All it does is deliver it to the doc (different path) instead of the headphone out at lineout volume.

Theres much debate around this but its pretty simple. I think i posted a diagram in one of the threads a few years back.
Uh oh, so you seem to be saying that with the signal going through the dock, it bypasses the amp but not the Dac... even with the Wadia or Onkyo chip? But you mean that those devices have managed to bypass the Dac anyway, going though the dock.... because of their chips. (right?)
post #30 of 38
Quote:
Originally Posted by spinneresque View Post
Uh oh, so you seem to be saying that with the signal going through the dock, it bypasses the amp but not the Dac... even with the Wadia or Onkyo chip? But you mean that those devices have managed to bypass the Dac anyway, going though the dock.... because of their chips. (right?)
A "line out" signal = analogue, not digital.
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