Objective2 Mini-Review and Discussion

[nsk1]

So did anyone compare this to anything? If not here, maybe on diyaudio?

 

[Reticuli2]

Oh you are?  Why?

 

[Shike]

Oh you are?  Why?

Higher voltage output - no reason to use the LOD IMO.

 

[Reticuli2]

Line outs perform better as line outs usually.

 

[Twinster]

Now, we can read the creator (NwAvGuy) of the O2 on Innerfidelity site. Well done!

 

[Shike]

Line outs perform better as line outs usually.

If you need a lower constant voltage regardless of volume sure. There isn't anything horrible about using the ipod headphone out as a preamp in this case though. The O2 can handle it more than well enough.

 

[Reticuli2]

Most headphone jacks I've measured tend to perform worse as line outs than the line out they are being fed, though they perform better as line outs than they do as headphone jacks.  The only exception has been higher impedance headphone jacks that seem to perform about the same in either use.  Not sure why electrically that would be the case.  I would think, assuming the ipod has under 8 or 16ohms on the jack, its line out would perform better.  Otherwise, isn't the O2 acting more like a low impedance buffer and current booster and it's the iPod that's doing all the voltage amplification?  I know iPods distort after a certain voltage into headphone loads.  I assume they wouldn't do that driving a line in, but still, the O2 probably does a better job.  Since the iPod internally has a fixed line level feeding a headphone amp, I would just assume this line level in combination with the O2 will have higher performance.  Maybe not?

 

[Shike]

Quote:

Most headphone jacks I've measured tend to perform worse as line outs than the line out they are being fed, though they perform better as line outs than they do as headphone jacks.  The only exception has been higher impedance headphone jacks that seem to perform about the same in either use.  Not sure why electrically that would be the case.  I would think, assuming the ipod has under 8 or 16ohms on the jack, its line out would perform better.
 
The ipod output impedance is roughly 30 ohms iirc.
 
Otherwise, isn't the O2 acting more like a low impedance buffer and current booster and it's the iPod that's doing all the voltage amplification?
 
The ipod is performing some voltage amplification.  Think of a DAC going to an IV stage or preamp, then to an amp.
 
I know iPods distort after a certain voltage into headphone loads.  I assume they wouldn't do that driving a line in, but still, the O2 probably does a better job.  Since the iPod internally has a fixed line level feeding a headphone amp, I would just assume this line level in combination with the O2 will have higher performance.  Maybe not?
 
The O2 would need a gain of 12 to reach the same amplification level, I really didn't want to mess with a gain the high.  Let's say I get away from the ipod in the future and the next player does not have a line-out.  Now I have to decrease the digital volume and dynamic range available to get it to work since most are ~1V.  That is a bad trade-off in comparison IMO.  I don't know whether the line-out into a gain of 12 would be better, but if it is I doubt it would be significant.
 
Sounds like something to ask NwAvGuy though

Replies in bold.
 

 

[DarkSleip]

Well, 30 ohms don't provide for enough damping with 32 or 26 ohm headphones, henceD in those cases it would be sensible to use the o2 from the Lo

 

[upstateguy]

Bump because we lost the other O2 thread to the Sound Science forum.

 

[uelover]

 
Quote:

The ipod output impedance is roughly 30 ohms iirc.

 

 
Receiving my O2 soon. It is somewhere along the Pacific Ocean.

 

[SLCanhead]

Please, be sure to let me (those who are curious) know how it mates with your D7!
 
Quote:

 

 

 
Receiving my O2 soon. It is somewhere along the Pacific Ocean.

 

 

[uelover]

Quote:

Please, be sure to let me (those who are curious) know how it mates with your D7!

I no longer have my D7. I have sold it away in exchange for an O2

 
The D7 is like a mini-replica of my desktop setup, very nice indeed. I hope that the O2 will work well with my desktop DAC on my custom iem to make the parting of my D7 more bearable. =)

 

[SLCanhead]

Makes sense. Sorry to hear about your "loss", but from the way it sounds I am sure you will get over it

...
 
I guess I may have to be the first, then!
 
Quote:

I no longer have my D7. I have sold it away in exchange for an O2

 
The D7 is like a mini-replica of my desktop setup, very nice indeed. I hope that the O2 will work well with my desktop DAC on my custom iem to make the parting of my D7 more bearable. =)

 

 

[DarkSleip]

If you don't wan't to part with anything just do it yourself. It's not so hard, you know?