[Lil' Knight]

^ oh, that's horrible PP drama...

I have a couple of boards right here but haven't got chance to find the parts. Wallwarts are dirt cheap here, something like $3/ea, and I can pick up locally.

 

[mikeaj]

 
Quote:

you can head over to diyaudio.com. there's currently a pcb group buy over there, but i'm not sure whether it's closed or not

 
Ah thanks, I was just curious though.  I was already on the group buy at diyaudio. 

 

[maverickronin]

I've got a short (by my standards anyway...) review posted here if anyone's interested.

 

[chinesekiwi]

Quote:

I think Mr.Slim offers the O2 for a very good price! And it is great to be of the first people getting a completely new design from the very educated inventor of the O2.

NwAvguy is the inventor, Mr. Slim is just offering his services for a build. Anyway, same here

 

[arirug]

Yeah! I know NwAvguy is the inventor, but I thought I was not allowed to mention his name here  

 

[Willakan]

Well, the GB is now well over 500 boards - 620 to be precise...

 

[svyr]

wonder if this can handle K340 (360ohm, 94 dB / mW) or K240DF (600ohm, 88 db/mW)... without horrible distortion, at high enough volumes or fr sags...

 

[Soaa-]

wonder if this can handle K340 (360ohm, 94 dB / mW) or K240DF (600ohm, 88 db/mW)... without horrible distortion, at high enough volumes or fr sags...

Should handle the K 240 DF just fine. FR sags only occur with low impedance headphones and/or high internal impedance amps, and this is the opposite case. Distortion only occurs when there isn't sufficient voltage swing, and in this case, there is. I don't think the K 240 DF will be much of a problem.

 

[svyr]

Should handle the K 240 DF just fine. FR sags only occur with low impedance headphones and/or high internal impedance amps, and this is the opposite case. Distortion only occurs when there isn't sufficient voltage swing, and in this case, there is. I don't think the K 240 DF will be much of a problem.

interesting... i heard pretty odd things from amps near peak output, trying to drive k340 (fr wise)... But anyway, 240DF is harder to drive, so if the amp can take it, then it can take both

 

[Willakan]

Output power for the O2 is an ample 613mW at 33 ohms, but drops to 355mW at 150ohms. Looking at your headphones, you'll have absolutely no issues with the K340 - that only needs about 120mW worst case. With the K240 you'll be fine with most recordings, but could conceivably have problems with quieter recordings at higher volumes - but nothing ReplayGain can't fix.
 
EDIT: Strikes me this amp would get on wonderfully with the LCD2s. Plenty loud with prettymuch anything and power to spare...

 

[svyr]

Output power for the O2 is an ample 613mW at 33 ohms, but drops to 355mW at 150ohms. Looking at your headphones, you'll have absolutely no issues with the K340 - that only needs about 120mW worst case. With the K240 you'll be fine with most recordings, but could conceivably have problems with quieter recordings at higher volumes - but nothing ReplayGain can't fix.

Thanks. Well, I no longer have either, just curious, since those two are the most power hungry dynamic HP I know of (HE6 ortho is probably more so, but I'm not sure). I always shoot myself in the leg with the old classical music dvds... no replay gain there lol. (vol leveling plugins, or vanilla gain via eq i spose)

 

[Armaegis]

Quote:

Output power for the O2 is an ample 613mW at 33 ohms, but drops to 355mW at 150ohms. Looking at your headphones, you'll have absolutely no issues with the K340 - that only needs about 120mW worst case. With the K240 you'll be fine with most recordings, but could conceivably have problems with quieter recordings at higher volumes - but nothing ReplayGain can't fix.
 
EDIT: Strikes me this amp would get on wonderfully with the LCD2s. Plenty loud with prettymuch anything and power to spare...

I've owned a few K340s and tried them out on numerous amps and receivers of all price points. Most of them had ample power, but very few sounded good with them and the K340 is still a weird and difficult headphone to drive. I have no beef against the O2, but I would hesitate to make the statement that it can drive such and such based purely on the numbers. 
 

 

[Soaa-]

I've owned a few K340s and tried them out on numerous amps and receivers of all price points. Most of them had ample power, but very few sounded good with them and the K340 is still a weird and difficult headphone to drive. I have no beef against the O2, but I would hesitate to make the statement that it can drive such and such based purely on the numbers. 
 

The K 340 is an oddball, being dynamic/electret dual driver cans. Expected performance can be extrapolated for simple configurations such as the K 240 DF though.

 

[mikeaj]

Actually I think the designer would say that the K240DF is at the fringe or outside the range of the O2.  You can only get 7.3V rms out (88 mW) on AC power into 600 ohms, at 1% THD; more like 7V rms (82 mW) if you're expecting it to maintain low THD like under 0.01%. 
 
So with either figure that's about 107 dB SPL with 88 dB SPL / 1 mW headphones.  NwAvGuy mentions 110 dB SPL as the target, though that's very debatable.

 

[SpaceTimeMorph]

Another review posted, for those curious: http://www.head-fi.org/t/571317/small-objective-2-review#post_7746496