[castleofargh]

  Does it make sense that the Magni 2 Uber would only need the volume turned up slightly to power the 650's well?  Starting at 7 O'clcok (all the way down) and turning it up very slowly, you hear the right speaker turn on right away, quietly, and then the left speaker comes on well before you get to 8 o'clock.  By 9 o'clock, the headphones are about as loud as I'd ever want to listen.  All the way up would be 5 O'clock, and i imagine the headphones would be totally blown and ruined if I ever turned it much past 12 or 1.  Never tried as I don't want to risk it.  Does this sound weird to anyone, or normal?  

it's perfectly possible. but we would need more information to estimate how loud the hd650 is going. the DAC used(if possible the max voltage output of said DAC), if you're on full volume output both in your player and computer? if you're using replaygain or not? the kind of music you're listening to(some old stuff are recorded quite low).
or much more simple, if you have a multimeter to measure the output with a test tone.  I just tried very casually and without much care, on my ODAC O2 I have set the computer and foobar to max loudness, using replay gain(I disabled the EQ for clarity of the measurement done). I set the amp to ok loudness(not as quiet as I use for long relaxing listening, more like reasonable loudness to enjoy one or 2 songs. I end up with 0.02V, so that should be close to 69db loud @1khz into the hd650.  and I'm on gain 1X with the O2 around 8 o'clock. so with the modi low gain being X1.5, if your DAC is also around 1.5 to 2V and the knob course is similar on both amps(a lot of conjecture sorry^_^), then that seems possible indeed. I would suggest to lower your player's volume by 10 or 15db so that you can get at a more comfy position on the amp.

 

[Fearless1]

It's like the movie Beetle Juice, say the word O2 three times and up from the sound science forum he appears.....

 

[pietcux]

The HD650 is not hard to drive at all. I drive it with my Fiio E12a at times or directly out of my Sony NWZ-ZX1. And I have listened to it via the O2/ODAC combo. Nothing wrong to do that. My Asus Xonar STX can also drive it. But it sounds even better out of my Meier Audio Jazz FF or my friends Bifrost uber/ Lyr 2 stack.All the mentioned supply chains are very good, the Meier Jazz FF sounds spectacular to me. Dac in that case is the Xonar STX via line out.

 

[castleofargh]

It's like the movie Beetle Juice, say the word O2 three times and up from the sound science forum he appears.....

just like I come when someone pretends like the hd650 needs 3gigawatts to be driven properly, but there is no gossip story behind the hd650 so I'm not associated with some higher purpose by some made up correlation in that case.

I guess when someone says repeatedly something that is obviously unjustified about a device I own and know a little bit, that does make me react.
 
or maybe I'm high priest of the nwavguy cult, so I did what all nwavguy's minions do, join headfi's moderation.

day 142, they still suspect nothing

 

 

[pietcux]

just like I come when someone pretends like the hd650 needs 3gigawatts to be driven properly, but there is no gossip story behind the hd650 so I'm not associated with some higher purpose by some made up correlation in that case.:wink_face:
I guess when someone says repeatedly something that is obviously unjustified about a device I own and know a little bit, that does make me react.

or maybe I'm high priest of the nwavguy cult, so I did what all nwavguy's minions do, join headfi's moderation.
day 142, they still suspect nothing  

And you write faster than your own shadow, LOL

 

[whirlwind]

Ooops....think I will just move on to another thread....this thread seems to be moving in the wrong direction....this seems to be the norm here lately and it is getting much worse.

 

[disastermouse]

seriously? are we really going to have that argument every month? do you find legitimate to lie online to everybody about a perfectly fine device simply because you hold an unfair grudge for something that was 100% your fault? is it what you really stand for on headfi?
I took the time to explain to you how the gain worked last time. you can't even hide behind genuine ignorance anymore. I explained to you that the 6.5X gain existed on the O2 basically to use as a portable amp with an ipod's LO. the ipod was popular in the audio community at the time, and because the O2 could work as a portable amp, nwavguy decided to offer that gain setting alternative for super weak portable sources such as the ipod. you took that setting for super weak portable line outs, and plugged a desktop DAC that had between 4 and 6 times the output voltage expected with that setting! and your reaction to clipping in this scenario is to blame the O2...  :rolleyes: sure, denial is one way to deal with our mistakes.

let's take a concrete example to illustrate that perfectly dishonest idea: a USB device is made to be fed 5V, why don't you go feed 20V to 30V to all your USB devices and then come back here and blame the devices for being crap if they didn't behave like it was 5V? because that's the point you pretend to make every time you blame the O2 for clipping on the HD650 and 6.5X gain.
if the O2 had exploded or ended up broken from your misuse, you would still have been the one at fault. but that's not even the case, you mess up with the gain setting like everybody does, because there is a button and we all want to push buttons. the sound clips, you go back to the lower gain, the music is fine again. end of story.
I don't even ask you to admit your mistake, I just ask that you stop that anti O2 propaganda when the device does nothing wrong and can very much drive a hd650 at pretty unsafe loudness without clipping.(the O2 will clip at around 7V, and 4V into a hd650 is 115db loud).

Please explain to me why this was my fault. You keep saying that and you never explain why. It is a headphone amp. I used to to amp my headphones. It did so poorly.

Nothing in the marketing said the 6.5 gain was only for very weak sources at the time I bought it. A headphone amp with a setting that only works under very specific, un-marketed conditions is a design flaw. We're not talking about a high noise floor that messes with IEMs here. At least there, the amp would still amplify.

Like someone once told me 'RTFM (that doesn't exist)'. Tell me if Schiit or some other amplifier maker did this that they wouldn't be completely skewered.

 

[iancraig10]

Actually, there was a warning with mine about clipping and the high gain switch. It is supposed to be left out unless you have a weak source, such as headphone out from an Ipod. If the source is weak, it suggested putting the high gain setting, but for most things, it said leave it off since with the way that it is designed, there is a high chance of clipping.

So low gain is what it should stay on for most things fed into it.

Just offering the option of low power devices like Ipods if you want to use one, but standard feeds from line out are definitely supposed to be on low gain.

 

[penmarker]

Please explain to me why this was my fault. You keep saying that and you never explain why. It is a headphone amp. I used to to amp my headphones. It did so poorly.

Nothing in the marketing said the 6.5 gain was only for very weak sources at the time I bought it. A headphone amp with a setting that only works under very specific, un-marketed conditions is a design flaw. We're not talking about a high noise floor that messes with IEMs here. At least there, the amp would still amplify.

Like someone once told me 'RTFM (that doesn't exist)'. Tell me if Schiit or some other amplifier maker did this that they wouldn't be completely skewered.

I'm here late in the discussion, but seeing how the previous poster worded it, it seems that you're blowing things out of proportions. Now you have the knowledge about how it works, and other people know it too, so this issue shouldn't be an issue anymore. The clipping can be avoided if the user uses the amp properly. 
 
If you need it to be spelled out to you - it is your fault to use it on 6.5X gain when you should use it on a lower gain after you knew about how the gain settings work.
 
Another example is - it is the amp's fault if my speakers blow up, but it is my fault if I plugged a CD player into the amp's phono input instead of a line level input. This is because I have used the amp incorrectly.

 

[iancraig10]

To be fair, I don't think the warning about use of high gain was that prominent, but I do remember reading it when I got mine. It actually warned of clipping on high gain specifically with normal inputs and that it was just for low gain devices.

 

[disastermouse]

To be fair, I don't think the warning about use of high gain was that prominent, but I do remember reading it when I got mine. It actually warned of clipping on high gain specifically with normal inputs and that it was just for low gain devices.

I got mine in 2012. The warning needs to come in the description, not after you buy the thing.

Beyond that, I think that the HD650s are dramatically under-served by the O2.

 

[Arniesb]

I tried today Beyerdynamic a2 Amp + Chord mojo with HD650. I was ABSOLUTELY BLOWN AWAY by DETAIL, MUSICALITY, SPEED AND even SOUNDSTAGE was amazing. Almost high end Performance...

 

[ubs28]

I tried today Beyerdynamic a2 Amp + Chord mojo with HD650. I was ABSOLUTELY BLOWN AWAY by DETAIL, MUSICALITY, SPEED AND even SOUNDSTAGE was amazing. Almost high end Performance...

What difference do you hear when you use the HD 650 + Chord Mojo? (So no additional amplifier)

Or did the A2 amp did all that what you described?

 

[Arniesb]

What difference do you hear when you use the HD 650 + Chord Mojo? (So no additional amplifier)

I just gonna say A2 is better in every. Significantly better in every way... Especially in Detail retrieval, Speed and Soundstage. But Mojo amp performance is similar to my A20 in my opinion, just different signature. I personally preferr Mojo, because i like its cleaner, faster and wider signature more than A20 Romantic and a bit tubey signature.

 

[ubs28]

I just gonna say A2 is better in every. Significantly better in every way... Especially in Detail retrieval, Speed and Soundstage. But Mojo amp performance is similar to my A20 in my opinion, just different signature. I personally preferr Mojo, because i like its cleaner, faster and wider signature more than A20 Romantic and a bit tubey signature.

Good to hear. I should have my Taurus MKII shipped soon and then I'll test out how that improves the HD 650 over the Chord Hugo.