[Leobrioschi]

Hey guys! I just wanted to tell you my experience.

well i'm fairly new in the headfi, got interested, lurked for about 3 months, then went for a ibasso t5, Westone UM1 and an d7 sidewinder for my pc... Then i went to a q701 after a fairly long (but blindly nonetheless) "research" and i just got it... after 3 days using it i can say that i'm in love and if this is not "all mighty hi-fi" i'm probably not worthy of it.
, i'm already really pleased.  

I'm driving mine flac(foobar/wasapi) -> D7 -> q701. and absolutely love it. 
i can also drive it with my ipod mini 4th gen -> lod -> t5 -> q701. although i think the mp3s sometimes sound really terrible with it. i'm not sure going flac/alac would help but i don't pretend to use the q701 portably, it's already quite expensive to me to just roam around with it. 

i'm mainly thinking now about the pc solution. but i'm in Brazil and anything here is at least 160% of the price+shipping of the product. and for now, i'm kinda unemployed. 
i could go for a bravo audio amp next year, does it work good with the q701? anyway thanks for all your opinions (i've really spent time reading countless times this whole thread). 

 

[darkunor]

Quote:

Can Clip+ alone drive Q701 properly?
 

AKG Q701

Impedance: 62 ohms
Sensitivity: 105 dB

People always assume that the sensitivity is in dB/mW - it is not. The AKG sensitivity, like the Senns, is in dB/V. In which case the 105 dB/V @ 62 Ohms = 92.9 dB/mW. The LCD-2 is rated at 91 dB/mW, the HD650 is 96.8.

 

[wwmhf]

Quote:

People always assume that the sensitivity is in dB/mW - it is not. The AKG sensitivity, like the Senns, is in dB/V. In which case the 105 dB/V @ 62 Ohms = 92.9 dB/mW. The LCD-2 is rated at 91 dB/mW, the HD650 is 96.8.

 
My experience corroborates the above assessment about the sensitivities of Q701 and HD650. On the same amp, I need to turn the volume knob lower in order for the HD650 to have about the same loudness as the Q701.  

 

[tdockweiler]

Quote:

 
My experience corroborates the above assessment about the sensitivities of Q701 and HD650. On the same amp, I need to turn the volume knob higher in order for the HD650 to have about the same loudness as the Q701.  

 
That's weird. On my Micro Amp the HD-650 needs low gain at only 25% volume(!). The Q701 needs about 40-45%. High Gain with my HD-650 and amp would make my ears explode.
 
The K601 is much higher than both and require the volume knob to be higher than any other headphone I have (including the 600ohm Sextett I believe).
 
That's with my ODAC. When using my S580 Sony Blu-Ray player to amp, it's way higher.
 
BTW the headphone that required the most volume on the knob with my setup was the K400 (or K501). Wonder why..

 

[rrwatch]

Quote:

 
I'm not really crazy about vintage receivers.
Obviously they have no warranty.
You're dealing with a 25-35 year old piece of gear......dirty switches, dirty pots, dirty jacks, etc.
They are huge units, a bit overkill just to drive an itty bitty headphone.
They have massive output impedance, typically 220 - 470 Ohms.
 
But some folks like them........

I love some of the old behemoths I've restored. The amp in my avatar is a Pioneer SX-1000 one of Pioneer's first solid state amps. Its is so laid back and smooth. It sounds almost like a tube amp, probably made that way because folks were still used to that warm tube sound. I go over everything, no dirty pot or switches leaky capacitors ect. I use them with speakers for the most part, but some of them I've tried with HP's and they can sound pretty good. Headphones are not  new tech and some of the oldies (HPs) sound real sweet.

 

[darkunor]

Quote:

 
My experience corroborates the above assessment about the sensitivities of Q701 and HD650. On the same amp, I need to turn the volume knob higher in order for the HD650 to have about the same loudness as the Q701.  

Not sure if the higher amount of higher frequencies in the 701 makes you perceive it as louder and therefore requiring more movement on the volume knob before reaching the same perceived loudness.

 

[jasonb]

So, the general consensus is that the Q701 is actually harder to power than the HD650? Or am I getting this backwards? If this is what people are saying, I find this very hard to believe. 

 

[wwmhf]

Quote:

 
That's weird. On my Micro Amp the HD-650 needs low gain at only 25% volume(!). The Q701 needs about 40-45%. High Gain with my HD-650 and amp would make my ears explode.
 
The K601 is much higher than both and require the volume knob to be higher than any other headphone I have (including the 600ohm Sextett I believe).
 
That's with my ODAC. When using my S580 Sony Blu-Ray player to amp, it's way higher.
 
BTW the headphone that required the most volume on the knob with my setup was the K400 (or K501). Wonder why..

 
Sorry, I made a mistake in my post that caused confusion. I have changed it. 

 

[Chris J]

Quote:

I love some of the old behemoths I've restored. The amp in my avatar is a Pioneer SX-1000 one of Pioneer's first solid state amps. Its is so laid back and smooth. It sounds almost like a tube amp, probably made that way because folks were still used to that warm tube sound. I go over everything, no dirty pot or switches leaky capacitors ect. I use them with speakers for the most part, but some of them I've tried with HP's and they can sound pretty good. Headphones are not  new tech and some of the oldies (HPs) sound real sweet.

Very cool post!
 
There are people who think I am crazy because I like tube equipment (sometimes).

What can I say?
We like what we like!

 

[autoteleology]

The Q701 is much harder to drive than any of its measurements would imply, and I have no idea why. Its nominal impedance is only something like 62[size=small]Ω, and its sensitivity is nothing notable.[/size]

 

[stv014]

Quote:

The Q701 is much harder to drive than any of its measurements would imply, and I have no idea why. Its nominal impedance is only something like 62[size=small]Ω, and its sensitivity is nothing notable.[/size]

 
Measurements actually show that the K701/K702/Q701 are among the hardest to drive full size dynamic headphones:
 
K701:    Volts RMS required to reach 90dB SPL:    0.320 Vrms
K701 (another sample):    Volts RMS required to reach 90dB SPL:    0.283 Vrms
Q701:    Volts RMS required to reach 90dB SPL:    0.318 Vrms
DT880-250:    Volts RMS required to reach 90dB SPL:    0.299 Vrms
HD600:    Volts RMS required to reach 90dB SPL:    0.230 Vrms
HD650:    Volts RMS required to reach 90dB SPL:    0.205 Vrms
 
Additionally, their low impedance means that at the same voltage they draw much more current than the other headphones shown for comparison. When using a source with high output impedance, the voltage on the AKG's will drop more, too, making them quieter. On the other hand, their more mid-forward frequency response may increase the perceived loudness somewhat.

 

[Chris J]

The difference between 0.318 Volts and 0.205 Volts is 4 dB.
Not that much.
Sure, you have to turn the volume up a bit more to use Q701s releative to HD650. No big deal.
1 Volt into a Q701 works out to 105 dB SPL and 16 mWatts (going by AKGs spec sheet, they may be a bit "optimistic"!)
 
So going by the measurements, 90 dB SPL works out to 1.63 mWatts,  100 dB SPL works out to 16.3 mWatts, 110 dB SPL works out to 163 mWatts............which should cover any reasonable peak power demands.
Nothing too onerous.
 
Personally, I don't find the Q701s all that hard to drive, I've used them with an iPad tablet, I've used them with battery powered iBasso D12 and the FiiO E17.
I have no problems getting as much undistorted volume as I want.
 
YMMV

 

[stv014]

Quote:

Originally Posted by Chris J /img/forum/go_quote.gif
 
Personally, I don't find the Q701s all that hard to drive, I've used them with an iPad tablet, I've used them with battery powered iBasso D12 and the FiiO E17.

 
Most dynamic headphones are not that hard to drive. Even the DT880-600 needs only about 5 dB more voltage than the K70x (and of course a fraction of the current), but with a source impedance of 75 Ω, for example, it can even become slightly easier to drive than the AKG's.

 

[Chris J]

Quote:

 
Most dynamic headphones are not that hard to drive. Even the DT880-600 needs only about 5 dB more voltage than the K70x (and of course a fraction of the current), but with a source impedance of 75 Ω, for example, it can even become slightly easier to drive than the AKG's.

 
OMG!
The Myth Is Busted!

 

[chicolom]

Quote:

 
Personally, I don't find the Q701s all that hard to drive, I've used them with an iPad tablet, I've used them with battery powered iBasso D12 and the FiiO E17.
I have no problems getting as much undistorted volume as I want.

 
 
x2
 
They may be harder to drive than you would expect for a 62 ohm headphone, but they're not as bad as Head-fi talk will lead you to believe.