[ClieOS]

Just came back home and thought I'll give both Tanchjim Sapce and W4 a quick measure. Both are under the same 47ohm dummy load, max volume. Note, we are only looking at max voltage here (and its associated power), and ignoring that the distortion could very well affect the actual rated power)

Space:
3.5mm: 0.69V x 95mA = 65.55mW (USB Power Draw 0.72W)
4.4mm: 1.38V x 107mA = 147.66mW (USB Power Draw 1.18W)

W4 (High Gain)
3.5mm: 0.68V x 87mA = 59.16mW (USB Power Draw 0.72W)
4.4mm: 1.31V x 149mA = 195.19mW (USB Power Draw1.07W)

As you can see, W4's 3.5mm has actually no advantage over Sapce's 3.5mm when both are maxed out. It offers a tiny less volume and power. On the 4.4mm, however, even though W4 actually has less volume, it gives more power because of more current. So here is a situation where you don't always get more volume even where there is more power.

 

[Reader]

Just came back home and thought I'll give both Tanchjim Sapce and W4 a quick measure. Both are under the same 47ohm dummy load, max volume. Note, we are only looking at max voltage here (and its associated power), and ignoring that the distortion could very well affect the actual rated power)

Space:
3.5mm: 0.69V x 95mA = 65.55mW (USB Power Draw 0.72W)
4.4mm: 1.38V x 107mA = 147.66mW (USB Power Draw 1.18W)

W4 (High Gain)
3.5mm: 0.68V x 87mA = 59.16mW (USB Power Draw 0.72W)
4.4mm: 1.31V x 149mA = 195.19mW (USB Power Draw1.07W)

As you can see, W4's 3.5mm has actually no advantage over Sapce's 3.5mm when both are maxed out. It offers a tiny less volume and power. On the 4.4mm, however, even though W4 actually has less volume, it gives more power because of more current. So here is a situation where you don't always get more volume even where there is more power.

Headphone sensitivity are db/mw, voltage should not be the only thing affect volume, as it would against law of physics. Further if an amp can do high enough voltage but unable to supply the current, the result should not be higher volume but clipping.

Edit: just thought of something, music usually have crest factor of 20 db. So by supply higher voltage at max vol setting, space simply has more gain, and for most part of music that does not stress the amp, the space would play it louder, but when something like demanding bass hit and volume is at absolute max, it would not able to supply the current/power to keep play the music as it should, or as least not as well as the W4.

This could explain the lower perceived volume despite having more power.

So either Space is to aggressive with it's gain or W4 is too conservative. My money is on the former.

 

[ClieOS]

Headphone sensitivity are db/mw, voltage should not be the only thing affect volume, as it would against law of physics. ...

That's not entirely correct. Some manufacturers do express a headphone's sensitivity by dB/mW but some manufacturers also use dB/mV.

 

[Reader]

That's not entirely correct. Some manufacturers do express a headphone's sensitivity by dB/mW but some manufacturers also use dB/mV.

That is true, but when they use db/mv it's assumed amp would able to supply enough current for the given voltage and impedance.

 

[Reader]

Headphone sensitivity are db/mw, voltage should not be the only thing affect volume, as it would against law of physics. Further if an amp can do high enough voltage but unable to supply the current, the result should not be higher volume but clipping.

Edit: just thought of something, music usually have crest factor of 20 db. So by supply higher voltage at max vol setting, space simply has more gain, and for most part of music that does not stress the amp, the space would play it louder, but when something like demanding bass hit and volume is at absolute max, it would not able to supply the current/power to keep play the music as it should, or as least not as well as the W4.

This could explain the lower perceived volume despite having more power.

So either Space is to aggressive with it's gain or W4 is too conservative. My money is on the former.

Read ASR review again and yes, that's the case, review says volume should be kept at lower than -2 click on the Space, the amp simply can't supply clean power to max volume.

 

[Polky74]

W4 + iHA-6 + HD800S = Perfect Synergy

 

[Reader]

W4 + iHA-6 + HD800S = Perfect Synergy

You using W4 as dac and iHA-6 as amp? But since W4 has more than enough power to drive HD800s(it does over 55mW to 300ohm and HD800s is 102 dB/mW), add an amp would only increase the noise and distortion and gains no benefit.

 

[Polky74]

You using W4 as dac and iHA-6 as amp? But since W4 has more than enough power to drive HD800s(it does over 55mW to 300ohm and HD800s is 102 dB/mW), add an amp would only increase the noise and distortion and gains no benefit.

The added noise is practically imperceptible by connecting everything balanced and the way in which the HD800S are driven by the iHA-6 compared to how the W4 drives them alone is like comparing day to night. It's not just a question of numbers and quantity of current to calculate, but of authority, control, tone, power reserve, in addition to all this the Cayin is a practically transparent amplifier so it brings you everything from the W4 to the HD800S, even the most small nuances. If it were as you think, two amplifiers of equal power would drive any headphones/IEM in the same way, but this is not the case. If you have a quality balanced amplifier and quality headphones you can try and see if it drives them like the W4 or not.

 

[Andrew_WOT]

You using W4 as dac and iHA-6 as amp? But since W4 has more than enough power to drive HD800s(it does over 55mW to 300ohm and HD800s is 102 dB/mW), add an amp would only increase the noise and distortion and gains no benefit.

W4 amp is only good at properly driving IEMs and may be few portable high sensitivity phones like Sony MDR-1AM2.
Big guns need big amps.
Disagree? Try it for yourself.

 

[Polky74]

@Andrew_WOT I read that Taurus is in your signature, have you tried connecting the W4 to it?

​

 

[areek]

Yes, S1 and W2.

 

[Andrew_WOT]

@Andrew_WOT I read that Taurus is in your signature, have you tried connecting the W4 to it?

​

Never thought of trying as have Auralic Vega DAC paired with that.
But as you asked, curiosity got the best of me.
Listening HE6SE (hardest phones to drive in my stash) right now on W4 through Auralic Taurus.
Oh, boy, the whole setup is ridiculous, but it sound stupendously good, could not imagine that W4 is THAT resolving and I am only using SE output.

 

[Polky74]

Imagine that I bought the iHA-6 specifically for them...

And then, this is the cable that works the miracle...

https://it.aliexpress.com/item/1005...st_main.5.21ef3696kyctzC&gatewayAdapt=glo2ita

 

[Reader]

W4 amp is only good at properly driving IEMs and may be few portable high sensitivity phones like Sony MDR-1AM2.
Big guns need big amps.
Disagree? Try it for yourself.

I have both HD800s and W4, with stock 4.4 balanced cable into W4's 4.4 balanced output it can drive HD800s with all the dynamic and headroom I want even with EQ.

I notice zero difference between W4 and my A90 combo with HD800s.

 

[Reader]

The added noise is practically imperceptible by connecting everything balanced and the way in which the HD800S are driven by the iHA-6 compared to how the W4 drives them alone is like comparing day to night. It's not just a question of numbers and quantity of current to calculate, but of authority, control, tone, power reserve, in addition to all this the Cayin is a practically transparent amplifier so it brings you everything from the W4 to the HD800S, even the most small nuances. If it were as you think, two amplifiers of equal power would drive any headphones/IEM in the same way, but this is not the case. If you have a quality balanced amplifier and quality headphones you can try and see if it drives them like the W4 or not.

I have both HD800s and HE6 SE. When using HE6SE everything you said is true, W4 simply can't power it. But with HD800s I really don't hear any difference between W4 and A90 combo.