Do we really need headphone amps for IEMs?

[urfaust]

Last week i sold my headphone amp for some reasons so before getting a replacement i had just the dac to listen to music on my desktop (D30pro) and out curiosity i plugged in my IEMs directly to the DAC on the outputs. I tried both RCA and XLR with a little adapter. To my surprise SQ was stunning, i could even say better than with the amp and i had a lot of power to play with, like the DAC at -0dB in "pre mode" i couldn't really go past 40 or 45 on the windows volume (or vice versa), it was extremely loud already, more than i could handle past that on Tidal and other music apps. I could totally live with that SQ and power.

So my question...is it because the D30pro has a pre mode? or is it because it has low output impedance per the official specs : 20 Ohm on RCA, and 40 on the XLR (i couldn't really tell the difference between the two both plenty of power, fidelity and no detectable background noise/hiss or FR shift. What would happen if say the DAC had 100 Ohm of output impedance instead like the D90Se or even higher with a Gustard X16?

I would just like to understand how and why, and if in the cases of IEM that have low impedance usually and high sensitivity (most of mine are in the range of 20-30 Ohm) do we really need an amp.

 

[maverickronin]

Which IEMs? There are a bunch in your sig.

If they are sensitive enough and have a flat impedance curve then the low current and high output impedance of a line out won't really make much of a difference.

 

[urfaust]

Which IEMs? There are a bunch in your sig.

If they are sensitive enough and have a flat impedance curve then the low current and high output impedance of a line out won't really make much of a difference.

Tried them all, levels vary but they are all usable in this configuration with serious driving power. I would say the Mangrid gets the most, at 25%, it's already quite loud.

 

[Vini darko]

This one time a bacterium coughed and my iem's popped - true story

 

[urfaust]

On the flipside, this is crazy but if for no reason i plug those IEMs to my motherboard output (that is supposed to be amped), sound is anemic and terrible with very noticeable noise background, as they are very sensitive (could blind test this all day). Same on the headphone output of the TV (absolute garbage while it's a flagship panasonic oled). I know we are talking trashes solutions here from an audiophile standpoint but the actual point is, we, I need a dac, but im not sure anymore i need an amp (in this case of course)

 

[sarumbear]

On the flipside, this is crazy but if for no reason i plug those IEMs to my motherboard output (that is supposed to be amped), sound is anemic and terrible with very noticeable noise background, as they are very sensitive (could blind test this all day). Same on the headphone output of the TV (absolute garbage while it's a flagship panasonic oled). I know we are talking trashes solutions here from an audiophile standpoint but the actual point is, we, I need a dac, but im not sure anymore i need an amp (in this case of course)

Last week i sold my headphone amp for some reasons so before getting a replacement i had just the dac to listen to music on my desktop (D30pro) and out curiosity i plugged in my IEMs directly to the DAC on the outputs. I tried both RCA and XLR with a little adapter. To my surprise SQ was stunning, i could even say better than with the amp and i had a lot of power to play with, like the DAC at -0dB in "pre mode" i couldn't really go past 40 or 45 on the windows volume (or vice versa), it was extremely loud already, more than i could handle past that on Tidal and other music apps. I could totally live with that SQ and power.

So my question...is it because the D30pro has a pre mode? or is it because it has low output impedance per the official specs : 20 Ohm on RCA, and 40 on the XLR (i couldn't really tell the difference between the two both plenty of power, fidelity and no detectable background noise/hiss or FR shift. What would happen if say the DAC had 100 Ohm of output impedance instead like the D90Se or even higher with a Gustard X16?

I would just like to understand how and why, and if in the cases of IEM that have low impedance usually and high sensitivity (most of mine are in the range of 20-30 Ohm) do we really need an amp.

just use active IEMs

 

[urfaust]

just use active IEMs

What do you mean by active IEM?

Btw i compared with the apple dongle that i have too, which was rated here in the review at 31mw @ 33 ohm, so the DAC alone is definately producing more than that. It's difficult to say exaclty but trying to level match i would say at least two times based on win incrementation. If it gets close to 100mw it would be alright with a lot of gears that have low impedance.

 

[sarumbear]

What do you mean by active IEM?

Btw i compared with the apple dongle that i have too, which was rated here in the review at 31mw @ 33 ohm, so the DAC alone is definately producing more than that. It's difficult to say exaclty but trying to level match i would say at least two times based on win incrementation. If it gets close to 100mw it would be alright with a lot of gears that have low impedance.

Active IEM is an IEM which doesn’t need an amplifier, i.e. like wireless.

 

[maverickronin]

Tried them all, levels vary but they are all usable in this configuration with serious driving power. I would say the Mangrid gets the most, at 25%, it's already quite loud.

A couple of those look like they are multi-way with BAs and those almost always have wild impedance swings, so it's likely altering the frequency response somewhat, but they are usually also ludicrously sensitive, so you'll likely have all the power you need. The output impedance on the D30 Pro is also fairly low for a line out, which would help with both as well.

On the flipside, this is crazy but if for no reason i plug those IEMs to my motherboard output (that is supposed to be amped), sound is anemic and terrible with very noticeable noise background, as they are very sensitive (could blind test this all day). Same on the headphone output of the TV (absolute garbage while it's a flagship panasonic oled). I know we are talking trashes solutions here from an audiophile standpoint but the actual point is, we, I need a dac, but im not sure anymore i need an amp (in this case of course)

Those usually have very high noise floors. They could also be capacitor coupled with the caps sized for a load in tens of kiloohms causing the bass to roll off with IEMs which usually have low impedance at bass frequencies.

 

[amirm]

Your issue here is high impedance of RCA and XLR outputs from DACs. That causes significant losses in low impedance IEMs. And can vary the frequency response of any that doesn't have a flat frequency response. There is also a risk of overdriving the output stage of the DAC but that risk is low.

 

[urfaust]

Your issue here is high impedance of RCA and XLR outputs from DACs. That causes significant losses in low impedance IEMs. And can vary the frequency response of any that doesn't have a flat frequency response. There is also a risk of overdriving the output stage of the DAC but that risk is low.

Specs of the D30p say 20 ohm on the RCA, would that change the behavior of the IEM? I could not detect it myself compared to its usual frequency response (on the Mangrid for example). Im not sure it translates in same fashion as those higher impedance jack plugs, tilting the frequency response downward right (more bass/less high), i have one that adds 30ohm and i can tell right away, not with the DAC alone. At what point of a dac's output impedance do you think it could really become noticeable?