Topic: iem vs headphone jack

I don't get certain things of the iem plug.

The manual says it is used for high-quality In Ear Monitors but it works with "portable" headphones which do not require high power or voltage? but which power? which voltage?

So, it is by all means a typical 3,5mm jack with lower noise and power, right? I have two headphones around 33ohm, are they good to be plugged in there?

Or should I use an adapter and plug those to the 6,5mm one?

2 (edited by KaiS 2020-05-07 23:50:16)

Re: iem vs headphone jack

smile Exactly! smile


Joke aside, just try what sounds best.


Without knowing what headphones you got, how loud you listen (don't!) and what music, it's impossible to give recommendations.

If you don't have to crank ADI-2 DAC's volume all up (level display set to Post FX) IEM Out is fine or even better for you.


If you like to see the power vs voltage vs load impedance diagrams:
they are in the manual page 60 for the 6.3mm plugs, figures page 52.

Conclusion: Plenty, enough to break sensitive headphones.


IEM Out, manual page 53:
• Level at 0 dBFS: -3 dBu, 0,55 V
• Signal to noise (SNR) @ -3 dBu: 118 dB RMS unweighted, 121 dBA
• Max. Power, 8 Ohm, 0,001% THD: 40 mW per channel

Conclusion: comparable level to an EU-iPhone, but much better technical quality.

3 (edited by ezra-s 2020-05-08 20:06:21)

Re: iem vs headphone jack

Thanks KaiS, I guess it is a newbie thing, I am worried about breaking anything, will try the iem plug.

PS: I miss a "like" button in this forum!

4 (edited by KaiS 2020-05-08 20:58:59)

Re: iem vs headphone jack

Your welcome, better ask now than cry later.

The ADI-2 xxx series functionality and complexity is overwhelming in the first place, even for an experienced audio pro like me.

At least, for the "DAC" the basic menu structure overview is in the manual page 9.

It's not for my "Pro", but I'm getting used to it somehow now.
I still find myself wildly pushing the buttons to find my way back to the main screen some time.

Sometimes it feels like a Sony foto camera: "You cannot do this if you set this..." because of a reason of - what?
After a while - opposed to the Sony - you start to understand the circumstances and the way the developers sqeezed every little bit out of the hardware.

Re: iem vs headphone jack

Different question on IEM out vs RCA.  At -5dbu the spec sheet shows better SNR via IEMs out.  Into Power amps at this level would the IEM out be better ? Very interested to understand the differences in the two outputs other than the plugs :-)

6 (edited by KaiS 2021-05-06 16:36:38)

Re: iem vs headphone jack

AMACB wrote:

Different question on IEM out vs RCA.  At -5dbu the spec sheet shows better SNR via IEMs out.  Into Power amps at this level would the IEM out be better ?  :-)

Yes, it can be the case that the level fits fine to a power amp, specially if you are used to listen medium loud.
It could save you from the need of external passive attenuators.


On the other hand, there are limits:

For a power amp the IEM jack’s level is still quite hot, and [post Edit, thanx MC] there is no “Auto Reference Level” function for the IEM headphones’ outputs.
-3 dbu is about 1/3 off the rated output for most power amps, i.e. 33 W with 100 W power amp, this is loud!
Additionally the IEM out’s max -3 dBu, 0,55 V cannot fully drive a usual power amplifier, most of them require ca. +6 dBu, 1.5 V and can handle music peaks of about double that value.
This means the volume control range is a bit limited if you are out for best quality.


So, finally, still it’s better to use the line out together with external passive attenuators.

Look here for how to connect and setup ADI-2 for a power amp:
https://forum.rme-audio.de/viewtopic.ph … 21#p161721

7

Re: iem vs headphone jack

> and the “Auto Reference Level” function has only two steps, high and low, for the IEM headphones’ outputs.

The IEM output does not have any Low/High power mode. So only one 'step'.

Regards
Matthias Carstens
RME