How many ohms is headphone out?

    I've read as many posts as I could find on here and tried to find the specs....but can't find out how many ohms the headphone out is. I'm looking at the




    Beyerdynamic
    DT990



    Pro and DT 880 Pro. The ones available to me online are the 250 ohm versions. I'll be playing primarily through headphones so want something that is an excellent fit. Don't want to have to spend another $100+ for a headphone amp/mixer (or pick up a cheap headphone amp and rely on it to boost the power enough).
    Thx in advance!
    Jim

    Quote from TMV

    33ohms is stated on the website. You can find that and other specs on the Kemper website under heading "did you know?"

    Perfect - thank you. I wonder what else I can find on that page I didn't know!
    I am by no means an expert in this area, but from what I've read, you would want to keep the ration of headphone out to headphone impedance at 1:8+. In other words, this would mean 33*8 or 264 ohms or more for a pair of headphones. This is not for sound volume but for sound quality. Sounds like the 250 ohm verion is fairly close. 600 ohm would be better for quality, but from what I understand, you'd lose a lot of volume...not sure if too much. I'm just using for home use (not in a band environment).
    So 250 ohm or 600 ohm....hmmmm......

    The output impedance of the headphone does not matter for sound quality.
    It is a little power amp output, where the impedance is chosen as low as possible.
    You don't have to look for a certain ratio of impedances.

    Quote from ckemper

    The output impedance of the headphone does not matter for sound quality.
    It is a little power amp output, where the impedance is chosen as low as possible.
    You don't have to look for a certain ratio of impedances.

    Thx for the reply CK - Much appreciated! So it seems like 250 ohms is a good way to go then as I understand there will be some loss of volume at 600 ohms...though I'm not sure how much of course. Also seems like the 32 ohm version of the DT880 would be unnecessarily low unless I'm missing something.
    BTW - I just ordered my Kemper today - can't wait to plug into it!
    Jim

    Quote from ckemper

    The output impedance of the headphone does not matter for sound quality.
    It is a little power amp output, where the impedance is chosen as low as possible.
    You don't have to look for a certain ratio of impedances.

    They say that headphones with higher ohms are a little bit better in sound quality for construction reasons.


    I have the Beyerdynamic DT 770 with 80 ohm. It is a good compromise for me: On the kemper it is very loud. And it is still good for use on a computer or iPhone (where the 600 ohm version would be useless (almost silent)).

    Maximum power transfer (resulting in greatest volume) occurs when the load impedance (headphones) equals the source impedance (headphone output). That does not result in the best quality but is definitely the loudest. Speakers are rated at a nominal impedance at a particular frequency but are in fact a variable impedance dependent on frequency. Using a higher impedance load assures that the variance in impedance has a negligible affect. Power transfer varies greatly with a 1:1 to 1:2 variance but not so much if the variance is 1:8 to 1:12, as an example.


    So the balance is struck between volume and flat response in the headphone design. Higher output headphone amps with lower impedance are better at creating a linear response driving high impedance headphones . The KPA's 33 ohms seems like a good design for 250 ohm or higher phones as the OP has mentioned. Of course, lower impedance phones can be designed to correct for their impedance ratio "mismatch". Only your ears (or precise instrumentation) can determine the difference.


    That's a piece of the science that is at play, as I understand it anyways. Hope this helps.


    Sorry, my techy side came out...


    bd