600 ohms headset to use with Zaxcom recorders?

[Ugarte Sound]

Is there anyone who's using 600 ohm headset with a Zaxcom recorder? I'm thinking on getting some 2nd hand but unused Sennheiser HME26 but they are the 600ohm version and now I'm realising I've always used my Zaxcom Nova with 100ohms HD26s.

Will the headphone out of the recorder be ok with that extra impedance...? Anyone used those before on a Zax recorder?

 

Thank you

[The Documentary Sound Guy]

I can test it with my Nova for you if you give me some time, but I doubt it's a good idea.  It wasn't great with the Nomad I had.

[Rick Reineke]

   I had a set of 600 ohm AKG K240 headphones. The HP volume was adequate on my 302 but not on many other devices. I do not know about the Nova or the  HP amp specs.

[Doc Justice]

Headphone guy here. 

 

I believe the Nova has a 32Ω headphone output. There are different schools of thought that says the output impedance needs to be 1/5th to 1/8th of the nominal impedance of your headphone.

 

Since headphones have different impedances at different frequencies, you might experience big shifts in frequency response with your 600Ω headphones plugged in. It’s just not receiving the voltage necessary to drive it accurately. It won’t be a 1:1 copy of what is being recorded.

 

Electric damping factor is reduced as output impedance increases. So for 600Ω headphones, you’d likely need a 75Ω - 120Ω output to drive it.

 

Of course, this is all just what the math says and you may or may not be able to tell the difference in reality. Plug in the headphones, crank the volume enough to hear it, and see if it’s good enough for you. 

[The Documentary Sound Guy]

Just tested a Nova2 with two different 600 ohm headphones:  AKG 240 Monitor and AKG 240DF (yes, these are different).

 

Both were a bit quiet; I had to set maximum volume to get a useful mixing level.  This is normal and expected behaviour for 600ohm phones.  But if you value the ability to crank up the volume to hear the nitty gritty details, you may want to consider different headphones.  I recall it may be possible to boost the headphone output in the menu somewhere, and I didn't try this, but I recall avoiding it on the Nomad because it introduced obvious distortion.

I didn't flag any distortion or obvious frequency shifts, so it might be "good enough" for careful use.  I wouldn't discount Doc Justice's technical explanation here, it's very possible the frequencies were shifted, and I might notice more over time, but it wasn't a big enough shift that it was immediately obvious.  Your HME26 may also perform differently.  If I were guessing, I might say the low end was exaggerated, but it was hard for to differentiate the frequencies I was hearing through the phones from the music I was testing with; both the phones I tested are open back, so I was hearing some outside sound as well as the phones as well.

So, take this as a cautiously optimistic data point.  All I can say is try it and see.

[Ugarte Sound]

Great responses here thank you everyone.

I did wired my HME26s using the Audio Hi cables (there are Audio Hi and Audio Lo wiring options) and the results are encouraging. Haven't notices any big difference in freq response. Maybe something around 5dB lower than regular 100ohm HD26s. I haven't tested it thoroughly but it doesn't look bad.

 

[Ugarte Sound]

Happy to report that Sennheisers HME26 600ohms work well with Nova using Audio Hi cables (Left tip Right ring). The rest goes to the sleeve. Same for the mic cable, using Audio Hi for tip. Gain for slate mic needs to be all the way up in the Nova but level is just fine. I compared side by side HME26 600ohm vs HD26 100 ohms and I think there's something around 3-5db level difference between them but the Nova's HP out can handle it perfectly well. I feel HME26s are a tini bit less brighter than HD26, like high freqs aren't as crisp as the 26s, I guess it could be due to the Ohms difference. Also for the record "cable 7" of the optional cables for the Sennheiser HMEs/HDs is made of steel which makes it more resistant but also more stiff and worst of all much prone to get cable noise thru movement and wiggle, the transmission thru the cable to the ear cup is quite noticeable so I would not reccomend it for bag work. Leaving here this for the record