High impedance headphones problem

[MTBRiderLV]

Hello! I have ROG Phone 5s and recently purchased ROG Phone 8 pro. I have decent headphones Beyerdynamic DT770 Pro 250ohm and for 5s it wasn't a problem to drive them, but for 8 pro looks like it doesn't have enough power to drive them-they aren't as loud as on 5s and make weird sounds on max volume. I can't find any information about how high impedance it can drive.

[AndrewMcN]

I don’t have any immediate answer for you but that is quite strange because those headphones apparently only need 100mW which is nothing for a smartphone. It’s about the same as my IEM’s. That impedance is really high though. There is probably something in that, that’s causing your issue. I’d think you’d need to pursue tech support down that avenue to see if they can provide a specification on the impedance handling. It seems like it’s a powerful DAC they’ve got in there but clearly you’re encountering some kind of electrical limitation.

[MTBRiderLV]

Thanks for response. I recently found that ROG 8/8 pro has Qualcomm aqstic wcd9395 DAC, but couldn't find any specs on it. Qualcomm page doesn't list it and the highest listed is wcd9385 and it's specs says that power consumption for high performance audio is down to 29.75 mW. There is no any info about max power for headphones.

https://www.qualcomm.com/products/internet-of-things/consumer/audio/mobile-audio/wcd9385

[AndrewMcN]

Sorry I think I was talking rubbish when I said "100mW which is nothing for a smartphone. It’s about the same as my IEM’s." Most IEM's probably don't draw much more than 10mW.

I think what you want to do is find out if the ROG 5 somehow had a higher power output. That would at least explain the difference.

It seems like you might be a victim of the decreased power consumption trend. Qualcomm has sacrificed the ability to support your headphones for lower power consumption.

So, you're probably going to need a powered DAC, e.g. the FiiO Q3 or the KA17 via its balanced port and Desktop mode set to High Gain.

[kmcmurtrie]

The ROG 7 and 8 (and maybe others) don't support 300 Ohm headphones.  There's just enough output voltage for 30 Ohm headphones.

Back when all phones had headphone jacks, all the top-end models could sense impedance and adjust the output.

It might support 10K Ohm output.  The way to try it would be to plug in an extension cord, start playing, then plug headphones into the extension's jack.  I'm not sure how well that would work, if at all.