> amplifier might need to adjust compensation
You're pushing audio, not a cable TV signal...
> For resistance you will need to limit the output voltage to ensure you’re not going over the over current limit, or you can get hurt on dynamic range for high resistance loads.
What crappy device are you plugging into a headphone jack that's even an issue? Short protection is common in most ICs.
Or, you know, use a regular headphone with an impedance between 32 an 100 ohms and that should be fine.
> crazy 3.5mm jacks there are it is inefficient to make a product that fits all
What's so crazy about it? Yes, stereo and mic inputs might be unpredictable, but for usual stereo audio it's pretty predictable
People are saying that like if most USB headphone vendor is not going to plug the cheapest DAC they could find and push whatever to the headphone.
A quick search for "high-impedance headphones" might be enlightening on this topic.
For example, Beyerdynamic offers 32, 80, and 250 ohm versions of several of their models.
> If cable length is an issue for you then you're using a really bad cable. I mean, really bad. Or have a severely underpowered output amplifier.
A cable has both resistance and capacitance, which means every cable is also a low pass filter.
If you are tuning the DAC/amplifier with power consumption as one of the criteria, then actually, yes, you will want the output power as low as possible -- which means cable length is a factor in the optimization.
Yes and you know what happens when you plug a higher impedance phone in a low impedance output right? (and the point is moot because we're talking about consumer devices)
> Headphones with impedance greater than 100 ohms are typically older or professional studio specific design
(or valve outputs - because of course it's "audiophile stuff") https://www.headphonesty.com/2019/04/headphone-impedance-dem...
> A cable has both resistance and capacitance, which means every cable is also a low pass filter.
A cable is a https://en.wikipedia.org/wiki/Transmission_line and while it is technically a low-pass filter you have to show me actual numbers to convince me that it will significantly affect, let's say > 10kHZ at usual headphone cable lengths.
This is not and has never been a problem for consumer based devices. All headphones are made +/- with the same impedance.
> Need to make sure that the DAC and amplifier don’t consume too much power yet have a good dynamic range for arbitrary cable length
If cable length is an issue for you then you're using a really bad cable. I mean, really bad. Or have a severely underpowered output amplifier.
Analog is simpler than digital. And if you think your cheap headphone will do sound better than the phone manufacturers I have a bridge to sell to you