I don’t typically listen at really high volumes because I have good hearing for my age and I’m paranoid about Noise Induced Hearing Loss. I usually listen to music in the 70–85 decibel range in general use. In a headphone review, I will crank things up for the briefest period or use a highly dynamic track to check volume performance, then spend most of my tests at my normal listening levels, which I think reflect “standard” use for most folks too.
The 80ohm DT770 is built to have high power handling capability, which makes it a good match for studio equipment like mixing boards and high end audio interfaces. If you push a lot of juice through it the driver won’t break up in the same way as the other two models. The very small materials/construction difference is also what gives the 80 ohm version slightly more oomph in the sub bass region. But they all have more or less the same sound performance.
The 32 ohm version will still get a bit louder out of a lower-powered source.
If you’re really into high volume listening, you probably will want an amp. In all three cases you’ve mentioned, with a standalone amp…you’ll actually be “double amping” since your iPhone, PC, and receiver all already contain their own headphone amps. Sometimes double amping can cause weird impedance problems or reveal hiss/noise/other issues that aren’t audible when just listening directly on your source. That’s why a lot of folks either plug straight into their device’s headphone jack, or use a DAC and amp together or DAC/amp combo unit in order to give their amp the cleanest possible source.
The best way to figure all this out is to get the headphones first, try them on your sources, and see what you think!
If things seem too quiet or messy-sounding, then consider investing in more equipment. Otherwise you’ll be fine. I ran an 80ohm 770 off of a 12-inch MacBook for several months without any issues.
Thanks for reading.