[Heyyoudvd]

I don’t know why this idea that the 6XX needs an amp still gets passed around, but it’s simply not true.

Grab a 6XX and a $9 dongle from Apple. It will sound great at a very reasonable price.

 

[wantan]

An Appple dongle is unlikely to provide the power you need to drive an HD650 to a level required in studio work. Same for laptops. It also doesn't have an analog input so won't work with the Pioneer amp.

Here's a quote from diyaudioheaven:

To drive the HD650 to comfortably loud levels you only need around 1.7VRMS = 10mW into 300Ω though.
A player that is specified to reach 100mW in 32Ω thus will be able to do that job.

Read this for more detailed information:
https://diyaudioheaven.wordpress.com/tutorials/power-impedance-etc/

 

[FlyingFungus]

I don’t know why this idea that the 6XX needs an amp still gets passed around, but it’s simply not true.

Grab a 6XX and a $9 dongle from Apple. It will sound great at a very reasonable price.

I got the chance to listen to the 6XX straight from a MacBook Pro and it honestly sounded great! So agreed, I don't think an amp is necessary but I'm sure it would sound even better with one.

 

[Chris Kelly]

According to this official Sennheiser video, the HD 650 is intended to accommodate more modern music by way of a "warmer" sound. The HD 660S is intended to accommodate modern music by way of a warmer sound like the HD 650, and also accommodate today's devices by way of a lower impedance. The HD 600 is intended to reproduce the input signal as faithfully as possible, which is what I'm looking for.