[Magic77]

Just wondering what others might think about this one. I'm not against external supplies, but I prefer there to be an internal one with an IEC connection. This eliminates having to upgrade to a better power supply and spending more money. For example; the Shiit Audio products and the Meier Audio products all have internal power supplies with an IEC connection. Not to say that an external makes an amp's performance any worse, i guess it's just my own personal preference.

 

[NA Blur]

The highest quality signals are going to be from well isolated power supplies.  If you drop a poorly isolated power supply near audio components you are going to get noise.  There is no way around it.  With an external power supply you can reject a ton of this noise and feed a more pure voltage signal into the audio components.  This is another reason why separate amp, DAC, and power supplies are often better sounding than ones with all three combines.  There are of course devices that do well with internal power supplies, but if you take the same device and use the same power supply externally the noise has to be lower.
 
I use the Grace m903 which utilizes an internal power supply.  They admit that the m903 over the m902 has a lower noise power supply, but they mention the noise on the PSU.  Read more about that here:
http://www.head-fi.org/t/521166/grace-design-m903-reference-headphone-amplifier-dac-monitor-controller/15
 
I know the Ultra Desktop for example has its own default power supply which is a Astrodyne power supply.  That is a great power supply, but even Headroom offers an upgrade on an already stunning power supply.  Getting clean and isolated power to any audio components is key to maintaining a clean signal.  If you start off with a poor signal or source it is going to be very hard to correct it or make it sound better down the line.
 
I say if you have the space and budget go with an external power supply.
 
What gear are you planning on using?  Please list your headphones / speakers and the amp needs.