Originally Posted by usna2016
@moses667 im really excited to hear the 500's I've been looking for an upgrade to my hd650's and have been seriously looking at them. How do you like them with the Magni?
The Magni is a pretty solid, neutral amp with more power than the 500's need (or just the right amount according to the specs). I don't really think about the Magni as good or bad, but reasonably transparent for the price. Offers plenty of power when I need it for (for example) the classical stuff that's recorded at low signal level but pops up into the high volume range now and again. But for low-dynamic range rock/pop stuff, if you don't listen too loud, you can actually get away with the 500s straight out of an iPhone; it certainly isn't ideal, but doable, so the 500s, in my experience don't demand a high-end or particularly high-power amp excepting that you might like a more non-neutral tonal flavor that a higher-end amp could offer.
BTW- When I a/b'd the 650s and 500s at the last meet, I found them almost jarringly different (not better/worse, just very different). I'd be interested to see what you make of the comparison.