I received these as a loaner to try out in the Burson Swing, so thanks Burson, really really nice to have to opportunity to try these out. I had a set of various other op-amps and will compare these as good as I can, in no particular order: NE5534 (stock): had to mention these first. I honestly think the Swing sounds stellar in its stock configuration. Bass is tight, sound is very controlled and balanced. Noise levels are good until the highest of volumes. So really, not too bad. LME49720: I had the 'HA' metal can version of these to try out. They...

I received the Burson Swing in the context of the head-fi loaner that was going on. Burson contacted me if I wanted to try it in return for a review to which I happily obliged! First, confusion. Upon looking up the Swing on Burson's site, it mentions Pre-out Output impedance as well as Head Amp Output impedance. This is a typo: the second must mean DAC out output impedance, there IS NO headphone output, out of the box. (Considering the pre-out is a cool 15 Ohm, I did use the Swing as a DAC/AMP with my HiFiman Ananda planar headphones in pre-amp...