Hi Jeff, That's a good and especially honest review. However, there is one major mistake. ;) Hiss is not related to output impedance. There are devices with high output impedance that have no hiss at all whereas here are high OI devices that are darn hissy. And not all devices with low output impedance are automatically hiss-free - hiss and OI are two totally different things. Probably something you could (and should) change in your review.