Well I stayed up late tonight to do some more listening. OMG these are f'ing awesome! My advice to those on the fence - just buy them, you won't be sorry.
Playlist tonight included Snatam Kaur, Hayley Westenra, Greg Laswell, Blue October all ripped with Apple Lossless. I know all their voices very well and the JH13 gets them just right. Instruments sound real. Bass fundamentals are strong without bloat in the midbass. No need for the usual audiophile descriptives, these simply get music right.
Okay it's not a fair comparison given differences in price and universal vs custom fit, but the JH13 really embarrass the Westone 3. Their tonal balance sounds totally whack in comparison, and I don't think I can listen to them any more. Hopefully my wife will like them! The Shure SE530 hold up somewhat better, but are lacking significantly at both frequency extremes and also fall short on dynamics and transparency. I'll keep them for the gym though, they err mainly in ommission, and do a respectible job with vocals.
My current setup is USB digital out from iTunes running on laptop (Dell XPS Studio 16) directly into Meier Corda Symphony.2 with the JH13 cabled plugged into the zero ohm impedance output using an adapter. The low gain setting and logarithmic attenuator allow a nice usable volume range even with the high sensitivity and there is no hiss. Maybe the perfect DAC/amp for IEM use with a PC source... particularly since I got it new from a USA dealer for just over $1,000.
Unlike my other IEMs and full size headphones (Shure SRH840) I prefer the Meier crossfeed disabled with the JH13. Imaging is stunningly good, and I never thought I'd say that about an IEM. There must be retrieval of spacial cues at the frequency extremes that are absent with other IEMs I've used. They also have more realistic soundstaging than my full size headphones (currently Shure SRH840) and my recollection of the Grado HP2 that I sold a few years ago. I find these custom IEMs much more comfortable than any full size phone. They are also more comfortable than the universals I have, used with olives and double flange tips.
I've only used the JH13 briefly with the iPhone 3gs. It seems quite respectable and totally adequate for on-the-go listening. But I notice significant improvement in transparency and dynamics with the Sympony DAC/amp, thus they do scale with amplification. But source seems paramount, the information sacrified with lossy compression is readily audible. I will be re-ripping even my 320kbps files as lossless. My 32GB 3gs just lost a lot of capacity, unfortunately! The DAC in the Symphony seems up to task, but tomorrow I'll try my (fully Aberdeen modified) Logitech Transporter with the Symphony to see how it compares. The Transporter is currently the digital source for my big rig, feeding a quad amp TacT system with digital crossovers and room correction. I haven't been using it, but its built-in DAC is supposed to be quite good stock, and this one has been upgraded substantially.
Well done, JH Audio!