Yeah the spdif interface is modular. I couldn't decide which to go with, so I got both (with WM8805 installed by default) on Kingwa's advice. No soldering required. Just a single screw to undo after removing the case.
@ LiqTenExp - I agree with most of your impressions at this early stage. I'm only listening single ended at the moment, but it's evident this amp/dac is damn good value. The resolution, air and transparency was immediately apparent. The upper regions seem to go on forever. While I wouldn't describe it as etched or grainy though, it's missing that ultra smooth high end I'm familiar with, and I found it somewhat fatiguing with the LCD-2 rev.2 at moderate levels as a result. The HD650 on the other hand, has never sounded more lively. It reminds me of the Alessandro MS-1i's zest and energy, but with the Senn's more extended low end. Based on my experience with the FUN and testimonies from those familiar with Audio-GD components, I'm expecting burn in to make a difference.
Also, before actually hearing the Lyr fed by the SE's dac, I had already drawn the conclusion the Lyr's days were numbered in my rig. It was a pleasant surprise to find the Lyr elevated by the SE's dac and with that came the realisation my previous dac (the FUN) was a bottleneck. While both employ the WM8741, its implementation in the SE just presents more of the good stuff (weight, resolve, transparency, width, depth). The outcome here is that there are two distinct options available to me. The "reference sound" signature of the SE's amp or the less revealing but more coloured/dense/textured presentation the Lyr offers. I can't say one is "better" than the other at this stage, and again this is only single ended from the SE and without burn in. What's clear though, is that the Lyr has a place right next to the NFB-10SE. Hard to go past these two for a Swiss Army Knife rig on a modest budget.
Btw, I also agree the filters are subtle, but on some tracks the differences are quite significant (pay particular attention to vocals). In my listening session with the LCD-2 I toggled between 1, 5 and 9. I found the 4x linear phase less bright than filter 1, with more ambiance/air and slightly more forward vocals.