when I was deciding on which Yggy flavor to choose I found super best audiofriends (though I don’t post there as there is lower tolerance there for noobs and general inquirers). OTOH I’ve found the user comparison ‘quality’ there pretty good- and useful for those of us who can’t afford to own multiple of these devices to compare. Below is info I gleaned from there NOT including MIB - as I was making my decision before MIB came out. But there is a similar thread on the MIB, see post above on pages 774-775 of this head-fi thread for more info. I won’t comment on the wisdom or o/w of producing/selling the different flavors- other than that their stated reason is to provide an internal upgrade path for those who have invested in their most expensive products without the user needing to buy an entirely new DAC.
ALL of this was based on user impressions not measurement rigs —as usual YMMV
CHARTS
Engagement / microdynamics / immediacy
Plankton / low-level information / resolution (not macro-detail)
Blackground / clarity
Richness (entire range, not necessarily warmth, think chocolate cakeness)
Treble F'kery (digititus, sandiness, unnatural edge, prickliness)
BAL OUTPUTS / AES INPUT and variety of headphones and amps
RANKINGS
Plankton:
Goes like this: Gungnir A1 = Bifrost 2 <= LIM = Yggdrasil GS/A1 <= Gungnir A2 < Yggdrasil A2/OG
For "blackground" and clarity:
Gungnir A1 = Yggdrasil A1/GS < Gungnir A2 = Yggdrasil A2/OG < Bifrost 2 <= LIM <= MIL
Harmonic richness (throughout entire range, not to be confused with outright warmth)
Yggdrasil A1/GS = Gungnir A1 < LIM <= Gungnir A2 <= Bifrost 2 = Yggdrasil A2/OG
Engagement/microdynamics/expressiveness/immediacy (again, splitting hairs as usual):
BF2=MIL < A2/OG < LIM < DAC2541