Spectral & Eidolon sound good together whether with a Wadia or a whatever good source... But then, Eidolons also sounded good with Goldmund, Symphonic Line, PLinius, KR, YBA -- to name a few brands. Likewise, a Spectral was great in powering Genesis spkrs, Acapella, Tannoys, Kharma, B&W...
So, the "synergy" seems widespread! I suppose it's a matter of taste -- or what a specific dealer has in stock...:) Cheers