iFi Zen Signature Setchat_bubble_outlineFrom real comments

The Zen Signature Set delivers clean, fatigue-free power that flatters a wide range of headphones. Multiple owners describe being able to listen for hours (one mentions up to three hours versus one hour on other gear) without listening fatigue. One long-time user with 11 pairs of headphones from budget to $650 says the stack makes 'any can sound great,' delivering clean power at any of its output levels without clipping or losing character, even elevating tracks they normally dislike.

XSpace and the HFM tuning add a distinctive, expanded soundstage for HIFIMAN and other headphones. One user says XSpace initially sounds edgy but becomes preferred over standard stereo, expanding the stage 'far outside your head' on orchestral material. Others confirm strong pairings with Sundara, Arya and 6XX/HD660S cans, and the bass boost is called effective and non-muddy, though a couple of users still add external EQ to dial in the low end they prefer.

Missing optical input and unclear Signature-vs-standard value are recurring sticking points. Two commenters explicitly call the lack of optical input a dealbreaker, with one saying they bought a competing Atom+ stack instead. Several prospective buyers ask whether the Signature version is worth the extra cost over the regular Zen DAC/Can, one directly stating they don't know if the price difference is worth it, while another wishes the headphone amp had a remote control.