Universal Audio Apollo x4 Gen 2 (Essentials+)
A pro-tier Thunderbolt interface with 4 mic inputs, 18 outputs, loopback and phantom power, built as a desktop UAD-DSP hub. Its four Unison preamps let you track through real-time analog emulations, suiting bigger desktop sessions. It's not for Windows users lacking Thunderbolt or for budget builds — the USB Volt line is the more affordable route there.
Scores
BreakdownHideOverall75±3Caliber-forward blend — tier caliber + within-tier price rank 30%, value 25%, confidence 20%, compatibility 15%, upgrade path 10% — renormalized over applicable dimensions; excluded here: compatibility (no ecosystem dimension).
Scores
BreakdownHideCaliber-forward blend — tier caliber + within-tier price rank 30%, value 25%, confidence 20%, compatibility 15%, upgrade path 10% — renormalized over applicable dimensions; excluded here: compatibility (no ecosystem dimension).
The ± band on the overall score reflects sourcing confidence — wider when fewer specs are verified.
How each score is computed: our scoring methodology.
Specifications
| Spec | Value | Verification |
|---|---|---|
| connection | ThunderboltSourced | Sourced |
| mic inputs | 4Sourced | Sourced |
| outputs | 18Sourced | Sourced |
| phantom power | yesSourced | Sourced |
| loopback | yesSourced | Sourced |
5/5 detail specs sourced. Amber rows are flagged for verification — we show them as reported, not confirmed.
Verdict
Best for
- Desktop UAD-DSP studio with four Unison preamps for real-time emulations
Who should skip this
- Windows users without Thunderbolt; budget builds (USB Volt instead)
Where to buy
List price $1,699
Prices are a guide and can change — confirm the current price on the retailer's site before buying.
Prices last checked Jun 17, 2026 — retailer prices change often, so click through for the current price.
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Platform support
- Windows: Thunderbolt-only; requires a Thunderbolt-equipped PC
Compatibility
No platform-specific compatibility requirements — this works in any standard music production setup.
Upgrade path
Buying today, the Focusrite Scarlett 16i16 (4th Gen) scores higher for less — the smarter pick in audio interfaces unless you specifically want this one. See it →