01 · Source
8 documented inputs
¼-inch TS + XLR/TRS combo
- Arrives as
- 8 documented inputs
- Connector
- ¼-inch TS + XLR/TRS combo
- Signal
- analog audio
Audio Interface
Universal Audio Apollo x4 Gen 2
Universal Audio Apollo x4 Gen 2 Thunderbolt Audio Interface with UAD Analog Classics. Plan its source-defined physical connections and placement in your rig.
- Documented outputs
- 99 destination connections
- Documented inputs
- 8Based on documented inputs
- Rack space
- Outside rackPlan a shelf, tray, or stage position
- Power draw
- UnverifiedPower requirement is not verified in the catalog
- Catalog estimate
- ~$1,899Use retailer rows for current price and stock
01 · What it does—and what that changes in your rig.
Product overview
Start with the payoff, then work through how it functions, where it fits, and the details that change a real build.
The payoff
Audio Interface decisions, organized around the whole rig.
Universal Audio Apollo x4 Gen 2 Thunderbolt Audio Interface with UAD Analog Classics. Plan its source-defined physical connections and placement in your rig.
- Documented outputs
- 99 destination connections
- Documented inputs
- 8Based on documented inputs
- Rack space
- Outside rackPlan a shelf, tray, or stage position
02 · Know the whole path before you buy.
Signal path
Learn the route as a block diagram: source, product function, transport, and destination. Select any block to see what enters, what changes, and what leaves.
Interactive block diagramAuto-looping · hover, focus, or tap to hold a stage
Port-type signalProduct functionSystem boundary
Follow one signal from source to destination
01 · Source · selectedEach block answers the same three questions: what arrives, what changes here, and what leaves.
03 · What this product asks of the rest of the system.
Compatibility
Treat connector names as the start of the check—not the answer. These are the boundaries that determine a complete working path.
Best fit · Audio Interface
Use it as audio interface tracked outside rack rails; follow the manufacturer’s mounting and form-factor guidance.
Plan the companion path
Complete the path with upstream and downstream gear that matches connector, direction, signal type, protocol, and wiring standard.
Connector boundary
Documented connectors: ¼-inch TS, ¼-inch TRS, XLR/TRS combo, toslink. Match connector, direction, and signal type—not shape alone.
04 · Every connector, grouped by job.
I/O ports
Switch the product view and the documented port inventory updates with it—hardware and data stay side by side.
Every connector, grouped by job.
Switch panels to keep the hardware view and the documented port list in sync.
| Port | Panel | Connector | Direction | Signal | Channels |
|---|---|---|---|---|---|
| HI-Z INPUT 1 | front | ¼-inch TS | input | analog audio | — |
| HI-Z INPUT 2 | front | ¼-inch TS | input | analog audio | — |
| STEREO HEADPHONES 1 | front | ¼-inch TRS | output | analog audio | — |
| STEREO HEADPHONES 2 | front | ¼-inch TRS | output | analog audio | — |
| MIC / LINE INPUT 4 | rear | XLR/TRS combo | input | analog audio | — |
| MIC / LINE INPUT 3 | rear | XLR/TRS combo | input | analog audio | — |
| MIC / LINE INPUT 2 | rear | XLR/TRS combo | input | analog audio | — |
| MIC / LINE INPUT 1 | rear | XLR/TRS combo | input | analog audio | — |
| LINE OUT 3 · BALANCED | rear | ¼-inch TRS | output | analog audio | — |
| LINE OUT 4 · BALANCED | rear | ¼-inch TRS | output | analog audio | — |
| LINE OUT 1 · BALANCED | rear | ¼-inch TRS | output | analog audio | — |
| LINE OUT 2 · BALANCED | rear | ¼-inch TRS | output | analog audio | — |
| MONITOR L | rear | ¼-inch TRS | output | analog audio | — |
| MONITOR R | rear | ¼-inch TRS | output | analog audio | — |
| OPTICAL OUT · ADAT / S/PDIF | rear | toslink | output | digital audio | — |
| OPTICAL IN · ADAT / S/PDIF | rear | toslink | input | digital audio | — |
| THUNDERBOLT 3 · USB-C PHYSICAL | rear | usb c | bidirectional | data | — |
| 12V DC · CENTRE POSITIVE | rear | dc barrel | input | power | — |
Showing 18 of 18 documented physical ports. Scroll to review the remaining rows.
05 · Compare the decision, not just the price.
Alternatives
The rows are organized around fit, power, I/O, and system role so a cheaper unit cannot hide a more expensive workflow.
| Compare | External unit |  |  |  |
|---|---|---|---|---|
| Fit | 📐 Outside rack | 📐 1U | 📐 1U | 📐 Outside rack |
| Power | ⚡ Unverified | ⚡ 30W | ⚡ Unverified | ⚡ Unverified |
| Weight | ⚖️ 3.2 lb | ⚖️ 8.6 lb | ⚖️ 6.2 lb | ⚖️ 1.5 lb |
| I/O | 🔌 18 | 🔌 13 | 🔌 39 | 🔌 16 |
| Estimate | 💵 ~$1,899 | 💵 ~$3,799 | 💵 ~$3,199 | 💵 ~$280 |
| Deep dive | Current selection | Full comparison → | Full comparison → | Full comparison → |
06 · Resolve the questions that can change the purchase or build plan.
Planning questions
Short, source-backed answers surface rack fit, power, cabling, and connection details before they become surprises.
Where does the Universal Audio Apollo x4 Gen 2 live in a complete rig?
The catalog assigns it no rack units. Builder tracks it as non-rack gear; follow the manufacturer’s mounting, case, and form-factor guidance.
How much power does the Universal Audio Apollo x4 Gen 2 draw?
Its power requirement is not yet verified in the catalog.
What connections does the Universal Audio Apollo x4 Gen 2 have?
18 documented physical ports, including HI-Z INPUT 1, HI-Z INPUT 2, STEREO HEADPHONES 1, STEREO HEADPHONES 2, MIC / LINE INPUT 4, MIC / LINE INPUT 3.
07 · See this gear inside a complete system plan.
Builder preview
Builder keeps non-rack gear in the same bill of materials, budget, dependency, and connection plan as the rack-mounted system around it.Open in Builder08 · Related gear, in the order you may need it.
Complete the system
Audio Interface
Universal Audio Apollo x16 Gen 2
1U · 13 ports · ~$3,799Audio Interface
RME Fireface UFX III
1U · 39 ports · ~$3,199Audio Interface
MOTU M4
Outside rack · 16 ports · ~$280
Audio Interface
MOTU 16A Audio Interface
1U · 11 ports · ~$2,495
Audio Interface
MOTU 24Ao Audio Interface
1U · 9 ports · ~$1,995
Audio Interface
MOTU 24Ai Audio Interface
1U · 9 ports · ~$1,995Planning guides for audio interface systems.
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