Side by side

Internal USB 2.0 vs HD Audio front-panel headers

Intel’s Thin Mini-ITX examples use different absent-key positions (9 versus 8); a different NUC audio implementation also has another pitch. Never force a 2×5 plug by silhouette.

Computer-generated illustration, not a photograph. — P345 · ConnectorInternal USB 2.0 dual-port header — keyed 2×5, pin 9

How they differ

Internal USB 2.0 dual-port header — keyed 2×5, pin 9 Identify the missing key position using the exact board diagram; distinguish this front-panel header from USB 3.0 19-pin and USB Type-C Key-A headers.
HD Audio front-panel header — keyed 2×5 (Intel example) Look for HD_AUDIO or front-audio marking and the motherboard manual’s key location; confirm connector width and pitch rather than guessing.

At a glance

Source-scoped form facts; counts, variants and unknowns are distinct
Field	Internal USB 2.0 dual-port header — keyed 2×5, pin 9	HD Audio front-panel header — keyed 2×5 (Intel example)
Type	Connector	Connector
Family	PC internal	PC internal
Shape	two row header	two row header
Nominal contacts	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
Positions / cavity span	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
Contact rows	2 (Source-described array; C345A); 2 (B550-A PRO:JUSB1/JUSB2)S456 · S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval. B550-A PRO:JUSB1/JUSB2. Documented role: PCB header. IntelThinMiniITXRev1.2p.24USB2.0separately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.	2 (Source-described array; C346A); 2 (Source-described array; C346B); 2 (B550-A PRO:JAUD1)S456 · S457 · S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval. B550-A PRO:JAUD1. Documented role: PCB header. IntelThinMiniITXRev1.2p.21frontaudioseparately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.
Connector role	PCB header (B550-A PRO:JUSB1/JUSB2)S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. B550-A PRO:JUSB1/JUSB2. Documented role: PCB header. IntelThinMiniITXRev1.2p.24USB2.0separately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.	PCB header (B550-A PRO:JAUD1)S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. B550-A PRO:JAUD1. Documented role: PCB header. IntelThinMiniITXRev1.2p.21frontaudioseparately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.
Key distinction	A keyed header silhouette is not enough: Intel also documents a separate internal variant keyed at two positions.	Do not identify an audio header by a 2×5 outline alone; even similarly keyed HD-audio implementations can use different pitches.

Full evidence ledger and sources ↓

Illustrations are computer-generated with prior AI visual review; independent technical and rights review pending. A comparison is not a compatibility verdict.

This comparison stays within one evidence layer.

All selected records are Connector records. Similar layer does not mean compatible, interchangeable or safe to mate.

Families represented: PC internal

The reference ledger

Read the same question across.

2 selected records · 16 fields
No score. No compatibility verdict.

On a narrow screen, scroll the table sideways or open the field-by-field reading view below. Illustrations are not a size comparison.

Read field by field — no sideways scrolling

The same selected records, fields, values and source links as the table. Missing fields remain non-equivalent; no values are merged.

Layer

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: Connector
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: Connector

Key distinction

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: A keyed header silhouette is not enough: Intel also documents a separate internal variant keyed at two positions.
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: Do not identify an audio header by a 2×5 outline alone; even similarly keyed HD-audio implementations can use different pitches.

Nominal contacts

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.

Positions / cavity span

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.

Populated contacts

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.

Contact rows

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: 2 (Source-described array; C345A); 2 (B550-A PRO:JUSB1/JUSB2)S456 · S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval. B550-A PRO:JUSB1/JUSB2. Documented role: PCB header. IntelThinMiniITXRev1.2p.24USB2.0separately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: 2 (Source-described array; C346A); 2 (Source-described array; C346B); 2 (B550-A PRO:JAUD1)S456 · S457 · S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval. B550-A PRO:JAUD1. Documented role: PCB header. IntelThinMiniITXRev1.2p.21frontaudioseparately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.

Contact pitch

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: 2.54 mm Source-described pitch / centerline (Claim C345A)S456Recorded source-scoped values; named examples do not describe every family variant or establish compatibility. Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval.
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: 2 mm Source-described pitch / centerline (Claim C346B)S457Recorded source-scoped values; named examples do not describe every family variant or establish compatibility. Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval.

Dimensions / axis

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.

Connector role

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: PCB header (B550-A PRO:JUSB1/JUSB2)S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. B550-A PRO:JUSB1/JUSB2. Documented role: PCB header. IntelThinMiniITXRev1.2p.24USB2.0separately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: PCB header (B550-A PRO:JAUD1)S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. B550-A PRO:JAUD1. Documented role: PCB header. IntelThinMiniITXRev1.2p.21frontaudioseparately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.

Coupling / latch

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.

Keying / polarization

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: 10positionoutlinewithpin9absent;pin10NCnotmissing (B550-A PRO:JUSB1/JUSB2)S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. B550-A PRO:JUSB1/JUSB2. Documented role: PCB header. IntelThinMiniITXRev1.2p.24USB2.0separately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: 10positionoutlinewithpin8absent;9loadedpositions (B550-A PRO:JAUD1)S757Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. B550-A PRO:JAUD1. Documented role: PCB header. IntelThinMiniITXRev1.2p.21frontaudioseparately states2.54mmpitch;thatoldnominalscopeisretained,notremeasuredhere.; No board label,partmanufacturerorUSB/audiointerchangeabilityinferredfromsame2x5outline.

Source-scoped example

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: 2×5 footprint, one absent key at pin 9, nominal 2.54 mm (Intel Thin Mini-ITX)C345A
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: Not an equivalent field

Role and recognition scope

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: Board header — MSI B550-A PRO JUSB1–2. Original qualitative study only; no wiring or fit approval.C345C · C345D · C345E
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: Board header — MSI B550-A PRO JAUD1. Original qualitative study only; no wiring or fit approval.C346C · C346D · C346E

Intel Thin Mini-ITX reference

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: Not an equivalent field
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: 2×5, key at position 8, 2.54 mm nominal pitch in that design guideC346A

NUC counterexample

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: Not an equivalent field
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: 2×5, key at position 8, 2.0 mm nominal pitch in an Intel NUC 9 documentC346B

Evidence

Internal USB 2.0 dual-port header — keyed 2×5, pin 9P345 / Connector: C345A,C345B,C345C,C345D,C345E →
Independent review pending
HD Audio front-panel header — keyed 2×5 (Intel example)P346 / Connector: C346A,C346B,C346C,C346D,C346E →
Independent review pending

Your next step

Use the distinction in context.

Open the field notes Read source-linked facts and limitations.Compare another pair Start from a common confusion.Check a connection A comparison is not a compatibility verdict.

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Evidence behind this page

Scope first. Source second. Approval separate.

3 linked sources · 10 scoped claims · 0 sources with inspection/access flags.

Page scope: Evidence behind the compared records; the editorial comparison still needs separate review.

Assessment 2026-10-22 · earliest scheduled source review 2027-01-07. This is a recorded-date assessment, not a live source check. Page-level independent review is not established by this panel.

Inspect 3 source scopes, access limits and dates

S456 · Thin Mini-ITX Based PC System Design Guide, Revision 1.2

Intel · Manufacturer / product-owner domain · inspected 2026-10-09 · due 2027-01-07

Within inspection window

Scoped support: Explicit Intel Thin Mini-ITX examples, both documented as nominal 2.54 mm headers; not universal to all motherboards.

Not established / limitations: Original paraphrase of figures inspected visually. No Intel diagrams, pinout tables or copyrighted screenshots redistributed.

Locator: PDF page 21, §2.3.1 Fig 2-5 HD Audio 2x5 key at pin 8; page 24, §2.5.1 Fig 2-8 dual USB 2x5 key at pin 9; p25 alternate double-key variant

S457 · Intel NUC 9 Extreme/Pro Technical Product Specification

Intel · Manufacturer / product-owner domain · inspected 2026-10-09 · due 2027-01-07

Within inspection window

Scoped support: Counterexample: similar HD-audio keyed header can differ in nominal pitch by device family.

Not established / limitations: NUC 9 specific; not a basis for wiring arbitrary HD Audio headers or merging footprint types.

Locator: PDF page 28, §2.15.1 A — 2x5 audio header, 2.0mm pitch, pin 8 key

S591 · MSI B550-A PRO User Guide, version 6.0 (2024/02)

MSI · Unclassified publisher domain · inspected 2026-10-13 · due 2027-01-11

Within inspection window

Scoped support: Named B550-A PRO board header identities, diagram-level contact/key arrangements, control modes and RGB mismatch warnings.

Not established / limitations: Observed document is not a real-hardware inspection, installed-device approval, wiring guide, current revision guarantee or manufacturing specification.

Locator: PDF pp.33, 36–38, 40–41; p.59 / printed ix revision history. Source diagrams visually inspected at zero-based pages 32,35,36,37,39,40,58.

Trace 10 claims to their source records

C345A · P345

Intel’s Thin Mini-ITX design guide specifies a front-panel dual USB 2.0 2×5 header at 2.54 mm pitch, keyed by absent pin 9.

Claim scope: Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval.

Source links: S456 · Evidence trail → (private workspace)

C345B · P345

The same guide separately documents a dual internal USB 2.0 variant keyed at both positions 9 and 10; the keying must be identified explicitly.

Claim scope: Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval.

Source links: S456 · Evidence trail → (private workspace)

C345C · P345

B550-A PRO assigns JUSB1–2 to front-panel USB 2.0 ports, separately from JUSB3 and JUSB4.

Claim scope: V142: named MSI B550-A PRO manual version 6.0 (2024/02) or explicitly identified Noctua family only. Role/recognition evidence, not generic wiring, safe mating, pinout approval, dimensions or installed-device certification.

Source links: S591 · Evidence trail → (private workspace)

C345D · P345

Its JUSB1–2 table distinguishes absent position 9 from present but unconnected position 10.

Source links: S591 · Evidence trail → (private workspace)

C345E · P345

MSI warns that incorrect USB-header power/ground connections can damage equipment.

Source links: S591 · Evidence trail → (private workspace)

C346A · P346

Intel’s Thin Mini-ITX front-panel audio figure documents a 2×5, 2.54 mm header with position 8 absent.

Claim scope: Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval.

Source links: S456 · Evidence trail → (private workspace)

C346B · P346

Intel NUC 9 documentation separately specifies a similar 2×5 audio header with the same position 8 absent but a 2.0 mm pitch: the exact platform matters.

Claim scope: Manufacturer-specific family/physical identification only. No inferred device wiring, mating verification or installation approval.

Source links: S457 · Evidence trail → (private workspace)

C346C · P346

B550-A PRO identifies JAUD1 as the front-panel audio-jack connector.

Source links: S591 · Evidence trail → (private workspace)

C346D · P346

JAUD1’s table distinguishes absent position 8 from unconnected position 4.

Source links: S591 · Evidence trail → (private workspace)

C346E · P346

The JAUD1 table includes microphone/headphone detection functions; it is not a USB signal table.

Source links: S591 · Evidence trail → (private workspace)

Prepare this page for review →Read the evidence method →

Recorded evidence only. An inspection date, publisher label, source link or generated packet is not independent technical review, hardware testing, fabrication approval or a compatibility verdict.