Scope

Technical timeline of the I-House Pub K-array audio system, focused on the KA34 amplifier DSP/microcontroller firmware failure and its repair. This page records dates and observable facts only. It is a working record; see Known Outstanding Issues for items not yet resolved.

The pub audio path uses K-array Kommander-KA amplifiers (KA18, KA34) driven from a Q-SYS Core 110f. See qsys-control and now-playing-system for how the audio system connects to the pub platform.


Timeline

July 2025 — Prior issues raised through official channels

  • Jul 2, 2025 — I-House help desk ticket #5384 filed, raising K-array system issues:
    • Inconsistent sound stage / poor low-frequency distribution (an additional subwoofer was proposed).
    • System tuning problems ongoing since the pub opened, including insufficient volume during large events.
  • Jul 3, 2025 — Ticket acknowledged by the help desk and escalated for management review.

May 2026 — KA34 amplifier DSP/firmware failure

  • May 19, 2026 — KA34 unit observed in a failed state:
    • Reports as raspberrypi4-64 in OsKar 2.4.9.
    • Micro version and DSP version fields blank.
    • Audio passes through, but there is no DSP parameter control via the web UI or Q-SYS.
    • Rear status light solid yellow, persisting through reboot.
    • The unit had previously been running correctly.
    • Reported to K-array official customer support requesting a microcontroller firmware flash.
  • May 20–21, 2026 — K-array support engaged. Support requested purchase provenance for the warranty/assistance chain. Provenance documentation was unavailable (facilities head consulted, unsure). K-array confirmed support would proceed regardless.
  • May 22, 2026 — Q-SYS integration testing using K-array’s official Q-SYS driver:
    • KA18 unit functional.
    • KA34 returning HTTP 500 on all /dsp/ endpoints (INPATCH, MATRIX gain parameters) and on /v2/micro/status, consistent with non-functional DSP/microcontroller firmware.
    • Debug logs retained.

June 2026 — Reflash and remote support

  • June 2026 — KA34 compute module reflashed via SD card image (oskar-image-2.4.9). Audio subsequently passing on all four output channels via Q-SYS. The IEB microcontroller firmware was still missing after the reflash (blank firmware versions in the web UI, continued 500 errors).
  • June 10, 2026 — Remote support session conducted with K-array (QuickSupport) for firmware repair.

July 2026 — Firmware restoration, preset configuration, and tuning

  • IEB microcontroller firmware restored.
  • DSP output presets configured: KU26_Natural (stage sub), KK52_Natural (banquet), GF42 / GH4 (bar right).
  • KA34 unit identity corrected to match the hardware serial (K146AS0036).
  • Sound-stage and tuning issues raised in ticket #5384 addressed through manual system tuning and sound-engineer consultation.

Configuration record

Two Kommander-KA .kamp2 configuration snapshots are available. They are not a before/after pair of the same unit:

  • old.kamp2 — configuration from the KA18 unit. Its embedded access-point name (K145AN0034) matches the KA18 serial.
  • now.kamp2 — the current configuration on the KA34 unit after reflash. Its embedded access-point name (K145AS0007) matches neither the KA18 (K145AN0034) nor the KA34’s actual hardware serial (K146AS0036). This is consistent with the SD image (oskar-image-2.4.9) originating from a different unit.

Resolved (July 2026) — unit identity mismatch. When this snapshot was captured, the KA34’s embedded serial / AP identity did not match its hardware serial (K146AS0036). This was subsequently corrected with K-array support during the IEB firmware restoration.

No configuration snapshot of the KA34’s pre-failure state exists. The section below therefore presents now.kamp2 as the current KA34 state and old.kamp2 as KA18 reference only — not as a KA34 “prior configuration.”

Both files are 8×8 DSP devices (Model 29). Routing in now.kamp2 is straight-through: input n → output n (IN1→OUT1 … IN8→OUT8).

Current KA34 output configuration (now.kamp2)

OutputPresetQtySpeaker impedanceInput routed
OUT1GF42_Natural18 ΩIN1
OUT2GF42_Natural18 ΩIN2
OUT3GF42_Natural28 ΩIN3
OUT4GF42_Natural18 ΩIN4
OUT5KU26_Natural18 ΩIN5
OUT6KU26_Natural18 ΩIN6
OUT7GH4_Natural14 ΩIN7
OUT8KK52_Natural216 ΩIN8

KA18 reference configuration (old.kamp2)

Reference only — this is the KA18 unit’s configuration, not the KA34’s.

OutputPresetQtySpeaker impedance
OUT1GF42_Natural18 Ω
OUT2GF42_Natural18 Ω
OUT3KZ14_Natural116 Ω
OUT4GF42_Natural18 Ω
OUT5KTR25_Natural14 Ω
OUT6KU26_Natural18 Ω
OUT7GH4_Natural14 Ω
OUT8KK52_Natural116 Ω

Per the Kommander-KA user guide (V2.2): firmware updates via K-Monitor and loudspeaker factory-preset output configuration are standard, manufacturer-documented user procedures. Output presets must match the loudspeakers physically connected to each output channel.


Known outstanding issues (as of July 2026)

  • One stage speaker non-functional.

The IEB microcontroller firmware restoration, DSP preset configuration, KA34 unit identity correction, and the ticket #5384 sound-stage/tuning issues were all resolved in July 2026 — see the July 2026 timeline entry.


Sources

  • old.kamp2 — Kommander-KA configuration snapshot (KA18 unit).
  • now.kamp2 — Kommander-KA configuration snapshot (KA34 unit, post-reflash).
  • KommanderKA_2RU_UG_V2_2.pdf — K-array Kommander-KA 2RU user guide, V2.2.
  • Core_110f__1C8ZVFPU8TQECQF.txt — Q-SYS Core 110f design/configuration reference.
  • I-House help desk ticket #5384 (filed Jul 2, 2025).
  • K-array customer support email thread “KA34 Firmware Flash” (May–Jun 2026).
  • Q-SYS debug logs (May 22, 2026).