Release 26.8.0¶
JP150PCB 1.3Jan PřibyslavskýThis page does not apply to the product or PCB revision chosen in the header.
Released 2026-08-25 for PCB revision 1.3. Changes since release 26.7.0. Published at the time as the PDF "What's New WN-2.0"; this page is its content.
New features¶
Automatic power-down with wake-on-audio¶
The amplifier can watch for silence and drop into a lower power state after a configurable period, returning to normal when audio comes back. The feature is disabled by default.
- Target level: four levels, each switching off progressively more. Delay: 10 s to 18 h, default 30 min. Sensitivity: by default only true digital silence counts as silent; raise it if your source leaves a residual signal and the amplifier never powers down.
- Wakes on an encoder turn or press, audio returning, a SigmaStudio programmer, or any reset. The click that wakes the unit only wakes it.
- Silence is measured at the source, before the volume control. A muted power stage still being fed audio will not power down; paused audio does count as silence.
- How deep it goes depends on the selected input: USB and Bluetooth reach standby, Wi-Fi reaches sleep, S/PDIF and I2S reach power stage off, the sine generator never powers down. See Automatic power-down.
Sleep now keeps the Wi-Fi module powered¶
Sleep previously switched off the Wi-Fi module, making it electrically identical to standby and dropping the amplifier off the network. Sleep now keeps it powered, so the unit stays reachable and wakes when you play to it; standby is the only level that removes it. See Power levels.
Switch individual inputs on and off¶
Each of the six inputs can be enabled or disabled individually. A disabled input is skipped when cycling with the rotary encoder and refused over the control interface. At least one input always stays enabled; switching off the active input moves to the next enabled one. Remembered across power cycles.
Safe coexistence with a SigmaStudio programmer¶
The amplifier detects a programmer on the shared control bus within milliseconds and stands down until it finishes, so downloads and live tuning no longer need the amplifier idle or specially prepared. The level meter freezes meanwhile, automatic power-down is suspended, and a stuck bus is reported separately. See Programmer coexistence.
Clearer indication in power-down modes¶
In any power-down mode the power LED dims to a short flash every two seconds, the status LED switches off and restores on waking, and the level meter clears.
Fixed issues¶
- Volume jump when selecting the Wi-Fi input. The module reported its factory default while idle or in configuration mode. Volume now synchronises only during active playback, and the amplifier's volume wins when a source connects.
- USB audio stopped working after the computer went idle. After a host suspend the amplifier never responded to USB again until a power cycle. It now resumes normally after any suspend.
- Amplifier could stop responding if a power stage failed to start. Attempts are now time-limited and retried in the background, and a fault in one power stage no longer prevents the other from working.
- Unconfigured power stage could run loud. A power stage that cannot be configured is kept muted rather than unmuted; the amplifier retries in the background.
- Spurious hardware clipping fault in PBTL mode. The power stage is held muted and in reset from the first instruction after reset, and the supply rail comes up once and stays up.
- Wrong input after waking from sleep. The selection is re-applied automatically while the outputs are still muted.
Audio processing (DSP)¶
The standard pass-through design was streamlined and restructured, with no audible change: input and output blocks handle input selection, sample-rate conversion, metering and routing, and the main schematic has a dedicated area for your own processing. Removing eight redundant software mute stages freed about 11 % of DSP program memory.
Control interface¶
Thirteen commands added (the input enable mask, the automatic power-down policy, the I2C bus guard),
two changed (SYS:INPUT now answers; SYS:POWER:AUTO became functional). The stored settings
layout changed, so existing values were discarded once on update. See Changes by release
and Integration notes.
Known issues at the time¶
TWS pairing sometimes unstable; supply current measurement indicative only; MCLK always internal; brief digital noise when USB audio resumes after a long silence; a USB source streaming silence keeps the amplifier awake; some sources prevent automatic power-down; standby saves less power than the name suggests; on-board indicators can flicker; level metering unavailable in sleep and standby. Their current state is on Known issues.