DARKGLASS ELECTRONICS MICROTUBES 900 V2 Overheat Protection

Internal DC Brushless Cooling Fan

The Class-D power stage generates concentrated heat that requires constant forced-air convection. If the fan's sleeve bearings fail or the motor windings short, airflow ceases, causing the heatsink temperature to rapidly exceed the threshold of the thermal protection circuit.

High-Performance Thermal Interface Pad

The heat transfer between the power transistors and the aluminum chassis depends on a thermal pad or paste. Over time, thermal cycling can cause 'pump-out' or desiccation of this material, increasing thermal resistance and triggering the overheat sensor even if the fan is operational.

Speakon to Speakon 12AWG Speaker Cable

Using a thin-gauge instrument cable or a damaged speaker cable creates excessive resistance and potential shorting. This forces the amplifier to work harder to overcome the load, causing the SMPS to generate excess heat and trigger the protective mute to save the output rail.