Pedal Schematic — Blackstar Ht Dual

Blackstar’s proprietary "Infinite Shape Feature." On the schematic, this looks like a specialized tone stack that shifts the center frequency and response between "American" (tighter, scooped) and "British" (woodier, mid-forward) voicings. 🛠️ Key Schematic Sections to Study

The 12AX7 requires a specific filament voltage (usually 6.3V or 12.6V). If your pedal isn't lighting up or passing signal, this is the first place to check for a blown component. ⚠️ A Critical Warning The HT-Dual is not a beginner project for DIY repair. Lethal Voltages: The internal 300V rail can be fatal. Blackstar Ht Dual Pedal Schematic

Even when unplugged, large capacitors can hold a high-voltage charge. Blackstar’s proprietary "Infinite Shape Feature

The pedal takes 16V AC and boosts it internally to roughly 300V DC. This "B+" voltage is what allows the 12AX7 (ECC83) tube to operate in its linear region, providing real headroom. ⚠️ A Critical Warning The HT-Dual is not

The Blackstar HT-Dual is a modern classic in the world of tube-driven distortion. Unlike "starved plate" designs that run tubes at low voltages for show, the HT-Dual uses a high-voltage internal power supply to get genuine valve compression and harmonic richness.