Multi-page diagrams showing every resistor, capacitor, transistor, and tube. This includes the power supply, preamp, phase inverter, and the unique transformer-tapped output stage.
H&K often used double-sided, through-hole PCBs. The service manual provides a top-down map showing exactly where R117 or C23 sits. Without this, tracing a broken trace is nearly impossible. hughes and kettner statesman service manual
Tube amplifiers contain lethal voltages. Even when unplugged, large filter capacitors can store hundreds of volts for days. Multi-page diagrams showing every resistor