MDSL - amp basics

el34world is a good resource for schematics

Tube triode:

• anode
• cathode
• grid (base) - controls the amount of current that flows from anode to cathode based on its input voltage
• screen (in pentodes)

Studied tube amps and tube amp basics:

1. Power mains - where the circuit usually starts on the schematics (Live, Neutral, Ground)
2. Power Transformer - Primary Coil & Secondary Coil that splits to 2/3 sections, B+ voltages (goes to power ladder), Heater coils for tubes (usually 6.6V / pin 4 & 5 of tubes), Bias adjust section, certain power for other components (if the amps have chips in its circuit)
   1. Rectifiers: Tube / Diode

3. Output Transformer: Primary is connected to power tubes (usually pentodes EL84) with Grid bias connected to main bias adjust section; Secondary is connected to speaker output
4. Phase inverter tube: usually a pair of triodes where their outputs each carry an inverted & non-inverted signal (connected to the grid of power tubes) controls the power tubes to ensure that a single signal is outputted to the speakers at a time

5. Preamp stages: contains a preamp tube / triode that is cathode-biased and can be connected to tone stacks / op-amp chips / other preamp stages (usually the grid of the concurrent preamp triode)

Solid state amps:

• Runs with ICs that are harder to configure / troubleshoot
• amps usually take smaller power (30w) to run compared to tube amps (90-120w)
• have more complicated circuits than tube amps