Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Furnishings and Equipment (hierarchy name)
4. Tools and Equipment (hierarchy name)
5. equipment
6. [equipment by process]
7. amplifiers

Anotations

Scope note:

Direct-current amplifiers in which the signal is passed through a low-pass filter, then used to modulate a carrier signal so it may be amplified as an alternating-current signal. The amplified DC output is obtained by rectifying and filtering the carrier signal.