CITATION 24 is a HARMAN KARDON product at 80s came with simple front panel but nice in audio result.
INFO AMP
Some reviewers said if this amp produces the audio power up to 100 Watts each channel for 8 Ohm loads or until 200 Watts at 4 Ohm loads.
This is an appearance of inside the amplifier.
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SCHEMATIC DIAGRAM
The Manual of amplifier here : ( LINK )
This is a result of edit and cropped schematic diagram:
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At the CITATION 24 amplifier circuit, schematic diagram are more complex than similar power amplifier schema.
Moreover, The preamp circuit must involve many transistor components.
This series of power amps belongs to the category of symmetrical amplifiers, which from the beginning to the end use symmetrical components, especially for the transistors.
The Pre Amp circuit only requires 8 transistors, while the current stabilizer in this differential amplifier uses 2 transistors each.
While the voltage amplifier circuit also uses 7 transistors, four of which are parallel connected.
Even transistors for servo bias circuits involve two complementary Darlington-connected transistors.
Its the same way with The Power Driver section, uses two SZIKLAI-connected transistors.
And finally the transistor for power amplifier uses two pairs of power transistors.
This transistor is a 2SC3907 paired with a 2SA1516.
NOTE
By using a symmetrical 56 volt power supply, it is possible for this amplifier to produce 280 watts of power at a 4 Ohm load.
In this power amplifier circuit, settings are also available for is 0 output or commonly referred to as DC Balance Adjustment.
Power transistor numbers 2SC3907 and 2SA1516 are able of producing until 130 watts of power (SOURCE).
That mean with 2 pairs of transistors will produce a maximum power of up to 260 Watts.