Kenwood KA 8100 - DC Stereo Integrated Amplifier (1977-79)

Smaller sibling to the KA-9100, less powerful but just as carefully built.

The x100 series was export-only : KA-9100, KA-8100, KA-7100 & KA-6100.
There is a japanese KA-8100 but it is a 1978 lower-end amp with only one transformer and more modern plastic-case transistors, visually closer to the KA-907. Two transformers, 4x 10,000µF caps and relay-protected output for the DC power supply and amp stages, voltage-regulated preamp stage, back-deported input selector and clear separation of large current / small current areas.

The phono stage is made of a 3-stage FET differential amp with current-mirror load (1st stage), Darlington circuit with current-mirror load (2nd stage) and complementary SEPP output.
The inputs are directly connected to their EQ stages of the preamp board.

Feature are galore, if not "audiophile" by todays' standards : 2-way loudness switch, high, low and subsonic fliters, dual-frequency tone controls and ±10dB input gain switch.

I believe the 2-gang logarithic volume pot to be the same as that of the KA-7300.

Being 1977, this is all metal and the D-7 rack handles were available to make you feel you did get a KA-9100 at a reduced price.

Source: http://www.thevintageknob.org/kenwood-KA-8100.html

Specifications
Power output: 75 watts per channel into 8Ω (stereo)
Frequency response: 7Hz to 50kHz
Total harmonic distortion: 0.03%
Damping factor: 50
Input sensitivity: 2.5mV (MM), 150mV (line)
Signal to noise ratio: 85dB (MM), 110dB (line)
Output: 150mV (line), 30mV (DIN), 1V (Pre out)
Speaker load impedance: 4Ω to 16Ω
Dimensions: 430 x 149 x 384mm
Weight: 14.5kg