Kenwood L-A1

Kenwood's ultimate high-end audio amplifier.

Launched in a gradually vanishing market so, like many other early 1990s units, the L-A1 got barely visible and sold poorly.

The proeminent feature of the L-A1 lies in the output stages and is named Quadrive : instead of having a quadruple push-pull of power transistors driven by a single pair of predrivers, the L-A1 sports an equal amount of predrivers and output transistors.
Truly parallel quadruple push-pull, like four amplifiers in one. The benefits are a better balance between transistors, high gain, less heat dissipation and lots of current in reserve. Each of the four output transistors is rated at 120W.
There is only 420VA toroidal transformer but the L-A1 sure sounds like it holds four of them, too !

Other nice touches are the photo-coupler activated motorized volume control which uses a set of calibrated resistors instead of a resistive track (remember Sony's 1976 TA-E88B ? ;-), a steel structure made of 2mm and 4mm plates, a 5mm extruded aluminium front plate, regulated tensions everywhere, glass epoxy PCBs, relay-driven switches, a second amplifier solely dedicated to the headphones' output, a special circuit to reduce distortion to outer-space levels (Super C4 or Super Constant Current Cascode Circuit) plus a pair of XLR inputs, gold-plated brass plugs, shiny golden looks and an illuminated volume control like in the old days.
For a total of... 27kg.

The L-A1 is a rare gem, lineup-wise a bit like the KA-907 was for Kenwood at the end of the 1970s. Kenwood however proudly advertised the L-A1 as the follower, quality-wise, of the L-01A and L-02A which were launched only a decade earlier.

Interestingly enough, the L-A1 wasn't marketed in Japan under Trio's original name (Trio) but under the worldwide Kenwood.
Unfortunately, Trio's long and distinguished history in audio stopped with the L-A1.