Kenwood KA-3300
Seventy watts of carefully matched, direct-coupled circuitry wrapped in a chassis that weighs in at 20.9 pounds.
Overview
The Kenwood KA-3300 is a stereo integrated amplifier from what audiovintage.com calls "Kenwood's golden era of the late 1970s and early 1980s." It sits in the middle of the company's lineup. It's not a flagship, but it's not an entry-level model either. The manual, bearing the TRIO-KENWOOD CORPORATION name, is unusually precise about component selection. It promises that "capacitors, resistors and transistors are carefully matched and aligned within 1%."
The KA-3300 puts out 70 watts per channel into 8 ohms from 20 Hz to 20 kHz with no more than 0.05% total harmonic distortion. That's continuous power, not an inflated peak figure. The chassis weighs 20.9 pounds (about 9.5 kg, depending on which source you read), which suggests real transformers and substantial heatsinking inside its 16-1/8-inch wide frame.
HiFI-Stereo (September 1987, p.43) tested the KA-3300D variant and noted its full recording, playback, and dubbing connections between recorders and a selected program source—a level of tape flexibility that mattered in the late 1980s. The review also observed that the amplifier's low-frequency response changed as the control knob was rotated clockwise, which is exactly what a well-designed tone control should do.
Key Features
Direct-Coupled Power Amplifier Circuitry
The KA-3300 uses direct-coupled power amplifier circuitry throughout, so there are no coupling capacitors in the signal path. This gives tighter bass control and more stable behavior into difficult loads. The damping factor is 60 into 8Ω output impedance, which means the amplifier can grab the woofer cones and stop them promptly.
Switchable MM/MC Phono Stage with Low-Noise FET
The phono stage is where the KA-3300 punches above its mid-range class. It handles both moving magnet and moving coil cartridges through a rear-panel switch. For MC, a low-noise FET in the equalizer amplifier keeps the delicate signal from picking up hum and hiss. Sensitivity is rated at 2.5 mV for MM and 0.18 mV for MC, both into 47 kΩ. The stage accepts up to 100 mV from an MM cartridge at 1 kHz before hitting 0.05% THD, and 6 mV from an MC. That's generous headroom, so even hot pickups won't overload the input. Line inputs need just 150 mV.
Two Large Power Meters
Two large power meters flank the controls. They give real-time feedback on what the amplifier is doing, swinging with the music in a way LED bar graphs never quite matched. Watching them during loud passages also tells you how much headroom you're using before the 0.05% THD figure becomes relevant.
Separate Bass and Midrange Tone Controls with 2-Step Turnover
Instead of a single tone control, the KA-3300 has separate bass, midrange, and treble adjustments. The bass and midrange controls each have a 2-step turnover switch, which lets you shift the frequency at which the control acts. That helps when matching the amplifier to different speakers and room acoustics. You can boost the midrange without turning the upper mids into a shout, or cut the bass without gutting the lower midrange.
Subsonic Filter
A subsonic filter is built in. It cuts frequencies below the audible range that can waste amplifier power and cause woofer excursion with warped records or rumble from marginal turntables. That keeps the 70-watt rating honest, since the amplifier isn't spending energy on information you can't hear.
Signal-to-Noise at 100 dB (IHF A)
The KA-3300 has a signal-to-noise ratio of 100 dB (IHF A-weighted), which puts it firmly in the "quiet" category. The noise floor is inaudible at any reasonable listening level, with no hiss between tracks and no background hash when the music stops. HiFI-Stereo (September 1987, p.44) noted the amplifier did not become hot during testing, and found a small cooling fan located under the top cover. That's an unusual feature for an integrated amplifier.
Historical Context
The KA-3300 emerged during a period that audiovintage.com describes as Kenwood's golden era, roughly the late 1970s into the early 1980s. Japanese audio manufacturers were locked in fierce competition then, and the result was a wave of technically sophisticated, well-built components at surprisingly accessible prices. The KA-3300 combines a switchable MC phono stage, direct-coupled output, and 100 dB signal-to-noise ratio, which shows Kenwood bringing features down from its top models into the mid-range.
Within Kenwood's own catalog, the KA-3300 was positioned as a mid-range integrated amplifier. It wasn't the most powerful or the most elaborate, but it gave up little to the models above it. The manual's emphasis on matched components within 1% suggests Kenwood treated even mid-range products with care. No exact production years have been confirmed in available documentation, though the design language and the HiFI-Stereo review from September 1987 place the KA-3300D variant in active production during that period.
For collectors today, the KA-3300 offers enough power for most speakers, a phono stage that handles both MM and MC cartridges without an external step-up transformer, and build quality that has survived decades. HiFI-Stereo's test unit had a cooling fan and stayed cool during extended testing.
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