Kenwood KA 600 (1968–1970)

A no-nonsense, overbuilt workhorse from Kenwood's golden era. It makes 45 watts that punch like 80, and its phono stage still flirts with moving coils.

Overview

Turn the volume knob on a Kenwood KA 600 past 11 o'clock and you start to see why old-school reviewers called it "deceptively powerful." It doesn't scream or lunge. It fills the room with a dense, articulate sound that seems to come from something twice its size. There are no glowing VU meters and no chrome trim, just a slab of black steel and a row of chunky switches that clack like a bank vault. This was Kenwood's no-compromise approach to the late-'60s integrated amp: build it like a tank, spec it conservatively, and let the circuit do the talking. The mids are smooth, the bass is tight, and the highs don't fatigue, even after hours of listening. It's not as hyped-up as some of its flashier contemporaries. Put on a well-recorded jazz trio and you hear space between the instruments, texture in the cymbals, and timing that locks everything in.

The KA 600 sat just below the KA-9100 in Kenwood's lineup. It was the sweet spot for buyers who wanted flagship-level performance without the flagship price. It wasn't the most powerful amp in the lineup, and it wasn't the most feature-laden. It did offer enough power for all but the most inefficient speakers, a phono stage that could handle low-output cartridges without a step-up transformer, and a build quality that makes most modern gear feel flimsy. The chassis is thick steel, the switches are industrial-grade, and the internal layout is clean and logical. No spaghetti wiring, no cut corners. You could ship one across the country in a cardboard box and plug it in without missing a beat.

The phono stage is what sets the KA 600 apart. Most integrated amps of the era treated the phono input as an afterthought. Kenwood gave this one a fully discrete, FET-based front end with a three-position sensitivity switch: 2 mV for standard moving magnet carts, 0.5 mV for lower-output models, and a rare 0.05 mV setting that ventures into moving coil territory. That last setting is the surprise. It means you could plug in a Grado "A" or an Ortofon SL-15T without a transformer and still get a healthy signal. For 1968, that was borderline radical. The rest of the preamp section is well thought out too, with a tape monitor loop, a mono sum output (useful for AM radio or old mono records), and dual low-pass filters, one at 40 Hz and another at 80 Hz. Used together, they give a 24 dB/octave rumble cut.

Specifications

Key Features

Phono Stage with Moving Coil Headroom

Most integrated amps of the era maxed out at 2.5 mV phono sensitivity. The KA 600 offers a 0.05 mV setting, enough to handle some true moving coils without external gain. Service manuals and owner reports confirm that the circuit delivers clean gain at these levels. The FET input stage contributes to low noise and high input impedance, which reduces loading issues with delicate cartridges. It's not a dedicated MC preamp, but for a 1968 integrated it's very flexible. Even today, you can skip the step-up transformer and still get a balanced, dynamic sound from low-output carts.

Overbuilt Power Supply and Conservative Ratings

Kenwood rated the KA 600 at 45 watts per channel, but owners consistently report it driving difficult loads with ease. That points to a stout power supply and conservative engineering. The IHF dynamic power rating of 170 watts total (one channel driven) hints at serious headroom, and the massive transformer inside backs that up. Some brands inflated specs with short bursts or single-channel tests. Kenwood stuck to both-channels-driven measurements, which makes the 45WPC figure more credible. The amp doesn't clip harshly when pushed. It softens the edges instead, which makes it forgiving with less-than-perfect recordings.

Industrial-Grade Build and Serviceability

Open the chassis and you find clean point-to-point wiring, high-quality connectors, and generous spacing between components. The power supply capacitors are large, the grounding scheme is thoughtful, and the layout makes servicing easy. Later models crammed everything onto dense PCBs. The KA 600 was built for decades of use. The front panel switches are heavy-duty, the volume pot is a long-life Alps unit, and even the speaker terminals are solid brass with no signs of cost-cutting. They aren't color-coded and you need a screwdriver to use them. When properly restored, the amp can last another 50 years.

Historical Context

The KA 600 arrived in 1968, just as solid-state amplifiers were shedding their early reputation for harshness and fragility. Kenwood, like Yamaha and Sansui, was pushing what transistors could do, focusing on reliability, musicality, and conservative specs. Many manufacturers were chasing headline-grabbing wattage numbers, often using dubious measurement methods. Kenwood took the opposite approach: under-promise and over-deliver. The KA 600 competed with the Marantz 18, the Harman Kardon HK-630, and the Sansui AU-717. All were respected performers, but few matched the KA 600's combination of phono flexibility and build quality. It was also part of a broader trend, the rise of the high-performance integrated amplifier. Separate preamps and power amps were still the domain of the wealthy, but the integrated was becoming the serious audiophile's choice for value and synergy.

Collectibility & Value

Today, the KA 600 trades between $150 and $300, depending on condition and restoration status. Fully serviced units with replaced capacitors and cleaned controls sit at the higher end. Untested or cosmetically rough examples go for less. It's not as rare or coveted as a McIntosh MC240 or a Luxman L-550, but Kenwood enthusiasts and vintage audio restorers respect it for its durability and musicality. The biggest risk for buyers is aging electrolytic capacitors, especially in the power supply and signal path. If not recapped, these can lead to hum, distortion, or even transistor failure. Service technicians observe that the output transistors (typically 2SC1452/2SA755 types) are prone to failure if the bias drifts, so a proper alignment is essential after restoration. The blue incandescent input indicators are another point of failure. They are simple to replace, but often missing or broken in unloved units. When shopping, check that the phono sensitivity switch clicks positively between positions and that the tape monitor loop works without crosstalk. A clean chassis, intact rubber feet, and original knobs add value, but the real prize is an amp that has been properly recapped and biased.

Similar items on eBay

No exact Kenwood KA 600 listings are live right now — these searches show current Kenwood and similar vintage audio gear on eBay:

As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.

Related Models

• Kenwood BASIC M1 (1987-1989)
• Kenwood CM-5ES
• Kenwood CM-7ES
• Kenwood CM-9
• Kenwood JL-6100
• Braun AUDIO-1 (1965)
• Braun AUDIO-250 (1965)
• Magnavox Component Systems (1972)
• Acoustic Research AR (1967-1976)
• Acoustic Research 11