Yamaha CA-1000 (1973)

Name: Yamaha CA-1000
Brand: Yamaha

Yamaha's first try at Class A in a solid-state world, and it got noticed across the Japanese high-end.

Overview

The CA-1000 is the amplifier where Yamaha started building a reputation. Released in 1973 for ¥98,000, it arrived when nearly every solid-state amplifier on the market ran Class B and nothing else. Yamaha's answer was a stereo pre-main amplifier that switched between Class A and Class B operation: 15 watts per channel of pure Class A into 8 ohms, or up to 70 watts per channel in Class B, both channels driven across the full 20 Hz to 20 kHz band. The switch wasn't a gimmick.

It's two amplifiers in one chassis. In Class A, the CA-1000 delivers 15W + 15W at 8 ohms with total harmonic distortion of 0.1% or less at rated output, dropping to 0.02% or less at 1 watt. Flip to Class B and you get 70W + 70W at 8 ohms (or 85W + 85W at 4 ohms), with THD of 0.1% or less at rated output and 0.04% or less at 1 watt. Dynamic power in Class B, measured to the IHF standard, is a claimed 200W into 8 ohms. The power bandwidth runs from 5 Hz to 100 kHz in Class A and 5 Hz to 50 kHz in Class B. A damping factor of 70 at 1 kHz into 8 ohms and a signal-to-noise ratio of 100 dB (IHF, A-weighted) finish off the main amplifier's spec sheet.

Class A in a consumer amplifier was rare in 1973. thevintageknob.org notes that switchable Class A/Class AB modes were among "the rarities which very few other japanese makers had put in their top amplifiers in 1973."

Key Features

Class A / Class B Switching

The power stage switches between Class A and Class B, giving the listener a choice between Class B's stable power and Class A's low distortion. The main amplifier section is a pure complementary OCL circuit, directly connected through all stages with no interstage capacitor. The bias stabilization circuit uses two differential amplifiers and transistors, with an FET in the bias circuit of the first differential amplifier. According to thevintageknob.org, the "current steering" circuit lets the output pairs stay in Class A for currents up to twice the bias current, with the power supply lowered to ±26V and bias current increased to 0.5A.

SRPP FET Phono Stage with MC Capability

The equalizer amplifier uses an SRPP-type FET in its first stage. A high supply voltage of +50V and a SEPP output stage with low output impedance give high output at low distortion. The equalizer network combines metal-coated resistors with ±1% tolerance and styrene capacitors with ±1% or ±2% tolerance. The Phono 1 circuit has an input impedance selection switch to match cartridge loading, plus a built-in head amplifier for moving coil cartridges, so no step-up transformer is needed. Phono 1 offers 200μV sensitivity at 100 ohms for MC, or 3mV at 50k/100k ohms for MM. Phono 2 is fixed at 3mV/50k ohms for MM. Thevintageknob.org notes the phono stage sits right after the terminals, as far from the power supply section as possible, and that Phono 1 has a semi-floating ground circuit better suited to MC cartridges while Phono 2 bypasses the additional preamp for MM use.

Massive Power Supply

The power supply has a large-core power transformer with excellent regulation, dual 18,000μF capacitors, and a high-capacity rectifying diode rated for 250A surge current. Thevintageknob.org describes the transformer as a 270VA unit with the capacitors rated at 80V. A separately set constant voltage power supply drives all stages except the power stage. Power consumption is rated at 250W nominal, 420W maximum.

Two-Stage Protection Circuit

The CA-1000 has two protection circuits: one for the power transistors and one for the speakers. The power transistor protection operates in microseconds against overload. Even if the load drops below 2 ohms or the output terminal is short-circuited, the circuit responds instantly. It's an input limiter type, so output only decreases while protection is active and playback isn't interrupted. The speaker protection circuit triggers when DC voltage at the output exceeds ±2V, cutting the signal path via relay right away. It resets automatically when voltage falls back within ±2V.

Continuous Loudness and Flexible Tone Controls

The tone control circuit is a three-stage direct-coupled amplifier with Yamaha's mixing NF and CR types. In the Tone Defeat position, the circuit operates as a flat amplifier. Bass control offers ±15 dB at 50 Hz; treble offers ±10 dB at 10 kHz. The loudness circuit is continuously variable and follows an equal loudness curve, so it isn't a simple on/off switch. Filter circuits provide low cutoff at 20 Hz or 70 Hz (12dB/octave) and high cutoff at 6 kHz or 12 kHz (6dB/octave), each switchable between two stages.

Pre-Main Coupler and System Flexibility

A pre-main coupler lets the preamplifier and main amplifier sections be used separately. The unit includes audio muting at -20dB. Inputs cover Phono 1 (MC/MM), Phono 2, MIC (2.5mV/50k ohms), Tuner, AUX 1, AUX 2, and Tape PB A and B, all at 120mV/40k ohms. Pre-out delivers 775mV at 2k ohms; Rec-out provides 120mV at 2k ohms. The phono stage's maximum allowable input is 310mVrms (870mVp-p). Frequency response for the phono stage holds RIAA deviation to ±0.2 dB from 30 Hz to 15 kHz.

Componentry

The CA-1000 uses six FETs, 55 transistors, and five Zener diodes. Thevintageknob.org notes the use of 1% tolerance metal film and styrol resistors, three-stage DC shelving tone controls, and a fully differential power stage driver with current mirror.

Historical Context

The CA-1000 arrived when early solid-state amplifiers in Class B ruled the market, and Yamaha went back to basics with Class A. According to thevintageknob.org, it was "the first of a very long line of very successful, very reliable and very heavy amplifiers which sold like hotcakes until the mid 1980s," and "japanese high-end-wise, the CA-1000 is the example everybody else quickly followed."

The model remained available until the launch of the CA-1010, known as the CA-1000 III in Japan, depending on whether a given market saw the intermediary CA-1000 II. The family line continued with the CA-1000 II, CA-1010, and CA-2010. Yamaha had entered the component stereo market in 1972 with the CA-700 and CA-500, and the following year began a completely different integrated amplifier lineup. The CA-1000 was the flagship of that new direction.

Original pricing was ¥98,000 at release in 1973. By February 1976, the list price in the United States was $600; in France, 3,790 FF as of March 1976.

Collectibility & Value

Collectors have picked the CA-1000 up for its history and build quality. Recent eBay sales data shows a median price of $748, with completed sales ranging from $365 to $1,338 over the past 12 months. The high water mark sits at $1,897, while the low is $197, likely a unit needing restoration. Sales volume runs approximately two per month. Active listings have been seen at $536, $570, $606, and $677. One serviced unit sold for $642 on Reverb in September 2026.

The article's own market observation suggests complete, working units with matching power amplifiers may command $800 to $1,500 depending on condition and provenance.

Common issues are well documented. Electrolytic capacitors in the power regulation and signal path often need replacement after 40+ years. Tone, balance, and volume potentiometers can become scratchy or noisy. Cleaning may help, but replacement with modern equivalents or NOS parts is often necessary. Relays used for input selection and tape monitoring can stick or fail. The modular bus connector and internal wiring can suffer from corrosion or fatigue. VU meters may drift or become unresponsive, though specialists can often recalibrate them.

Thevintageknob.org notes that the CA-1000 needs room to breathe. Bias current is high and the unit runs hot. That's not a defect; it comes with Class A operation.

Owner testimony is mixed but leans positive. One owner reports having used theirs since new in 1973, still working perfectly. Another calls the Yamaha Class A amplifiers among the best they've heard. A more critical voice on Audio Asylum finds the preamp section lacking and the Class A power amp section "entry-level audiophile." A Russian forum poster was less charitable still.

Market Value

┌──────────────────────────────────────────────────────────────────────────┐
│ YAMAHA CA-1000                                                  Nov 2026 │
├──────────────────────────────────────────────────────────────────────────┤
│ High      $1,897                                  Latest            $365 │
│ Median    $748                                    Trend                — │
│ Low       $197                                    Volume           ~2/mo │
├──────────────────────────────────────────────────────────────────────────┤
│ $2,000 ┤                                                                 │
│        │                                         .                       │
│        │                                                                 │
│ $1,186 ┤                                              .                  │
│        │                                  .     . .            .      .  │
│        │     .                               .    .   . .                │
│        │.                                                 .         .    │
│   $100 ┤                                                               ..│
│        ├─────────────────────────────────────────────────────────────────│
│    vol │▄    ▄                            ▄  ▄  ▄▄█   █ ▄ ▄    ▄    ▄ ▄▄▄│
│        └─────────────────────────────────────────────────────────────────│
│         2025-12                      2026-04                      2026-08│
└──────────────────────────────────────────────────────────────────────────┘