Yamaha - M-5000 Power Amplifier

The flagship power amplifier of Yamaha’s 5000 Series: a floating balanced design delivering 100 watts a channel into 8 ohms and 200 into 4, bridgeable to 400 watts mono, with analogue VU meters and a damping factor of 300 or better.

Yamaha calls this a Floating Balance Amplifier, and the term is literal — the entire power amplifier circuit floats electrically relative to chassis ground, with the power supply rails connecting symmetrically to the output stage. Separate input stages handle the balanced and unbalanced inputs. The amplifier is built as two identical blocks, one per channel, and a front-panel MODE selector switches between stereo and monaural operation; a bridged mono pair requires two M-5000 units, one per channel.

The Mechanical Ground Concept handles vibration separately from the electrical floating. The transformer, block capacitors and heat sink are bolted rigidly and directly to the frame rather than isolated from it, giving the heavy components a stiff mechanical path to ground. The toroidal transformer sits on a 3 mm pure brass base and feeds four separate circuits. Construction is left-right symmetrical throughout and the amplifier stands on brass spiked feet that rotate for levelling.

The front panel carries analogue meters to the 2.5 accuracy class, switchable between off, peak (instantaneous level) and VU (perceived level), with an adjustable dimmer. Read the power figures with their conditions attached: the rated 100 watts into 8 ohms is a full-bandwidth continuous figure at 0.07% distortion, while the 125-watt IEC figure is taken at a single 1 kHz tone at a tighter 0.02%, and the 135-watt JEITA figure at 10% distortion. Different standards, not different amplifiers.

Features

• Full floating and balanced transmission from input to output
• 100 W + 100 W into 8 ohms and 200 W + 200 W into 4 ohms, 20 Hz – 20 kHz at 0.07% THD
• 400 W into 8 ohms in monaural mode; stereo / mono MODE selector on the front panel
• Damping factor of 300 or better into 8 ohms at 1 kHz
• Signal-to-noise ratio of 110 dB (IHF-A)
• Mechanical Ground Concept: transformer, capacitors and heat sink bolted directly to the frame
• Toroidal transformer on a 3 mm pure brass base feeding four separate circuits
• Analogue meters to the 2.5 accuracy class, switchable off / peak / VU with dimmer
• One balanced XLR and one RCA input per channel
• Brass spiked feet, rotatable for levelling
• Five-year US parts and labour warranty

Specifications

• Type: Two-channel power amplifier, bridgeable to monaural
• Rated output power: 100 W + 100 W into 8 ohms and 200 W + 200 W into 4 ohms, both 20 Hz – 20 kHz at 0.07% THD, two channels driven; 400 W into 8 ohms driven monaurally
• Maximum output power: 220 W + 220 W into 4 ohms (1 kHz, 0.7% THD)
• IEC output power: 125 W + 125 W into 8 ohms (1 kHz, 0.02% THD). Note this single-frequency figure exceeds the full-bandwidth rated figure because it is measured to a different standard; the two are not interchangeable
• Maximum effective output power (JEITA): 135 W + 135 W into 8 ohms, 270 W + 270 W into 4 ohms, both at 1 kHz and 10% THD
• Dynamic power (IHF): 125 W into 8 ohms, 170 W into 6 ohms, 250 W into 4 ohms, 500 W into 2 ohms, per channel
• Dynamic headroom: 0.97 dB into 8 ohms
• Power bandwidth: 10 Hz – 50 kHz (8 ohms, 0.1% THD, 45 W)
• Damping factor: 300 or higher (8 ohms, 1 kHz)
• Frequency response: 5 Hz – 100 kHz, +0 / −3 dB; 20 Hz – 20 kHz, +0 / −0.3 dB
• Total harmonic distortion plus noise: 0.035% stereo (balanced line to speaker out, 20 Hz – 20 kHz, 50 W into 8 ohms); 0.05% monaural (200 W into 8 ohms)
• Signal-to-noise ratio: 110 dB (IHF-A network)
• Residual noise: Balanced 40 µVrms; line 50 µVrms
• Channel separation: 90 dB or better at 1 kHz; 70 dB or better at 10 kHz
• Input sensitivity and impedance: Balanced 2.0 Vrms / 47 kilohms; line (RCA) 1.0 Vrms / 47 kilohms
• Maximum input voltage: Balanced 2.20 Vrms; line 1.10 Vrms (both 1 kHz, 0.5% THD)
• Inputs: RCA ×1, balanced XLR ×1, trigger in ×1
• Outputs: Speaker binding posts, trigger out ×1. No line-level output; Yamaha publishes no output impedance figure for this amplifier
• Level meters: Analogue, 2.5 accuracy class. Switchable off / peak / VU with adjustable dimmer
• Bridging: Yes, via the MODE selector. A bridged stereo pair requires two M-5000 units
• Chassis: Mechanical Ground Concept — transformer, block capacitors and heat sink fixed directly to the rigid frame; left-right symmetrical construction
• Transformer: Toroidal, on a 3 mm pure brass base, feeding four separate circuits
• Internal wiring: Thick wire with screw-type connections. Yamaha names no copper purity grade for this model
• Feet: Brass spikes, rotatable for levelling
• Finishes: Mirror-finish side panels. Yamaha does not itemise further finish options on the specification page
• Dimensions (W×H×D): 17-1/8″ × 7-1/8″ × 18-1/4″ (435 × 180 × 464 mm)
• Weight: 59.3 lb (26.9 kg)
• Power consumption: 400 W; 800 W maximum. Standby 0.2 W, off 0.1 W
• Country of manufacture: Not published. Yamaha prints no country-of-manufacture statement on this model’s US product pages, specification tables or owner’s manual. The only geographic reference in Yamaha’s own documentation is the corporate head-office address in Hamamatsu, Japan, which is a company address and not a manufacturing statement. Third-party retailers and reviewers often assert “made in Japan” for this model — Yamaha does not.
• Warranty: Five years, parts and labour. This model is named individually in Yamaha’s Limited Warranty on Premium Hi-Fi Products, which supersedes the general two-year A/V Products term that covers the rest of the range. Registration is not mentioned in the document and coverage is not conditioned on it. Cover is limited to the original owner and is not transferable.