Yamaha - A-S701 Integrated Amplifier

100 watts a channel at the same honest 0.019% distortion figure as the models below it, plus CD Direct Amplification — a second, source-specific short path that appears here for the first time in the range.

ToP-ART, Yamaha’s Total Purity Audio Reproduction Technology, is a layout philosophy rather than a circuit: the left and right channels are laid out as mirror images and the signal takes the shortest, straightest route from input to output, on the reasoning that a shorter path picks up less noise and adds less distortion. The ART (Anti-Resonance and Tough) Base is the mechanical half of the same idea — a stiffened bottom chassis with a solid centre bar that damps vibration before it reaches the circuit boards. Both are real, named engineering choices; Yamaha publishes no measurement isolating what either contributes.

The A-S701 is the top of Yamaha’s three entry-level A-S models and the first to add a feature rather than just wattage. Alongside Pure Direct it carries CD Direct Amplification, a dedicated shortened path from the CD input to the amplifier stage. Yamaha publishes a separate signal-to-noise figure for it — 104 dB against 99 dB in Pure Direct — but the two are measured under different circuit conditions and should not be read as one number improving on the other for the same input.

Pure Direct routes the signal by the shortest internal path available, bypassing the buffer amplifier and the tone, loudness and balance controls. The continuously variable loudness control does the opposite job when you want it: because hearing loses sensitivity at the frequency extremes as level drops, it dials in a variable amount of bass and treble lift as you turn down, rather than the single fixed curve a simple loudness switch gives you.

Worth knowing when you compare this to the A-S801 above it: the two are rated at exactly the same 100 watts into 8 ohms. The A-S801 is not a more powerful amplifier. What it adds is a USB DAC and a heavier double-bottom chassis. If you have no need to feed the amplifier from a computer, the A-S701 gives you the same output for less money.

Features

• 100 W + 100 W into 8 ohms, 20 Hz – 20 kHz at 0.019% THD
• 120 W + 120 W into 6 ohms at 0.038% THD
• CD Direct Amplification, a second source-specific short signal path unique to this model among the three entry A-S amplifiers
• ToP-ART symmetrical layout with ART Base anti-resonance bottom chassis
• Moving-magnet phono input
• Optical and coaxial digital inputs, PCM up to 192 kHz
• Pure Direct mode and continuously variable loudness control
• Subwoofer output
• Two pairs of gold-plated binding posts with A / B / A+B bi-wiring
• DC OUT for the optional Yamaha YBA-11 Bluetooth adapter
• Available in black or silver

Specifications

• Type: Two-channel integrated amplifier
• Rated power output (8 ohms): 100 W + 100 W, 20 Hz – 20 kHz, 0.019% THD
• Rated power output (6 ohms): 120 W + 120 W, 0.038% THD (owner’s manual)
• Dynamic power (IHF): 140 W into 8 ohms, 170 W into 6 ohms, 220 W into 4 ohms, 290 W into 2 ohms, per channel
• Frequency response: 10 Hz – 100 kHz, ±1.0 dB (Pure Direct); 20 Hz – 20 kHz, 0 ±0.5 dB (CD input)
• Total harmonic distortion: 0.019% or less, CD input to speakers, 20 Hz – 20 kHz at 50 W into 8 ohms
• Signal-to-noise ratio: 99 dB or more (CD, Pure Direct on, IHF-A); 104 dB or more with CD Direct Amplification engaged. These are two different circuit conditions and are not interchangeable
• Damping factor: 240 (US specification page and owner’s manual agree for this model)
• Phono stage: Moving magnet only, 3.0 mV / 47 kilohms
• RIAA deviation: Not published
• Built-in DAC: No. This model has optical and coaxial digital inputs, so a converter is obviously present, but Yamaha names no chip and does not market the amplifier as having a DAC — unlike the A-S801, which is the only integrated in the range with a Yamaha-branded, chip-named USB DAC. There is no USB input and no DSD support here.
• Digital inputs: Optical ×1, coaxial ×1. PCM only, up to 192 / 176.4 / 96 / 88.2 / 48 / 44.1 / 32 kHz
• Analogue inputs: PHONO (MM), CD, LINE 1, LINE 2
• Outputs: Speakers A and B, subwoofer out, REC OUT, DC OUT, headphones
• Preamp out / main in: Not confirmed. The terminal list in Yamaha’s owner’s manual for this model does not show MAIN IN or PRE OUT jacks, and Yamaha does not state their absence either. We report this as a gap rather than guess.
• Balanced XLR input: No
• Headphone output: 470 mV / 470 ohms (CD input, 1 kHz, 200 mV, 8 ohms)
• Tone controls: Bass and treble. Balance control fitted
• Loudness: Continuously variable
• Pure Direct: Yes, plus CD Direct Amplification
• Level meters: No
• Subwoofer output: Yes
• Speaker terminals: Two pairs, gold-plated binding posts, A / B / A+B bi-wiring
• Dimensions (W×H×D): 17-1/8″ × 6″ × 15-1/4″ (435 × 151 × 387 mm)
• Weight: 24.7 lb (11.2 kg)
• Power consumption: 270 W; 0.5 W standby
• Finishes: Black and Silver (A-S701BL and A-S701SL)
• 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: Two years, parts and labour, under Yamaha Corporation of America’s general A/V Products limited warranty, which is the document Yamaha’s warranty index links for this class of product. Yamaha states that warranty registration is not required for coverage. The warranty is enforceable only by the original purchaser and is not transferable. The owner pays shipping to the service centre; Yamaha covers return shipping on a covered repair.