Mahi Monoblock Amplifier (Pair)

The Manley MAHI Monoblock is a compact, all tube power amplifier created for listeners who value clarity, musicality, and precise system matching. Sold as a matched pair, each monoblock powers a single channel, ensuring complete channel separation and a focused, immersive soundstage. Designed to drive high efficiency loudspeakers, the MAHI is hand assembled in California and reflects Manley’s commitment to thoughtful engineering and refined craftsmanship for both home and studio listening environments.

Powered by an EL84 push pull output stage, the MAHI offers switchable Triode and Ultra Linear modes to suit different listening preferences. In Triode mode, it delivers 20 watts with a rich midrange presence and natural dimensionality that complements vocals and acoustic recordings. Ultra Linear mode increases output to 40 watts, providing greater headroom, tighter control, and dynamic authority for more demanding material. A three position negative feedback control allows you to fine tune damping and tonal balance to match your speakers and room.

Premium components such as German WBT binding posts and carefully selected tubes support long term reliability and consistent performance. The result is a pair of monoblock amplifiers that balance warmth, speed, and control in a compact footprint, offering an engaging and customizable listening experience for discerning music lovers.

Features:

Compact Monoblock Design

Dedicated single-channel construction ensures complete channel separation for pure, focused sound in a space-saving form.

Sold as a Matched Pair

Supplied as two monoblocks for true stereo performance with optimal channel separation and balanced sound.

Pure Vacuum Tube Amplification

All-tube circuitry delivers natural warmth, rich tone, and immersive musicality.

Switchable Triode and Ultra-Linear Modes

Choose between a sweeter, more intimate presentation or a more powerful, dynamic sound to match your music and mood.

Adjustable Negative Feedback Control

Fine-tune the amplifier’s character from open and fluid to tight and controlled for ideal speaker matching.

Designed for High-Efficiency Speakers

Optimized to bring out the best in sensitive loudspeakers with lively dynamics and detailed imaging.

EL84 Output Stage

Renowned EL84 tubes provide a smooth midrange, expressive dynamics, and engaging tonal balance.

Enhanced Power Authority

Robust power supply design delivers strong bass control and confident transient response.

Hand-Assembled Craftsmanship

Built in California with carefully selected components for long-term reliability and refined performance.

Premium Build Quality

High-grade connectors and parts ensure secure connections and consistent, high-fidelity sound.

Versatile Home and Studio Use

Ideal for audiophile listening rooms and professional environments seeking clear, dimensional sound.

Specifications:

General Specifications

Device Type: Vacuum Tube Monoblock Power Amplifier

Configuration: Monoblock

Sold As: Matched Pair

Assembly Location: California, USA

Operating Modes: Triode, Ultra-Linear

Output Stage: Push-Pull EL84 Pentode

Recommended Speaker Load: Optimized for 5 Ω

Input Impedance: 110 kΩ

Dynamic Range: 83 dB

Signal-to-Noise Ratio: 82 dB A-weighted (ref. 1W, 20 Hz–20 kHz)

Tubes (Per Monoblock)

Input Tube: 1 × 12AT7EH (Electro-Harmonix, large plate)

Driver Tube: 1 × 12BH7EH or 6414

Output Tubes: 4 × EL84 (ships with NOS EL84M / 6P14P-EB)

Bias & Operating Conditions

Output Tube Quiescent Current: 25 mA

Bias Setting: 250 mVDC across 10 Ω cathode resistor

Gain

FB MIN: 30.7 dB (Triode), 32.1 dB (Ultra-Linear)

FB STD: 28.5 dB (Triode), 29.1 dB (Ultra-Linear)

FB MAX: 26.1 dB (Triode), 27.1 dB (Ultra-Linear)

Negative Feedback

MIN: 3 dB

STD: 6 dB

MAX: 10 dB

Input Sensitivity (Max Output @ 1.5% THD, 1 kHz)

FB MIN: 175 mV (Triode), 155 mV (Ultra-Linear)

FB STD: 312 mV (Triode), 340 mV (Ultra-Linear)

FB MAX: 480 mV (Triode), 566 mV (Ultra-Linear)

Input Sensitivity (1W into 8 Ω): 61 mV, 53 mV

Maximum Output Power (@ 1.5% THD, 1 kHz)

Into 5 Ω — FB MIN: 18W (Triode), 20W (Ultra-Linear)

Into 5 Ω — FB STD: 27W (Triode), 42W (Ultra-Linear)

Into 5 Ω — FB MAX: 28W (Triode), 46W (Ultra-Linear)

Into 8 Ω — FB MIN: 14W (Triode), 24W (Ultra-Linear)

Into 8 Ω — FB STD: 24W (Triode), 40W (Ultra-Linear)

Into 8 Ω — FB MAX: 25W (Triode), 41W (Ultra-Linear)

Distortion

THD+Noise @ 5W: < 0.15%

Frequency Response

Full Power, UL Mode, MAX NFB: 20 Hz – 20 kHz (flat)

5W into 5 Ω: 10 Hz – 30 kHz (flat), –3.75 dB @ 100 kHz

Noise Floor

150 µV (–74 dBu A-weighted)

650 µV (–62 dBu unweighted)

Output Impedance

FB MIN: 1.22 Ω (Triode), 1.35 Ω (Ultra-Linear)

FB STD: 0.80 Ω (Triode), 0.83 Ω (Ultra-Linear)

FB MAX: 0.54 Ω (Triode), 0.54 Ω (Ultra-Linear)

Damping Factor

FB MIN: 4.10 (Triode), 3.70 (Ultra-Linear)

FB STD: 5.45 (Triode), 4.78 (Ultra-Linear)

FB MAX: 9.26 (Triode), 9.26 (Ultra-Linear)

Power Requirements

Idle Power Consumption: 102 W (0.85A @ 120VAC)

Maximum Power Consumption: 168 W (1.4A @ 120VAC)

Operating Mains Voltage: 100V, 120V, or 220–240VAC (factory configured)

Mains Frequency: 50–60 Hz

Fusing

Mains Fuse @ 117VAC: 3A 3AG slow-blow, Littelfuse Series 239

Mains Fuse @ 230VAC: 1.6A 3AG slow-blow, Littelfuse Series 239

B+ Fuse: MDA 400 mA Slo-Blo, ceramic time-delay

Physical Specifications

Dimensions: 11 in (D) × 10 in (W) × 5 in (H)

Shipping Weight: 18 lbs (each)