Mahi Monoblocks

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.

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)