MASS-Kobo Model 491 | Desktop Headphone Amplifier

Incredible Performance Meets Rare Exclusivity, the MASS-Kobo 491 Stands as a Headphone Amplifier Revered by Audiophiles
- Twin-balanced Monoblock Headphone Amplifier with Four High-performance Amplifier Stages
- Each Unit is Handmade with Individual Components Selected and Personally Tested by One Man, Mr. Masuda
- It Carries the Legacy of the Highly Acclaimed Model 465
- Made to Order in Japan
- Features the Addition of a 4.4mm Balanced Output
Model 491
The MASS-kobo Model 491 is the successor to the flagship Model 465, a twin-balanced monoblock headphone amplifier with four high-performance amplifier stages and fully independent left and right power supplies, a topology more commonly found in high-end loudspeaker amplifiers than in headphone designs. Delivers over 3.5 W + 3.5 W into 32 Ω balanced, enough to drive the HIFIMAN Susvara at reference quality.
Sound Experience
A clean, stress-free presentation that the manufacturer describes as making the listener "forget the amplifier is even there." The independent dual-mono power supplies and twin-balanced topology contribute to a vanishingly low noise floor and exceptional channel separation: the conditions under which low-efficiency planar magnetic headphones reveal their full dynamic and tonal range without the amplifier imposing its own character.
Build
Housed in a compact desktop chassis measuring 13.0 × 9.7 × 4.1" and weighing 13lbs (excluding the power cable), the Model 491 is designed to fit seamlessly into a high-end desktop setup. Its front panel offers a full suite of balanced and single-ended headphone outputs, ensuring compatibility with virtually any modern headphone cable termination.
| Device Features | |
|---|---|
Headphone Amp |
Yes |
Analog Audio Outputs |
XLR 4-pin balanced × 1
XLR 3-pin balanced L/R × 2 4.4mm balanced × 1 1/4-inch TRS × 1 |
Analog Audio Inputs |
XLR 3-pin balanced (electronically balanced) x2
RCA unbalanced × 2 |
Device Weight |
13lbs
|
Dimensions |
13.0 × 9.7 × 4.1"
|
| Amplifier | |
Output Power |
Maximum output (P-P): Unbalanced 22 V P-P; Balanced 32 V P-P (32 Ω, 1 kHz, THD+N 0.05%)
Maximum output (RMS): Unbalanced 7.4 V; Balanced 10.7 V (32 Ω, 1 kHz, THD+N 0.05%) |
