MASS-Kobo is the legendary Headphone Amplifier manufacturer in Shizuoka, Japan, designed and made by the recording engineer and electrical engineer Mr. Masuda. Mr. Masuda, with his MASS-Kobo, has been in the high-end industry since 2007. Today we have brought the most recent product in the portable lineup—Model 475 and the high-efficiency desktop amplifier Model 433.
Model 475 is the newest successor of model 428 with the updated external DC power supply terminal from Micro USB to USB Type C. The balanced input and output terminal uses Pentaconn, manufactured by Nippon Dicks Co., Ltd., with high reliability. No cable between the internal substrates is used, and all the connectors are gold-plated. The sound quality is clearly improved.
Model 475 amplifier is equipped with a mode change-over switch that enables you to connect both balanced and unbalanced output players. Model 475 shares the same output gain-changing switch as the one used in Model 406, the previous flagship desktop amplifier of MASS-Kobo.
Now you can listen to all types of earphones with dynamic and balanced-armature drivers properly with a single amplifier.
It can be used for about 4 hours with alkaline AA batteries.
It can also be powered by connecting a power bank to the USB Type-C terminal.
Specifications:
Model: Full-Balanced Portable Stereo headphone amplifier
Input: φ4.4 TRRS x 1 (balanced or unbalanced)
Output: 4.4 TRRS (balanced), φ3.5 TRS (unbalanced)
Maximum Input Level: +16dBm (balanced), +10dBm (unbalanced)
Maximum Output Level
(P-P): 7 V (balanced), 3.5V (unbalanced) (with 32Ω loaded, 1kHz, THD+N 0.5%)
(RMS): 2.3V (balanced), 1.2 V (unbalanced) (with 32Ω loaded, 1kHz, THD+N 0.5%)
Frequency Characteristics: 20Hz - 20kHz (-1dB)
Noise Level: Less than 40μV (in the minimum volume position, 32Ω loaded) Less than 150μV (in the maximum volume position, 32Ω loaded)
Power Supply: AA Alkaline or rechargeable battery x 4
External Power Supply: Micro USB +5v
Consumption Current:
0.19A (battery 6V, No signal) 0.21A (rechargeable battery, 4.8V No signal) 0.21A (USB 5V, No signal)
0.28A (battery 6V, 1/8 Output) 0.32A (rechargeable battery, 4.8V, 1/8 output) 0.31A(USB 5V, 1/8 Output)
0.49A (battery 6V, Maximum Output) 0.61A (rechargeable battery), 4.8V, Maximum Output) 0.58A (USB 5V, Maximum Output)
Size: 97mmW x 132mmD x 40mmH (not include protrusions)
Weight: 440g (with batteries), 382g (without batteries)
Model 475 is in stock at MusicTeck: https://shop.musicteck.com/products/mass-kobo-model-475-full-balanced-portable-headphone-amp
Model 433 fully balanced amplifier successes the sound signature from the previous flagship Model 406 and the most popular Model 394II. Model 433 is specially designed for full-size dynamic headphones. The maximum distortion-free output reaches 1.2W per channel, which is adequate for dynamic headphones like Focal Utopia, Clear MG, Sennheiser HD800s, etc. You can enjoy the unique MASS-Kobo tuning with the ultimate transparency, speed, and dynamic starts with Model 433.
Model 433 has a set of inputs that can be used either with XLR Balance Input or RCA Unbalance Input (Unbalance Input converted to Balance signal by the inside amp.).
The power supply is AC 100V-240V, 50/60Hz for worldwide use.
Specifications：
Model: Full Balanced Stereo headphone amp
Input: Electronically Balanced = XLR3-31, Unbalance = RCA
Output: Balance = XLR4-31, Unbalance = φ6.3 TRS
Input Impedance: 3.7kΩ (XLR)/ 12kΩ (RCA)
Reference Input Level: +4dBm or -10dBm (XLR)/ -10dBm (RCA)
Maximum Input Level: +25dBm (XLR)/ +10dBm (RCA)
Maximum Output Level
(P-P): Balance = 18.8V (with 32Ω loaded, 1kHz, THD+N 0.05%) Unbalance = 12.2V (with 32Ω loaded, 1kHz, THD+N 0.05%)
(RMS): Balance = 6.2V (with 32Ω loaded, 1kHz, THD+N 0.05%) Unbalance = 4.1V (with 32Ω loaded, 1kHz, THD+N 0.05%)
Maximum Output without Distortion: Balance = 1.2W+1.2W, Unbalance = 500mW +500mW(with 32 ohm load, 1kHz, THD+N 0.05%)
Frequency Characteristics: 10Hz - 100kHz (-0.5dB)
Power Supply: AC100 - 240V, 50/60Hz
Electric Energy Consumption: 0.5A (with AC100V)
Size:232mmW x 210mmD x 48mmH (except the rubber feet and projections)
232mmW x 240mmD x 51mmH (including the rubber feet and projections)
Weight: 2.4kg (without the power cable)
Model 433 is in stock at MusicTeck: https://shop.musicteck.com/products/mass-kobo-model433-full-balanced-headphone-amp
Model 475 is the newest successor of model 428 with the updated external DC power supply terminal from Micro USB to USB Type C. The balanced input and output terminal uses Pentaconn, manufactured by Nippon Dicks Co., Ltd., with high reliability. No cable between the internal substrates is used, and all the connectors are gold-plated. The sound quality is clearly improved.
Model 475 amplifier is equipped with a mode change-over switch that enables you to connect both balanced and unbalanced output players. Model 475 shares the same output gain-changing switch as the one used in Model 406, the previous flagship desktop amplifier of MASS-Kobo.
Now you can listen to all types of earphones with dynamic and balanced-armature drivers properly with a single amplifier.
It can be used for about 4 hours with alkaline AA batteries.
It can also be powered by connecting a power bank to the USB Type-C terminal.
Specifications:
Model: Full-Balanced Portable Stereo headphone amplifier
Input: φ4.4 TRRS x 1 (balanced or unbalanced)
Output: 4.4 TRRS (balanced), φ3.5 TRS (unbalanced)
Maximum Input Level: +16dBm (balanced), +10dBm (unbalanced)
Maximum Output Level
(P-P): 7 V (balanced), 3.5V (unbalanced) (with 32Ω loaded, 1kHz, THD+N 0.5%)
(RMS): 2.3V (balanced), 1.2 V (unbalanced) (with 32Ω loaded, 1kHz, THD+N 0.5%)
Frequency Characteristics: 20Hz - 20kHz (-1dB)
Noise Level: Less than 40μV (in the minimum volume position, 32Ω loaded) Less than 150μV (in the maximum volume position, 32Ω loaded)
Power Supply: AA Alkaline or rechargeable battery x 4
External Power Supply: Micro USB +5v
Consumption Current:
0.19A (battery 6V, No signal) 0.21A (rechargeable battery, 4.8V No signal) 0.21A (USB 5V, No signal)
0.28A (battery 6V, 1/8 Output) 0.32A (rechargeable battery, 4.8V, 1/8 output) 0.31A(USB 5V, 1/8 Output)
0.49A (battery 6V, Maximum Output) 0.61A (rechargeable battery), 4.8V, Maximum Output) 0.58A (USB 5V, Maximum Output)
Size: 97mmW x 132mmD x 40mmH (not include protrusions)
Weight: 440g (with batteries), 382g (without batteries)
Model 475 is in stock at MusicTeck: https://shop.musicteck.com/products/mass-kobo-model-475-full-balanced-portable-headphone-amp
Model 433 fully balanced amplifier successes the sound signature from the previous flagship Model 406 and the most popular Model 394II. Model 433 is specially designed for full-size dynamic headphones. The maximum distortion-free output reaches 1.2W per channel, which is adequate for dynamic headphones like Focal Utopia, Clear MG, Sennheiser HD800s, etc. You can enjoy the unique MASS-Kobo tuning with the ultimate transparency, speed, and dynamic starts with Model 433.
Model 433 has a set of inputs that can be used either with XLR Balance Input or RCA Unbalance Input (Unbalance Input converted to Balance signal by the inside amp.).
The power supply is AC 100V-240V, 50/60Hz for worldwide use.
Specifications：
Model: Full Balanced Stereo headphone amp
Input: Electronically Balanced = XLR3-31, Unbalance = RCA
Output: Balance = XLR4-31, Unbalance = φ6.3 TRS
Input Impedance: 3.7kΩ (XLR)/ 12kΩ (RCA)
Reference Input Level: +4dBm or -10dBm (XLR)/ -10dBm (RCA)
Maximum Input Level: +25dBm (XLR)/ +10dBm (RCA)
Maximum Output Level
(P-P): Balance = 18.8V (with 32Ω loaded, 1kHz, THD+N 0.05%) Unbalance = 12.2V (with 32Ω loaded, 1kHz, THD+N 0.05%)
(RMS): Balance = 6.2V (with 32Ω loaded, 1kHz, THD+N 0.05%) Unbalance = 4.1V (with 32Ω loaded, 1kHz, THD+N 0.05%)
Maximum Output without Distortion: Balance = 1.2W+1.2W, Unbalance = 500mW +500mW(with 32 ohm load, 1kHz, THD+N 0.05%)
Frequency Characteristics: 10Hz - 100kHz (-0.5dB)
Power Supply: AC100 - 240V, 50/60Hz
Electric Energy Consumption: 0.5A (with AC100V)
Size:232mmW x 210mmD x 48mmH (except the rubber feet and projections)
232mmW x 240mmD x 51mmH (including the rubber feet and projections)
Weight: 2.4kg (without the power cable)
Model 433 is in stock at MusicTeck: https://shop.musicteck.com/products/mass-kobo-model433-full-balanced-headphone-amp
