Out of stock - Accepts Pre-Orders
Out of Stock - Allows Pre-Orders
Message us in discord or our website chat to find out pre-order time.
- MASS-Kobo Model 475
MASS-Kobo Model 475
Hand-made Full-Balanced Portable Headphone Amplifier
Balanced output of model 475 is not compatible with unbalanced headphones and earphones.
Unbalanced headphones or earphones connected to the balanced output with or without adapters may cause the amplifier to malfunction.
NEVER connect them to the balanced output. Please use 3.5 mm unbalanced output for unbalanced headphone or earphones
International Customers will incur local taxes and duty charges. Read More.

MASS-Kobo Model 475
The full balanced headphone amplifier model 428, which has gained popularity since its release, now features an upgraded external DC power supply terminal. The previous USB micro B has been replaced with the more advanced USB Type-C, offering improved connectivity.
For enhanced reliability, the input and output terminals for the Balanced connection utilize Pentaconn connectors manufactured by Nippon Dicks Co., Ltd. These connectors are known for their high quality and robustness. Additionally, all internal substrates are directly connected without the use of cables, and the connectors themselves are gold-plated. These design choices contribute to improved sound quality.
These amplifiers are equipped with a convenient mode change-over switch, allowing you to connect both balanced and unbalanced output players. This versatility enables compatibility with a wide range of audio devices.
Both models also feature the output gain-changing switch, which has been well-received in our flagship model 406. With this switch, you can now enjoy listening to all types of headphones and earphones, whether they have dynamic or balanced-armature drivers, using a single amplifier.
When powered by alkaline AA batteries, the amplifier can provide approximately 4 hours of usage time. Please note that the actual battery life may vary depending on the condition and type of batteries used.
Alternatively, you have the option to power the amplifier by connecting a power bank to the USB Type-C terminal. It's important to note that the amplifier does not have a charging function or digital input/output capabilities when powered in this manner.
Technical Specifications
- 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) 0.32 A(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)