Phasemation MA-1500 Power Amplifier

Description

300B Single-Ended Tube Monaural Power Amplifier which can educe the music reality and even the artist’s passion

Phasemation MA-1500 Power Amplifiter

In the world of audio amplifiers, wide kinds of semiconductor amplifiers, tube amplifiers, etc. are released. Therefore, the respective audio features can be enjoyed as a hobby.　Especially the tube power amplifiers has a tube called “fine tube” having a reputation for sound quality and last year we have developed the monaural power amplifier, MA-2000 composed by a parallel single-ended circuit adopting 300B which is the best tube among them and a circuit strongly driven by a transformer-coupled circuit adopting 2A3.”

This year to tell many people the significance of MA-2000, we developed a new monaural power amplifier MA-1500 which has a plentiful 10W output along with an operation due to the transformer-coupled circuit which is single-operating with a 300B single tube.

Phasemation MA-1500 Owner’s Manual

Recieved Awards

Stereo Sound Publishing Stereo Sound Grand Prix 2017 Grand Prix Award
Ongen Publishing Audio Excellence Award 2018 Silver Award
SEIBUNDO SHINKOSHA Publishing MJ Technology of the Year 2017 Tube Amplifier Components Excellence Award
ONGAKU NO TOMO SHA CORP. STEREO magazine Power Amplifier Components
ONGAKU NO TOMO SHA CORP. STEREO magazine Best Buy Components 2019 Main Amplifier Equipment over ¥1,200,000 3rd Place
ONGAKU NO TOMO SHA CORP. STEREO magazine Best Buy Components 2021 Power Amplifier Equipment over ¥1,200,000 2nd Place

Main Features

Toshiba 6CG7 for the Transformer-Coupled Circuit Driving PSVANE 300B Ended-Tube Optimally

Letting the ended-tube PSVANE 300B be the self-bias single pure A-class, the Toshiba 6CG7 as a driver is used on the transformer-coupled circuit. This setup operates the speakers with stability, avoiding wobbling, and is structured to showcase the excellence of 300B’s original quality with the simplest operation.

Composing the Non-Feedback Amplifier by Adopting Triode Tubes in All Stages

We compose the non-feedback amplifier by adopting triode tubes, 5814A+6CG7+300B, in all stages. This design allows for the reproduction of dynamic and very expressive music, achievable only through the non-feedback circuit.

Adopting the Output Transformer and Inter-Stage Transformer Made by LUNDAHL in Sweden

We have adopted inter-stage and output transformers made by LUNDAHL in Sweden, which are well-suited for achieving the desired sound quality. The parallel connection and independent winding structure at the secondary side of the inter-stage transformer ensure reliable transmission of very small signals. Independent terminals that can drive 8 or 4 ohm speakers are provided by utilizing the independent winding structure at the secondary side of the output transformer.

Composed of Two Independent Power Choke Transformers

The power supplies are individually sourced from independent power choke transformers for the driver stage (5814A+6CG7) and the power stage (300B single-ended). This separation eliminates mutual interference between the input signal amplifier circuit and the speaker drive circuit, allowing for clear amplification of signals across a wide range from infinitesimal to high power levels.

Thoroughgoing Design for Decreasing the Noise

We have implemented a comprehensive design to minimize noise, including:

• Rectifier tube 5R4G, which avoids generating switching noise in high voltage power supplies
• Rectifier circuits composed of choke transformers
• 300B heaters directly driven by DC power supplies

MA-1500 Block Diagram