This might be of interest to some of you… All FINEMET® transformers are designed and manufactured by Mr. Suzuki, General Industry in Saitama Japan. Their transformers were sold through Noguchi transformer in the past. They also supply well known Japanese audio companies. Mr. Suzuki is also well known field coil speaker designer and leading transformer designer. Winding material and technique is also very important trade secret. He spent several years for refinement.

FINEMET® is Nanocrystalline soft magnetic metal which is special amorphous metal. It's phase characteristics is far better than conventional core material such as Ni and Co-based amorphous metal.

Typically air core inductor is well regarded for speaker filter. However inductor DCR cause phase shift in lower frequency. For ultimate speaker projects, we use Finemet core inductor with over sized core and wire. 

Our Finemet Transformer has very good phase response, in other words VERY transparent. It makes very difficult to use with components with strong personality such as electrolytic capacitors, transformers and chokes with other core materials.

For success with Finemet Transformer, we need to use all Finemet iron with film capacitors that have good phase response. 

Choke input power supply with Finemet Choke is the choice of our power supply topology.


1) Satisfy both high saturation magnetic flux density and high permeability

High saturation magnetic flux density comparable to

Fe-based amorphous metal. High permeability comparable to Co-based amorphous metal.

2) Low core loss

1/5th the core loss of Fe based amorphous metal and

approximately the same core loss as Co-based amorphous metal.

3) Low magnetostriction

Less affected by mechanical stress. Very low audio noise emission.

4) Excellent temperature characteristics and small aging effects

Small permeability variation (less than ±10%) at a temperature range of -50°C~150°C. Unlike Co-based amorphous metals, aging effects are very small.

5) Excellent high frequency characteristics

High permeability and low core loss over wide frequency range, which is equivalent to Co-based amorphous metal.

6) Flexibility to control magnetic properties?B-H curve shape?during annealing

Three types of B-H curve squareness, high, middle and low remanence ratio, corresponding to various applications.

  • FM-NW1: 1.1mH-1.7mH-2.0mH-2.3mH-2.7mH-3.0mH-3.4mH, Max. Input 300W
  • FM-NW2: 2.7mH-3.0mH-3.4mH-3.6mH-3.9mH-4.5mH-5.0mH, Max. Input 300W 
  • FM-NW3: 0.39mH-0.47mH-0.56mH-0.69mH-0.8mH-1.0mH-1.2mH-1.5mH-1.8mH, Max. Input 300W
  • FM-NW4: 3.3mH-3.9mH-4.7mH-5.6mH-6.8mH-8.2mH-10mH, Max. Input 300W
  • FM-NW5: 7mH-9mH-10mH-12mH-15mH-18mH-22mH, Max. Input 300W
  • FM-NW6: 0.14mH-0.16mH-0.18mH-0.21mH-0.25mH-0.3mH-0.34mH-0.39mH-0.47mH, Max. Input 100W