A Pair of

New Interstage Driver Transformers

A-107 (7K Ohms, 25-25,000Hz +-2dB)

from Hashimoto Electric Co., Ltd.

Tokyo, Japan

Possibly One of the Best Sounding Interstage Driver Transformers

Ever Built

As Good as Tamura or Tango, or Better

With 21st Technologies

 Based on 60 years of Sansui Experiences

Introducing the Hashimoto A-107:

The Hashimoto A-107 is a very versatile interstage driver transformer with the possibility of using both the primary and the secondary for series or parallel connection.  The primary impedance of the A-107 (with the primary series connection) is 7K Ohms that is suitable for a triode driver stage with the maximum of 10 mA primary current (20 mA with the primary parallel connection).  The secondary of the A107 can be used for series, parallel, or Push-Pull connection with 1:2, 1:1, or 1:1+1 primary to secondary ratio, respectably.  When the secondary is connected as the Push-Pull arrangement, the A-107 can be used as a phase splitter.  Because of its wide frequency response range (25 to 25,000 Hz +-2dB - please click the right thumbnail to see the actual chart), the A-107 virtually eliminates the weakness of interstage driver transformers with the incredible mid range sound that you can not simply experience through CR couplings.

The A-107 measures 52 (W) x 58 (D) x 85 (H) mm, and weighs 0.8Kg (1.8 LB).  The Primary Inductance is 70H (under the primary series connection, Ib=5mA, 5V, 50Hz).

The Hashimoto A-107 is one of two interstage driver transformers that Hashimoto Electric, Ltd. in Tokyo Japan introduced in 2002.  Today, Hashimoto products are regarded as one of the premier tube amp transformers among Japanese hi-fi enthusiasts and columnists who originally introduced the sound of single-ended amplifiers in the world during1980’s and 1990’s.  In fact, some of most influential columnists have been switching their favorite transformers of their choice from Tamura or Tango, to ones with Hashimoto brand, such as the A-105.

Who is Hashimoto Electric anyway?  Hashimoto is by-no-means a new comer in this very traditional, but exciting industry.  Hashimoto Electric, Ltd., in Tokyo Japan has been a long-time Sansui transformer OEM (since 1960’s).  Hashimoto merged Sansui’s transformer business in 1978, and Hashimoto was the company who reproduced the AU-111 transformers when Sansui reissued the famed AU-111 in 1999 as the AU-111 Vintage.  As a matter of fact, Hashimoto is the only company that still carries the original Sansui logo on its product lines, and some of Hashimoto’s key engineers are ex-Sansui engineers. 

Today, Hashimoto Electric produces not only various traditional transformers that Sansui pioneered many years ago, but also high-end tube amp transformers under its own brand name.  The amazing thing is that all Hashimoto transformers are still handcrafted one-by-one by very skilled and experienced employees (Please refer to the actual photos I took when visited Hashimoto last June).

Because some of Hashimoto engineers have more than 40 years of transformer designing experiences through out Sansui and Hashimoto era, all Hashimoto transformers still maintain the superior characteristics and sound of Sansui transformers.  In addition, all Hashimoto transformers are redesigned from the ground up.  This means that Hashimoto transformers are the 21st Century products that have been fine-tuned with computer aided programs and have utilized new materials that were simply not available forty some years ago.  As the result, the A-107 is one of the leading Hashimoto products that have been winning reputations among critics as, "The sound through Hashimoto transformers simply belongs to a different class compared with that of competitions."

Should you need a pair of interstage driver transformer with 5K Ohms primary - the A-105.  Please let us know.  We will import them, and list them on eBay for you.