- 1947...2000. Transformer production by Hirata Company, Japan. The brand name was already TANGO by then.
- 2000. With permission of Mr. Hirata, a selected group of people had the opportunity to continue transformer production in their company, using previously Hirata machinery, with a brand licence by Mr. Hirata for the TANGO brand. Actually calling it ISO-TANGO.
- 2014. Production was stopped. Afer this, the TANGO brand was licensed to WAVAC company, and the TANGO machinery became property of Mr. Osawa
- Mr. Osawa started production under ISO-TRANSFORMERS brand, with technical staff of original Hirata company. Machines are now at ISO-TRANSFORMERS. To my opinion this makes ISO-TRANSFORMERS the best successor of the old brand.
Mr. Osawa, is a long time passionate collector of vintage German tube HiFi, such as Klangfilm field coil speakers, Telefunken RGN2004 power unit, RE604 power amp, EMT 997, EMT cartridge, Newmann step up transformers and may more. The company is run with a heart for tube HiFi.
The product line is compact, and excellently focussed on the right kind of tubes which are in use in the HiFi tube scene. Data Sheets show great detail, including frequency curves. Moreover, the ISO transformers have multiple output taps, usually 4,6,8,16 Ohms. Even so, some have in addition to that multiple input taps. This makes the products pleasant and comfortable to use.