The Philips Group consisted of the Philips company in Holland, N. V. Philips Gloeilampenfabrieken, and Mullard (U.K.), Dario (France), Valvo (Germany) among many others. The Amperex and 'Bugle Boy' brands were used mainly in North America. Mullard never acknowledged the parent company in the U.K., presumably in order to remain in the BVA cartel of British manufacturers. The Dario box and the old Mullard one may date from before they were under Philips control. Valves made in many different factories were boxed under the various brands. Many U.K. Mullard valves marked 'Foreign' were made in Philips or Valvo factories. Nearly all Philips group valves have an etched code in the envelope which indicates the place of final manufacture and the valve type and date of manufacture. Sub-assemblies were often sourced from different factories. Some famous audiophile valves, like the Mullard EL34 or ECC83, for instance, are identical, whether made and boxed by Mullard or one of the other factories.
Amperex
Dario
Mullard
Philips
Valvo
