This is a list of European Mullard–Philips vacuum tubes and their American equivalents. Most post-war European thermionic valve (vacuum tube) manufacturers have used the Mullard–Philips tube designation naming scheme. Special quality variants may have the letters "SQ" appended, or the device description letters may be swapped with the numerals (e.g. an E82CC is a special quality version of an ECC82) Note: Typecode explained . The part behind a slash ("/") is the // equivalent.