ðə tˈuːb hɐz ɐ tɹˈaɪoʊd fɔːɹ ˌæmplɪfɪkˈeɪʃən, ɐlˈɔŋ wɪð tˈuː dˈaɪoʊdz, wˈʌn tˈɪpɪkli fɔːɹ jˈuːs æz ɐ dɪtˈɛktɚ ænd ðɪ ˈʌðɚɹ æz ɐ ɹˈɛktɪfˌaɪɚ fɔːɹ ˌɔːɾəmˈæɾɪk ɡˈeɪn kəntɹˈoʊl, ɪn wˈʌn ˈɑːnvəlˌoʊp.
The tube has a triode for amplification, along with two diodes, one typically for use as a detector and the other as a rectifier for automatic gain control, in one envelope.