Where can I find suitable replacement tubes for ELA amplifiers and classic public address systems?

For classic ELA amplifiers and older public address systems, the exact tubes that are really required for operating the unit are often decisive. This applies, for example, to equipment from Siemens, Telefunken, Dynacord, Electro-Voice, Telewatt / Klein + Hummel and similar amplifiers from that period. Typical tubes in this field include EL500, EL504, EL12, EL34, ECC83 and, in the case of Klein + Hummel, also EL5000. For Siemens, for example, the 6S Ela 2524 with EL34 and ECC83 is documented; in many ELA, studio and public address amplifiers from these years, exactly these types appear again and again. Anyone who wants to preserve such equipment or make it operational again will find the desired tube, also premium matched on request, at BTB.