24V Attenuator, Buffer,Speaker Expander for Self Amp. Spkrs "The BUFEX is a continuously variable speaker attenuator that can remotely control the volume of a network of speakers.The BUFEX also provides output buffering for up to 150 self-amplified speaker inputs and allows speaker system expansion of existing 100V, 70V, or 25V central amplifier systems.The BUFEX includes a bypass function that can override the volume control knob setting when activated by a contact closure or open collector output. This allows emergency announcements to be heard through all speakers in a system even if the volume control knob setting is set low or off.A PCB-mounted bypass trim control adjusts the volume when in bypass mode with a maximum of 12 dB of attenuation.The BUFEX fits into a single gang electrical box. - Continuously variable attenuator - Drive up to 150 self-amplified speaker inputs - 100V, 70V, 25V, and page port level selectable input - Bypass trim control for emergency paging (12 dB of preset control over level of bypass announcements) - Mounts in a single gang electrical box - Rugged and attractive stainless steel plate with engraved lettering - Easy and secure terminal strip connections - Two-Year Warranty"