Philips SM30 legacy public address system
Philips SQ40 and SQ45 high performance public address amplifiers
  The SQ45 range of public address, high performance, audio power amplifiers, has been designed to fulfil the most professional public address requirements. Due to their architectural design and high degree of versatility, they complement any tailored PA system; making them ideal for multi-zone projects requiring amplification for a variety of audio signals simultaneously. SQ40 amplifiers preceded the SQ45 range.

- PA power amplifiers for table top or 19" rack mounting
- Balanced audio inputs with preset sensitivity controls
- Matching transformer for loudspeakers with
..100V, 70V and 50V tappings
- Emergency external battery supply with remote switching
- Built in monitoring facility with VU meter and headphones
SQ45 amplifiers were available in the following configurations:
LBB 1342/40 - 1 x 100 Watt
LBB 1343/40 - 2 x 100 Watt
LBB 1344/40 - 1 x 200 Watt
LBB 1346/40 - 4 x 100 Watt
LBB 1347/40 - 2 x 200 Watt
LBB 1348/40 - 1 x 400 Watt

While the Philips SQ40 and SQ45 amplifiers are no longer manufactured we do offer simple and cost effective Bosch solutions for users wishing to replace faulty items or upgrade their system, see upgrading your SM30.

You can contact us directly or if you know which SQ40 or SQ45 part you need to replace please complete our quotation request form and a member of our technical team will respond immediately.
Philips SQ45 LBB 134X/XX power amplifier- datasheet
Philips SQ45 LBB 134X/XX power amplifier- user manual

The role of the SQ45 within an SM30 public address system
Within the Philips SM30 public address system, the SQ40/45 power amplifiers feed the loudspeakers located in geographical and/or functional zones where people must be reached with background music, announcements, pre-recorded messages and alarm signals.

The SQ40/45 'music' input with adjustable pre-set volume control was ideally suited for distributing one out of several continuous background music sources.The 'priority call' input with a fixed input level is used for occasional paging and other calls. An in-built relay switches the amplifier from the 'music' input to the 'priority call' input. Such functions are controlled by the Philips SM30 Control Centre (see parts list).

An additional feature included in all SQ45 range of amplifiers is a balanced 'Test Input' facility, used for injecting a 20kHz 'pilot-tone' to monitor the amplifiers performance. If used in combination with the SM40 microprocessor controlled surveillance system (see parts list) all amplifiers, loudspeaker cabling and speakers will be constantly monitored.

For more information or assistance in replacing or upgrading your SQ40 or SQ45 amplifiers please do not hesitate to contact us. For more detailed information about our services or how to purchase products please see How to Buy.
1 Faraday Road, Peterlee, Co Durham, SR8 5AP. Registered in England no. 3451873