Simms-Watts PA100 100W 4 Channels Head

Simms-Watts was a short-lived but influential British amp maker started by west London music retailer Dave Simms and electronics designer Richard “Rick” Watts. The company built a range of high quality instrument and PA amplifiers around the turn of the 1970s, and its early success was significant enough that EMI later bought the business.

The company’s amp design philosophy is similar to that off contemporary Hiwatt ampos, and they use some of the same components, including the highly desriable Partridge transformers. The P.A. 100 (PA100) is one of Simms-Watts’ valve public address heads: a 100-watt, four-channel design built around a quartet of EL34 power valves. Each channel has its own Bass, Treble and Volume controls plus two Hi-Z inputs, so you can run multiple sources and balance them from the front panel. A global Master Volume and Presence control sit after the channel section, along with separate Standby and Mains switches.

Although it was sold as a PA head, the PA100 is frequently used as a guitar or bass amp because it offers a lot of clean volume and takes pedals well. Simms-Watts amps also had high-profile users, including The Who’s John Entwistle and David Bowie Sprider From Mars era guitarist Mick Ronson. In later years, players such as Jamie Cook of Arctic Monkeys have kept the Simms-Watts name in circulation, mainly through the AP-series heads.

This particular 1970s PA100 shows plenty of cosmetic wear from decades of gigs, with scuffs and chips to the covering and faceplate edges. It is in fully working condition. Unlike many guitar heads that focus on preamp gain, the PA100 is essentially a four-channel mixer feeding a large valve power section, so most drive comes from pushing the power amp.

SPECIFICATIONS

• Manufacturer: Simms-Watts
• Model: P.A. 100 (PA100)
• Type: All-valve public address amplifier head, commonly used as an instrument head
• Power output: 100W
• Channels: 4
• Channel controls: Bass, Treble, Volume (per channel)
• Master controls: Master Volume, Presence
• Inputs: 8 x 1/4″ Hi-Z inputs (2 per channel)
• Power valves: 4 x EL34
• Preamp/driver valves: ECC83/12AX7 type, commonly 4 x ECC83 in PA100 examples
• Switching: Standby switch, Mains on/off switch
• Indicator: Front panel pilot lamp
• Speaker output: 1 x 1/4″ output jack
• Output impedance selector: 7.5Ω / 15Ω
• Mains input: IEC-style inlet
• Mains voltage: 220V
• Cabinet: Tolex-covered wooden head shell with top carry handle