Instruments Inc. designes and fabricates both switching and linear amplifiers for a variety of demanding applications.

Units they delivered over 40 years ago are still in daily use. Their switching amplifiers are most often built utilizing a PWM system with a carrier frequency of 160kHz. This gives useful output past 20kHz. The S11 series was developed in 1987. They are best for multi-channel systems with a few kVA per channel. The S16 series came along in 2002 as a direct result of their experience with the S11 amplifiers. They are best suited for large systems since each pair of boards delivers 5kVA.