The OA241 is a very low noise discrete operational amplifier tailored for microphone preamplifiers and mid-stage gain blocks. This proprietary design is the heart of Ingram Engineering mic pre-amps and is now being made available as a module.
The OA241 has a musical sound that gradually transitions from lightly colored, semi-transparent, to compression dominated by 2nd order distortion as it is pushed hard. Rather than use an abrupt “hockey-stick” transition into high levels of distortion like other discrete op amps and integrated amps, the OA241 is designed to have a gradual increase in primarily 2nd order distortion starting 20 dB below clipping up to the onset of hard clipping. This allows it to add color to taste when pushed towards the upper end of the dynamic range.
The design uses a FET input stage and a heat spreading output stage topology that realizes excellent thermal performance. The potted module contains an integrated heat sink for further heat reduction and longest life. Both input and output are protected against surges, power supply pins have internal RF filtering, and the amplifier is internally compensated for good stability.
The OA241 is an audio building block that combines excellent technical performance with the ability to impart character on music. It is available in the industry standard 6-pin discrete op amp footprint utilized in classic and modern audio equipment. Whether the OA241 is used as a better sounding substitute for gear that uses the modular op amp footprint or is used as a basis for new designs, it is an excellent choice that provides numerous advantages.