Stereo headphone amp meant to fit in a pedal enclosure for use on a pedalboard. Buffers the signal, then splits it to an output meant to go to a mixer and a headphone out. The headphone amp circuit is applied to the signal before the headphone jack. Originally designed to give the ability to run effects after an amp simulator pedal with no effects loop. Example chain: amp sim > wet effects > headphone amp > mixer. References: https://electrosmash.com/images/tech/klon-centaur/klon-centaur-power-supply.png https://aionfx.com/app/files/docs/refractor_documentation.pdf https://www.muzique.com/lab/buffers.htm

The OPAx863 series from Texas Instruments includes the OPA863, OPA2863, and OPA4863, which are low-power, rail-to-rail input/output, voltage-feedback operational amplifiers designed for high-performance applications. These amplifiers feature a unity-gain bandwidth of 110 MHz, a gain-bandwidth product of 50 MHz, and a low quiescent current of 700 µA per channel. The devices operate across a wide supply voltage range of 2.7 V to 12.6 V, making them suitable for both portable and battery-powered systems. With a slew rate of 105 V/µs, 5.9 nV/√Hz input voltage noise, and exceptional harmonic distortion performance (-129 dBc HD2, -138 dBc HD3 at 20 kHz for 2 Vpp output), the OPAx863 is adept for driving SAR and ΔΣ ADCs, acting as ADC reference buffers, low-side current sensing, photodiode TIA interfaces, and other high-precision tasks. Additional features include overload power limiting, output short-circuit protection, and a power-down mode with minimal quiescent current, making the OPAx863 series a versatile and robust choice for applications requiring low power and high-precision analog performance. The series includes single, dual, and quad-channel configurations available in various surface-mount packages to fit different design requirements.

The Texas Instruments OPA863, OPA2863, and OPA4863 are low-power, voltage-feedback operational amplifiers designed to offer a unity-gain stable, rail-to-rail input and output with a 110-MHz bandwidth. These amplifiers are optimized for a broad power supply range from 2.7 V to 12.6 V, catering to a variety of portable and battery-powered applications. Key features include a quiescent current of 700-uA/ch (typical), a gain-bandwidth product of 50 MHZ, input voltage noise of 5.9-nV/VHz, and a slew rate of 105-V/us. The series also highlights specialized versions including the OPAx863A for high precision requirements, and all models integrate features like overload power limit and output short-circuit protection for ruggedized environments. The devices’ applicability spans across multiple domains including low-power SAR and ΔΣ ADC drivers, ADC reference buffers, photodiode transimpedance amplifiers, and more. The comprehensive array of packages available (including SOT-23, VSSOP, WQFN, and TSSOP options) ensures flexibility in hardware design, making these operational amplifiers from Texas Instruments suitable for high-performance, space-conscious, and power-sensitive electronic circuits.

The Texas Instruments OPA835 and OPA2835 are ultra-low-power, rail-to-rail output, negative-rail input, voltage-feedback (VFB) operational amplifiers designed for operation across a wide power supply range of 2.5 V to 5.5 V with a single supply or +1.25 V to +2.75 V with a dual supply. These components are notable for their industry-leading performance-to-power ratio, which features a quiescent current of just 250 µA per channel and a unity gain bandwidth of 56 MHz. They are ideal for battery-powered, portable applications where power efficiency is critical, without compromising on high-frequency performance. The OPAx835 series brings the added benefit of a power-savings mode, reducing current consumption to less than 1.5 µA, making them an attractive choice for high-frequency amplifiers in battery-powered systems. Their compact package options, including SOT-23, SOIC, VSSOP, UQFN, and QFN, cater to space-constrained applications, providing a versatile solution for low-power signal conditioning, audio ADC input buffers, low-power SAR and ΔΣ ADC drivers, portable systems, low-power systems, high-density systems, and ultrasonic flow meters.