SONIC IMAGERY LABS 252AP Discrete OPA

Sonic Imagery Labs' model 252AP is a high-performance, discrete operational amplifier (OPA) designed for professional audio applications and areas where ultra-low noise and low distortion are required. The 252AP is particularly well suited to circuits with medium to high source impedance, and to microphone input transformers with high transformation ratios (> 1:4).

The 252AP is a modern re-engineering of the classic 2520 discrete OPA.It has been designed as an improved, higher-performance replacement model, with particular attention to superior AC and DC performance. Pin-outs conform to the 2520/990 package, allowing direct replacement.

The fully discrete SMT design is similar to the basic API2520 topology, but has been redesigned to use two pairs of ultra-precise, perfectly matched differential input transistors, specially designed to meet the requirements of ultra-low noise, ultra-low THD audio systems. These transistors are specifically selected by Sonic Imagery Labs to meet the brand's noise, Vos, Ic and Vbe specifications.

DC performance is far superior to that of analog models. With an offset voltage better than ±35uV (at Av1) and an input leakage of less than <30nA, the 252AP is ideally suited to DC-coupled audio applications where output offset errors cannot be tolerated.

In addition to the improved input stage, and unlike the original API2520 OPAs, the Sonic Imagery Labs 252AP uses accurate, temperature-stable, supply-independent current sources. Power supply-independent current sources enable the input bias and matched-pair differential VAS stage to remain locked at the optimum operating point, regardless of the supply voltage.

Another feature not found in the original API2520 model is the addition of matched pairs of active current loads that give the 252AP's differential input and VAS stage its outstanding power supply noise rejection ratio (PSRR) performance.

The Sonic Imagery Labs 252AP can operate with power supplies from ±10V to ±25V. The redesigned input stage circuit offers exceptional common-mode rejection and maintains a low input bias current over its wide input voltage range, minimizing distortion. The 252AP is sandable to unity gain and offers exceptional dynamic behavior over a wide range of load conditions.

Integrated heat sinks for the power transistors, combined with an anodized aluminum case, allow the Sonic Imagery Labs 252AP to operate within a wide safe area (SOA) and not suffer from Beta drop when using heavy loads. Each amplifier is fully individually tested and meets or exceeds published specifications.