Model 252AP Discrete Operational Amplifier

Updated May 3rd, 2023

Model 252AP Datasheet and Specifications PDF
Model 252AP, 990Enh-Ticha, 995FET-Ticha Mechanical Options Application Note AN-18
Model 252AP Purchase Online

General Description:
Model 252AP Discrete Operational Amplifier

The Sonic Imagery Labs Model 252AP is a high performance discrete operational amplifier designed for professional audio applications and areas where ultralow noise and low distortion is required. The 252AP is best suited for use in circuits with medium to high source impedances and with microphone input transformers with high turns ratios (> 1:4).

The Model 252AP is a modern re-engineering of the classic 2520 discrete op-amp. It was designed as an enhanced higher performance upgrade replacement with a focus on superior AC and DC performance. The pinouts conform to the 2520/990 package, allowing direct replacement.

The all-discrete SMT design is similar to the API2520 basic topology but has been redesigned to use an ultra-precision differential super-matched input transistor pair specifically designed to meet the requirements of ultra-low noise and ultra-low THD audio systems. A variant (252AP-ULN) is also available for ultra damn low noise applications. (0.560nV/rtHz at 1kHz) Unlike the original API2520 design, the 252AP can incorporate two precision matched pair transistors as the differential input stage. A total of 4 matched devices, for ultra-ultra low noise applications. These devices are selected by the manufacturer at final test to Sonic Imagery Labs noise, Vos, Ic and Vbe matching specifications.

DC perfomance is easily a magnitude better than previous counterparts. With an offset voltage of better than ±35uV (at Av1) and input leakage better than <30nA, the Sonic Imagery Labs Model 252AP is well suited for DC coupled audio applications in which output offset errors cannot be tolerated.

In addition to the enhanced input stage, and unlike the original API2520 devices, the Sonic Imagery Labs 252AP uses precision temperature stable power supply independent current sources. Supply independent current sources allow the bias of the input and matched pair differential VAS stage to remain locked at the optimum operating point regardless of power supply voltage.

Another feature not found in the original API2520 design is the addition of matched pair active current loads which gives the Model 252AP differential input and VAS stage it’s outstanding (PSRR) power supply noise rejection ratio performance.

The Sonic Imagery Labs 252AP can be operated from ±10V to ±25V power supplies. The redesigned input stage circuitry provides outstanding common-mode rejection and maintains low input bias current over its wide input voltage range, minimizing distortion. The 252AP is unity-gain stable and provides outstanding dynamic behavior over a wide range of load conditions.

Integrated power transistor heatsinks coupled to a anodized aluminum enclosure keeps the Sonic Imagery Labs 252AP operating within a wide safe operating area (SOA) and does not suffer from Beta droop when driving heavy loads. Each amplifier is individually fully tested and meets or exceeds published specifications.


• Ultra Low Total Harmonic Distortion, 0.0003 THD+N @ 1kHz
• Ultra Low Noise 0.89nV/rtHz typical@1Khz Rs=150 ohm
• High Current Output Drive (250mA peak)
• +28dBu Output Levels (into 600 ohms)
• Standard Gain Block Footprint
• Operates over ±10V to ±28V supply rails
• Much lower output offset voltage than existing counterparts
• Lower input leakage current than existing counterparts
• Particular emphasis on audio performance
• Designed, assembled and produced in the USA
• 3 Year Warranty


• Low Impedance Line Amplifiers and Drivers
• Active Filters and Equalizers
• Summing/Mixer Amplifiers
• High Performance Microphone Preamplifiers
• High Performance A/D and D/A front end Preamplifier
• High Performance D/A I-V convertors
• High Current Buffer Amplifier


Model 252AP Datasheet and Specifications PDF
Model 252AP, 990Enh-Ticha, 995FET-Ticha Mechanical Options Application Note AN-18
Model 252AP Purchase Online

See Also

Sonic Imagery Labs Model 992Enh-Ticha- Discrete Op Amp DIP8
Sonic Imagery Labs Model 994Enh-Ticha- Dual Discrete Op Amp DIP8
Sonic Imagery Labs Model 995FET-Ticha- FET Discrete Op Amp 990/2520
Sonic Imagery Labs Model 990Enh-Ticha- Discrete Op Amp 990/2520

Contact us directly for OEM and quantity pricing.

All specifications subject to change without notice. The information provided herein is believed to be reliable; however; Sonic Imagery Labs assumes no responsibility for inaccuracies or omissions. Sonic Imagery Labs does not warrant or authorize any Sonic Imagery Labs products for use in life support devices and/ or systems.

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