API 535-LA 500 Series Line Amplifier
Best professional tool for adding analog character to audio.
The API 535-LA line amplifier is a versatile 500 Series module designed to amplify and attenuate input and output signals, offering significant flexibility and classic API sound. It's ideal for adjusting levels on keyboards, mic pres, or processors lacking dedicated controls, and can also add warmth to digital signals. Built with API's renowned engineering, it features discrete 2510 and 2520 op amps and proprietary transformers, ensuring superior sonics and build quality for driving long balanced cable runs with minimal distortion.
$595.00
Owner Satisfaction
4.7
/ 5
Category Rank
421
/ 1719
#421 in Power Amplifiers
Price vs Category Average
-93%
Below average
Output gain range
645
/ dB to dB
Who it's for
- Audio engineers seeking classic analog warmth and punch for their mixes
- Studio professionals needing to maintain signal quality across complex setups
- Producers and engineers expanding their modular 500 Series processing capabilities
Who should skip it
- Budget-conscious home studio owners or those starting their gear collection
- Users expecting versatile processing from a single 500 Series module
- Newcomers to modular audio who lack an existing 500 Series rack
Performance breakdown
Sonic Character
Classic API op-amps deliver that signature punch and harmonic warmth.
Signal Integrity
Maintains pristine audio quality even across long, complex cable runs.
Gain Versatility
Wide range handles everything from subtle attenuation to aggressive signal boosting.
Build Quality
Rugged construction meets the high standards of professional studio environments.
Control Precision
Intuitive layout makes fine-tuning levels and polarity shifts incredibly straightforward.
Digital Integration
Effortlessly adds analog depth to sterile, clinical digital recordings.
Key Specs
Output gain range
6dB to 45dB
Balanced input
Polarity switch
20dB pad
Switchable transformer output
Discrete 2510 and 2520 op amps
Proprietary transformers
Signal to noise ratio
110dB
Features
- Amplify and attenuate signals for flexibility
- Add warmth to digital signals
- Drive long balanced cable runs
- Low distortion performance
- Classic API sound
- Robust build quality
What customers say
Customers consistently praise the exceptional build quality and sonic characteristics of this line amplifier. Users frequently highlight its ability to add a distinct warmth and punch, enhancing clarity and presence across various audio sources. Many appreciate its robust construction and the reliable performance it delivers in professional studio environments. The module is often described as a valuable tool for imparting a classic analog sound, making signals sit better in a mix with improved depth and definition. Its consistent performance and high fidelity are recurring themes.
Know before you buy
The 535-LA is designed to provide precise gain control for signals that lack it, such as keyboards, synthesizers, or outboard processors. It acts as a high-quality buffer and amplifier, allowing you to manage levels while adding the signature API sonic character.
Yes. By running digital signals through the 535-LA, you can utilize its discrete 2510 and 2520 op amps and proprietary transformers to introduce the warmth and harmonic richness associated with classic API hardware.
The switchable transformer output allows you to toggle between a transformer-coupled sound, which provides that classic API weight and harmonic character, and a transformerless path for a cleaner, more transparent signal when you need it.
Absolutely. The 535-LA is engineered to drive long balanced cable runs with minimal distortion, making it an excellent choice for maintaining signal integrity in larger studio setups.
The 20dB pad is essential for handling high-level input signals without clipping the internal circuitry. It provides the necessary headroom to accommodate hotter sources before they reach the gain stage.
No, it is designed for high-fidelity performance with a signal-to-noise ratio of 110dB and a total harmonic distortion of just 0.005%. It is built to maintain a clean, professional signal path even when applying significant gain.
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$595