API 5500 Dual EQ with Range Switch (Special Order Item)

The 550B equalizer, which allows for more precise settings than the 550A, is luxuriously rack-mounted in two channels.

Each can be used independently, so they can also be used for recording.
Additionally, a range setting is available exclusively for the rack type, allowing you to adjust the volume between "1/4" and "1/2," allowing for more precise settings and more aggressive sound creation.
This is an all-around EQ that can be used in a wide range of situations, including recording, mixing, and mastering.

Features: Follows the traditional API550B equalizer design
- 2-range gain selector switch that allows you to change the gain step
- Also functions as a 550B, 550D, or 550M
- Peak/shelving switches on high and low sections
-Hardwire bypass function
- Supports balanced input and output via XLR connectors
- Supports unbalanced input via 1/4 phone jack
・EQ IN/OUT switch

We recommend that this product be powered by 117V.

The equalizer circuit used in the API5500 is derived from the all-time classic API550 equalizer. The API550 was designed as an equalizer module for a recording console, so its input specifications were unbalanced. As compact mixing console designs became more common, the mixing module format presented numerous operational challenges. The API5500 was developed to overcome these limitations. Its balanced inputs, hardwired bypass function, built-in power supply with noiseless mute, and various range controls make it the ideal tool for mastering, a field that has become increasingly important in recent years.
Like all API products, the API5500 uses no integrated circuits in the main path. Gain is handled by the hand-built, discrete 2520 op amp. The balanced input stage is handled by the 2510 discrete op amp, which has similar specifications to the 2520 but is capable of higher output power. The signal from the API2520 is then routed through the proprietary API2503 output transformer, achieving a clipping level of +30dBm. This generous headroom allows for ample gain in the main path without the need for additional preamplifiers.
A new feature of the API5500 is the Range Control. The preset range control between 1/4 and 1/2 allows for more precise sound adjustment. This function plays an important role in adjusting complex 2-mixes and final mastering.
Another new feature of the API5500 is the hardwired bypass. In this mode, the input and output are directly connected. This makes it suitable for use in broadcasting stations, as it ensures output even if the power is not turned on initially or goes down during operation. Of course, there is no noise when switching.
The signal from the XLR input is connected to an active balanced circuit. The XLR output passes through an output transformer, which ultimately adjusts the input impedance. Another advantage is that there is no polarity switch, so there is no need to worry about polarity differences between devices connected before and after.