collapse expand iconDescription

The 550A special edition discrete three-band EQ in a limited edition cream color brings back the cherished sound of an analog console classic. With its fully discrete signal path and proportional Q circuitry, the 550A shapes your tone with musicality and vintage character. Sculpt your sound with the 550A's three bands of equalization, shelf/peak switching on bands 1 and 3 provides versatility for dialing in lows and highs and the proprietary bandpass filter carves out problem frequencies with precision. Whether you need gentle sweetening or more dramatic contouring, the 550A special edition helps craft your ideal tone.

Shape Your Sound With Three Bands of Proportional Q EQ

At the heart of the 550A is its three-band equalizer, giving you powerful yet musical tone control. The low, mid and high bands each provide up to 12dB of cut or boost at optimized frequency centers selected by API. This lets you precisely tailor bass, midrange and treble to suit your needs. API's renowned proportional Q circuitry narrows the Q at extreme cut or boost settings which prevents drastic spikes that could degrade your sound. The result is an organic, musical response perfect for instruments and vocals.

Add Versatility With Shelf/Peak Switching

The 550A increases your options with shelf/peak switching on the low and high bands. In shelf mode, you can gently shape the overall balance of bass or treble frequencies and simply switch to peak mode for more focused boosting or cutting at a specific frequency center. Dial in the perfect low end for a bass guitar or add shimmer to vocal highs - the 550A puts customizable tone shaping at your fingertips.

Clean Up Your Mix With the Bandpass Filter

The 550A also includes a proprietary bandpass filter, providing a powerful tone-carving tool. With a 12dB per octave slope, you can isolate and attenuate problematic frequencies that are muddying up your mix. Sweeping the filter allows you to quickly find and tame resonant peaks or other anomalies, resulting in a tighter, cleaner mix with clarity even in dense arrangements. Whether you need crisp percussion, a smooth vocal or clear electric guitar tone, the 550A's bandpass filter can help.

Harness the Musicality of API's Discrete Design

As an all-discrete design, the 550A delivers the renowned warmth and presence of an API console channel. Its signal path uses no integrated circuits, providing vintage analog magic, while the proprietary 2520 op amp and transformer-coupled outputs further enhance the musicality. Thanks to its optimized design, the 550A fits perfectly into your 500 series rack while retaining the sound and performance that made the original a legend. Bring home the EQ that generations of engineers have relied on to shape world-class recordings.

API 550A Special-Edition 500 Series Discrete 3-Band EQ

collapse expand iconFeatures

  • Discrete 3-band EQ with reciprocal equalization at 21 points
  • Seven selectable frequency centers per band
  • Up to 12dB of boost/cut available per band
  • Limited edition cream color

collapse expand iconSpecs

  • Number of Channels: Single
  • High Pass Filter: Yes
  • Low Pass Filter: Yes
  • Q Type: Proportional Q
  • Freq Range High: 2.5kHz-20kHz
  • Freq Range Mid: 200Hz-5kHz
  • Freq Range Low: 30Hz-400Hz
  • Frequency Response: 30Hz-20kHz
  • Depth: 7.25"
  • Weight: 2 lbs.