Detail 01
3-band
Low, mid, high. Fewer bands than a 5-band, so you're making broad tonal decisions rather than narrow corrections.
Product detailSKU #1313854583724
API550A Discrete 3-Band EQ
Independent shopping perspective
The Korena take
API's 550A: a three-band discrete EQ in 500-series format. For engineers who want the API console sound on individual tracks.
Strong match
Who this is for
- Adding weight and edge to drums and rock vocals
- Tracking through outboard rather than fixing in the box
- Building a 500-series rack around a console-style tone
Consider the trade-offs
When to look elsewhere
- Anyone without a 500-series chassis and power
- Surgical notch work — the bands are stepped, not continuous
- First-time home recordists who need a preamp first
What matters in use
The specifications, translated
Catalog numbers tell only part of the story. These are the details most likely to change how this product feels, sounds, or fits into a setup.
Detail 02
Discrete circuit
Signal path uses discrete transistors rather than op-amp chips. That's where the thickness on transients comes from.
Detail 03
Stepped frequency selection
You pick from fixed frequency points instead of sweeping. Faster to work with, and recallable across takes.
Detail 04
500-series module
It's a card, not a standalone box. You supply the rack, power supply, and connections.
Detail 05
Proportional-Q behavior
Bandwidth tightens as you boost harder. Small moves stay musical, big moves get more focused.
Final check
Know before you order
- 01No chassis or power supply included — you need a 500-series rack.
- 02One module handles one channel. Stereo means buying two.
- 03Stepped bands mean no continuous frequency sweep; plan your moves accordingly.
Product questions
Before you decide
Straight answers to the questions shoppers most often ask about this product.
01Do I need a 500-series rack for this?
Yes. The 550A is a module with no power supply or connectors of its own. It needs a 500-series chassis to run.
02How many channels is this?
One. A stereo pair means two modules and two rack slots.
03What's the difference between this and the 512c?
The 550A is an equalizer. The 512c is a mic/line preamp. They do different jobs and are often racked together.
04Can I use it on a mix bus?
Yes, but you'd need two for stereo, and the stepped bands make it a broad-strokes tool rather than a fine mastering EQ.
