Tuesday, May 23, 2023



API invented the 500 series format for signal processors. Each single slot module position is actually the same size that API uses in their world class mixing consoles. The original 6-slot API lunchbox provided a method for users to carry these powerful tone shaping tools from studio to studio.

So how does the modern API 10 slot rack compare to todays competition? Read on and discover why we spent more to get this quality API component. 

The API company started building components and mixing consoles in the 1960's. In the 1970's the company was in the right place at the right time with a powerful modular product range. The mixing consoles utilized a variety of standard modules which plug in to a hardware frame. It was only a short step to making lunchboxes to house and power console modules like EQ and compression. 

Today you can find all sorts of signal processors designed to fit in the 500 series format. The simple little lunchbox idea has spawned a whole cottage industry of chassis and modules to choose from. 


Excellent quality, professional construction, robust outboard linear power supply and it's the industry standard because they invented the format. When you go to sell a piece of gear the brand matters and the API name demands respect from years of experience. 

Nylon cable ties hold the robust external API 10-slot Power Supply

I love the way modules fit in the API rack. On lower priced racks I've tried the modules are difficult to align and even tougher to get the mounting screws to all line up. One brand I encountered made the slots in their rack 2mm too narrow so modules don't fit right. Another inexpensive rack I tried induced hum from the inbuilt power supply. 

The only active component in a 500 rack is the power supply, the rest of it is just a hardware frame/chassis to hold the modules, provide them with power and give the user inputs and outputs for the modules installed. 

If you're thinking about getting your first 500 frame the API may look expensive but the quality professional performance will be worth it. The remote L200 API power supply is designed to quietly light up the frame and the modules installed with ultra-reliable 24/7 operation. 

I use an API 10 slot rack for my meter bridge, I mounted JLM stereo peak reading meters in the 10 slots. The power supply for this rack lives on the floor down under the mixing console. 

API 10-slot rack used as a compact meter bridge

I use another API 10 slot rack to house my new Midas EQ and Compressor modules along with our new AMS RMX16 reverb. I used nylon wire ties to affix the power supply to the bottom of the 19" rack the API chassis is mounted in. 

API 10-slot rack in Producer Side Car


When it became clear the studio needed another rack mountable 500 frame to hold the new AMS reverb I immediately set about ordering the API. After briefly looking at other brands (just to see what was out there) it was easy to order the API, it's quality, I knew it would work and when/if I ever go to sell it the API brand means I'll probably get all my investment money back due to inflation. 

Considering all the performance and reliability factors the API is the right choice for me. 

Good Music To You!

©2023 Mark King.  It's not ok to copy or quote without written permission.