New Music Gear Monday: API MC531 Monitor Controller

New Music Gear Monday on Bobby Owsinski's Music Production Blog features the new API MC531 monitor controller

There are many pretty good computer audio interfaces on the market, but if you’re really serious about the sonic quality of what you’re listening to, you have to up your game. Yes, there are good choices in the higher quality ranges as well, but a new entrant with a long pedigree is the legendary console company API with its new MC531 monitor controller.

Monitor Control

The MC531 offers a stand-alone version of the monitoring functionality built into the center section of API’s legendary analog consoles, so it has the same look and feel but it’s loaded with features too. Just looking at the monitor section first, there’s a big blue control room level control (called C/R LEVEL) with a set of stereo LED ladder meters that go from -24 to +24 (that’s a lot more headroom than you’ll find on most controllers). There’s a DIM switch with a level control, and a series of switches that provide CUT (monitor mute), MONO, and LT and RT (left and right speaker mutes). Then there’s a TALKBACK button that’s routed to the headphones (more on that in a little bit) along with a gain control and top panel mounted microphone. All switches are lit when they’re toggled on, by the way.

One interesting switch here is labeled API. This routes the monitor outputs through an API 2520 op-amp and custom transformer output stage when engaged to give you that authentic API console sound.


For outputs there’s a MAIN monitor on/off switch, and facility for two alternate speaker outputs labeled ALT 1 and ALT 2. Both of these also have top mounted trim controls. Then there’s a dedicated subwoofer output labeled SUB (also with a trim control), that can be programmed to link with MAIN, ALT 1, and ALT 2 monitor selections. The SUB out is a full frequency signal output to the subwoofer and is not bass managed or bandwidth limited. Presumably your subwoofer will do that.

There are two dedicated headphone outputs each with on/off switches and level controls. The amplifier circuit is the same one found in API consoles such as THE BOX, 1608, 1608-II, and 2448. Each has a selector switch for the control room output or a different input to be the input source.


The MC531 has a wide array of input sources available. It can connect to your computer via a USB connection (with an on/off button labeled ST-4), AES input (also connected to ST-4) or Bluetooth (ST-5), which is super convenient if you want to play back something off your phone or external computer. There are also 4 additional stereo analog inputs as well, labeled ST-1, ST-2, ST-3, and ST-5. Yes, ST-5 can be used for Bluetooth, but it also has a mini-jack connection available as well.

When you look at the cost of high-end monitor controllers, the API MC531 is actually pretty reasonably priced at $2,495. It’s loaded with features and gives you something that no other controller can – that API console sound.

You can find out more here.

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