Home » Recording Resources » Featured Reviews » December 2023: KIT Plugins BB A5

Vintage vibe, Blackbird style

Review by Bill Stunt

KIT Plugins has once again raided the racks at Nashville’s extravagantly equipped Blackbird Studio. This time, they’ve put their hands into the sonic cookie jars of the studios B and D rooms—specifically, each room’s API Legacy consoles. The result is the new KIT Plugins BB A5.


A Channel Strip and Beyond

The BB A5 is modeled after the API (Automated Processes Inc.) Legacy consoles that are prized for their punchy, aggressive and mid-forward sound.

More than just a channel strip plugin, according to KIT, the concept was to provide the sonic and physical essence of the console with an authentic analog-like experience.

To deliver this, the developers modeled the sonic nuances of multiple channels from each of Blackbird Studio’s pair of API Legacy consoles. Along with the 212L preamp, the plugin includes a choice of three classic EQ modules (just like swapping 500 Series modules in your DAW), analog noise modeling and the path to the master bus of the console.

A Distinct and Familiar Look

The gorgeous interface graphically represents the desk’s distinctive input, EQ, fader and output modules, and the unique blue and silver API-inspired knobs.

Along the top of the interface are global input and output controls, a preset section with A/B swap and an options menu to set oversampling, turn on tooltips and access the manual.


The channel strip starts with what would typically be the input trim/gain knob. Here it functions as a preamp sensitivity knob that, rather than increasing the apparent volume, drives the preamp stage into transformer-type saturation/compression. It can be set to Mic or Line level—where it is disabled. There is also a 20dB pad and a polarity switch.


None Shall Pass

A pair of pass filters follows with a 6dB per octave high-pass filter (20 to 600 Hz) and a 12dB per octave low-pass (20 kHz to 300 Hz). This section is rounded out by an LED-style input meter.

All Things Being Equalizers

As mentioned above, the EQ module can be loaded with a choice of a 55A, 55L or 56L EQ module. The 55A emulates the classic and much-loved parametric 550A three-band EQ. The 55L is based on the similar four-band 550L (and 550B). The 56L is modeled after the 560 ten-band graphic EQ.

The 55A and 55L feature the same fixed high (2.5 kHz, 5 kHz, 7 kHz, 10 kHz, 12.5 kHz, 15 kHz and 20 kHz) and low (30 Hz, 40 Hz, 50 Hz, 100 Hz, 200 Hz, 300 Hz and 400 Hz) bands that can be optionally set as bell or shelf filters.

The 55A mid-band is a bell filter with fixed frequency points at 200 Hz, 400 Hz, 600 Hz, 800 Hz, 1.5 kHz, 3 kHz and 5 kHz. The 55L EQ splits the mid frequencies into high-mid (800 Hz, 1.5 kHz, 3 kHz, 5 kHz, 8 kHz, 10 kHz and 12.5 kHz) and low-mid (75 Hz, 150 Hz, 180 Hz, 240 Hz, 500 Hz, 700 Hz and 1 kHz) bands with fixed frequency points. The 55A has a unique Band Pass filter, which attenuates signals below 50 Hz and above 15 kHz.

The 56L graphic EQ sliders adjust +/-12 dB at frequency points of 31 Hz, 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1 kHz, 2 kHz, 4 kHz, 8 kHz and 16 kHz.

Unique to the plugin, the 55A and 55L EQ pots can be stepped just like the hardware or continuously variable.

To Hum or Not To Hum

The output module has controls for introducing three levels of analog hum. This can be linked so all plugin instances have the same setting. Next, there is a switch to route the virtual signal into the master bus section—a significant component of any console’s sound. A large output fader determines how hard you drive said bus. The plugin is rounded out by a second LED output meter.

The Lowdown

Throughout the years, I’ve worked with both API consoles and various outboard modules. I love the aggressive, punchy, mid-forward sound that to my ears is less dense and edgier than the classic British sound. I’m happy to report that the plugin does a great job of representing this classic sound.

The top-end of the equalizers has a nice bite without being brittle. The low-end is defined and authoritative. The mids rule the roost. The magic is in the proportional Q design, where the Q narrows with more significant boosts and cuts. The overall curve remains smooth and “musical,” even at extremes.

The equalizers are sonically similar, with the 55L sounding slightly more pristine. The hardware has a different op-amp that may account for that along with the added mid-frequency band. The 56L was a revelation as I have never had the chance to use the hardware version. It offers a smoother sound with very attractive EQ choices. It’s great for thinning out muddiness, allowing the mid-frequencies to come through more coherently and shaping the high-end.

I was tracking some bass tracks concurrently with working on this review. Bass is a source that shines with a bit of “Legacy” mojo. Goosing the high-mids at 1 kHz added a lovely bite. A good bump at 100 Hz added weight and authority, and a touch of 5 kHz gave it a nice sheen. The bolder the boosts, the more resonance and perceived aggression. Driving the preamp added harmonic content that pushed the bass forward with increased intelligibility. It can also get deliciously aggressive, which is nice on bass, electric guitar, snare and vocals.

Pleased with the bass results, I quickly confirmed similar results on the drums, guitars and vocals. I’m looking forward to using the BB 5A on the final mix.

The analog hum option is quite subtle, even at the highest setting and becomes more noticeable as you add more instances. The master-bus emulation is the icing on the cake. Again, it’s a subtle effect, but it really adds a remarkable coherence and analog signature to the sound when placing multiple instances of BB A5 across the tracks in your session.

Wrap Up

Perhaps you might be thinking, OK, but do we really need another API-inspired plugin? I would say, absolutely! Once again, KIT Plugins delivers a great new take on a classic sound by focusing not on a brand but on a specific specimen in use daily in a world-class studio.

I also can’t wait to see what in the “to die for” Blackbird racks KIT turns to next for inspiration.


Price: $150

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