TC Electronic Konnekt 24D Audio Interface

Do we really need another FireWire audio interface? TC thought so, and they have indeed come up with a novel twist on the audio interface concept.


I/O means two front panel, XLR+1/4" mic/instrument pres (switchable to rear line level 1/4" ins), two additional line ins, and four line outs; in digital-land, there’s MIDI, optical (S/PDIF or ADAT — standard 44.1/48kHz, and SMUX for four channels at 88.2/96kHz), as well as S/PDIF coax I/O. A phantom power switch turns on a real +48V for both ins. Of the two headphone jacks, one works as usual, while the other mutes outputs 3/4 when you plug in the phones.

The K24D can be bus- or AC adapter-powered. There are two FireWire ports, which let you chain up to four K24Ds. It’s worth noting that I took the thing apart (the construction is top-notch), and there’s shielding within shielding — this box won’t dirty up your electrical environment.

The cosmetics are very northern Euro: Shiny metal casing, white front panel with a shiny clear plastic overlay, oval knobs so they’re easy to grasp without disturbing other knobs, and a visually appealing LED “light ring” around a multipurpose control whose function depends on what you select with a front panel pushbutton.


Here’s where it gets interesting. The mixer applet (Figure 1) provides the usual direct monitoring and routing options, but also has edit pages for two very hip processors that run on the K24D’s internal DSP: the Fabrik C channel strip (EQ and dynamics) and Fabrik R (algorithm-based reverb). These sound wonderful — the reverb (fed by send controls) runs circles around just about any plug-in that comes with your host of choice, and the dynamics control and EQ are both crisp and tight.

They also have “outside the box” interfaces that involve dragging around what seems like pieces on a game board; these each tend to control multiple parameters , so you just drag around until things sound good (or look at the numericals if you want old school).

But it’s bonus time: The K24D can serve as a stand-alone processor (yes, stick the reverb in your mixer’s aux bus, or use the dynamics in a channel insert). You can also use either effect as a send/receive effect in software hosts (or with Cubase SX3 and 4, as a pseudo-VST plug-in); this involves sending signal out of the host, into the K24D, then bringing it back in again as if monitoring a live input. And registered owners can download Assimilator (curve-matching software), which is an actual VST plug-in.

However, when the DSP-based processors are used with a host, you can’t instantiate multiple instances like a “real” plug-in, and because you’re leaving the host and returning, any system latency matters. At 96kHz, you have to choose between the Fabrik C or R; furthermore, the two Fabrik C processors are wedded to channels 1 and 2, so you can’t insert them on inputs 3/4, or any of the digital inputs. Given how much the processors bring to the party, I won’t complain but be aware there are some limitations.

As to latency and stability, TC is to be commended for issuing a couple driver updates in quick succession that solved some vexing problems. With driver 1.03 installed, the K24D has been a reliable performer at 128 samples, and in some cases, goes down to 64 samples without a hiccup. That’s good stuff, especially if you’re going to use the effects as send/receive effects with your host.


I expected a competent, well-engineered product, but this one threw me a curve. The sound quality is exceptionally good, even in a world where the bar for audio quality keeps getting raised. The character is clean and defined; from mic pre to headphone outs, sonic detail is the name of the game.

The DSP is exceptional, it’s nice to have real MIDI I/O (no breakout cable), and the ADAT in is a great “trap door”: I patched in a PreSonus DigiMAX FS and voilà, eight extra mic pres (a cheaper route than chaining three more K24Ds if all you want is more mics).

I’ve worked extensively with the K24D over the past several weeks, and it’s passed every test I could throw at it. Thumbs way up.

Product Type: FireWire audio interface and stand-alone signal processor.
Target Market: Project studios who are willing to pay a bit more for superior fidelity and onboard DSP processing.
Strengths: Sounds great, including the processors. Plenty of I/O. Well built. Solid drivers. More flexible than the average interface. Can stack up to four units. Innovative thinking.
Limitations: DSP usage is limited in various ways. Assimilator plug-in not yet Mac Intel compatible.
Price: $625 list