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TC Electronic Triple C

Dynamics Processor By Paul White
Published December 2000

TC Electronic Triple C

Paul White tests TC's new multi‑mode approach to dynamics, and finds that it's as easy as CCC.

TC Electronic's Triple*C is a 1U rackmount unit providing a variety of digital compression treatments. Its three operational modes provide either Finalizer‑pedigree multi‑band algorithms, SPL Transient Designer‑style envelope shaping or flexible full‑band compression. There are both mono and stereo versions available, each of which has both digital and balanced analogue I/O as standard.

One Comp Or Two?

The graphic envelope display to the right of the window provides a pictorial representation of the envelope attack and release settings when in envelope mode.The graphic envelope display to the right of the window provides a pictorial representation of the envelope attack and release settings when in envelope mode.

In terms of socketry, the mono and stereo units look almost identical, with four balanced TRS quarter‑inch jack sockets for audio, stereo digital S/PDIF sockets, the familiar trio of MIDI connectors and a quarter‑inch footswitch socket (which curiously suggests a live use for the processor). It is the function of the analogue sockets that sets the two variants apart. The mono Triple*C accepts audio signals for processing at the left‑hand input socket, while the right‑hand socket can be used to feed in an external side‑chain signal. Similarly the left‑hand output sends out the processed audio while the right‑hand output sends out an unprocessed signal which can be used to link the operation of two processors together. The dedicated stereo unit uses both analogue inputs for processing audio, though it can be switched to operate in the same way as the mono processor does, if required.

When the side‑chain is activated, the dynamics engine within the Triple*C can respond to the signal the side‑chain input carries in two ways. Either it can base its gain reduction entirely on the level of the side‑chain, or it can derive it from the sum of the combined side‑chain and audio paths — this latter mode makes it possible to compress and duck at the same time. What's more, the side‑chain of the Triple*C allows far more creativity than that of an ordinary compressor, because it can be used in multi‑band and envelope modes as well as in full‑band mode. The way is open for some serious creative abuse here — for example, you could process a pad in envelope or multi‑band mode, but using your drum tracks as a side‑chain signal to create wierd pumping textures.

The S/PDIF digital I/O operates exactly as the analogue inputs, though both analogue and digital inputs cannot be used simultaneously. Although only S/PDIF‑style coaxial sockets are fitted, it is possible to switch the status‑bit format to conform to either consumer S/PDIF or to professional AES‑EBU. One advantage of AES‑EBU is that it doesn't transmit SCMS copy‑protection flags, so if you're working from a master with a copy‑inhibit flag, this just might get you out of trouble. Note, however, that AES‑EBU also discards track start IDs.

The unit can accept 24‑bit digital signals at either 44.1kHz or 48kHz, the machine locking to the incoming sample rate automatically. When using the analogue connections, either 44.1kHz or 48kHz sample rates may be selected. Because not all analogue equipment expects to see the same nominal level, the digital reference level can be set to 2, 8, 14 or 20dBu. In addition to this, there is an analogue trimmer which can reduce the gain by up to 100dB if necessary. When a digital input is being used, digital gain can be applied to the input signal prior to processing and when outputting a digital signal, the bit depth can be reduced (with noise‑shaped dithering) to 20, 16 or 8 bits.

Front Of House

The front panel is far less daunting than you might expect from a dynamics processor with three distinct ways of working. Following the input gain control (really a trim control ranging from ‑6dB to +18dB) is a colourful metering and display section whose viewing angle can be adjusted to suit its placement in your rack. It includes single input and output meters with clip LEDs — on the stereo version, the meters display the sum of the left and right channels. The respective clip LEDs come on when more than one digital full‑scale sample is detected. An indicator shows whether the unit is set to analogue or digital input and there are also indicators to show that the input clock is acceptable and whether the sample rate is 44.1kHz or 48kHz.

The larger horizontal meters show the amount of gain applied to each of the three frequency bands, while the rather neat graphic envelope display to the right of the window provides a pictorial representation of the envelope attack and release settings when in envelope mode. At the bottom of the display is a single‑line, 20‑character read‑out which displays relevant parameter and menu information. This display can also show which of the 50 preset or 100 user patches is currently selected, as well as allowing renaming of user patches.

The knobs in the Dynamic section of the control panel are set up much like a conventional compressor, and are labelled Threshold, Ratio, Attack and Release. However, it's only in full‑band mode that they operate exactly as labelled. Above these knobs are four small buttons with integral status LEDs. The first of these, Multiband Off, activates full‑band compression, while Softlim switches on additional soft limiting within the processor's output stage, in order to keep any residual signal peaks under control as smoothly as possible. The remaining two switches can only be used within multi‑band mode: Peak Sensitive makes the compressor more sensitive to peaks in the signal, and Lookahead allows the compressor side‑chain to get a sneak preview of the input signal 3mS before it hits the gain stage. This latter function allows transient sounds to be controlled very positively, as the compressor knows exactly when to expect them, but increases the processing delay through the unit.

The Spectral section contains controls for both multi‑band and envelope modes, the function of which therefore change depending on whether the Envelope Mode button is lit. A Level control to the right of these adjusts the overall output level (±18dB) to compensate for any gain applied during processing, and it is accompanied by a Bypass switch. Finally comes a dual concentric Parameter/Value dial with a push‑to‑enter action. Adjacent to this is a Menu button that gets you into the Edit menu, I/O setup, and patch Store routines.

<h3>All For One, Or One For All?</h3>

The full‑band compression provided by the Triple*C may not be a highlight of the unit, but it's certainly amply specified for most recording duties, with a full range of ratios between 1.12:1 and limiting, and the ability to set manual Attack and Release times — between 0.2 and 70mS, and between 20 and 2000mS respectively. However, there are no automatic time‑constant settings. In the full‑band mode, the controls in the Spectral section have no effect.

Though the full‑band compression is reasonably well‑specified, I imagine prospective users will be most interested in the multi‑band mode. This is particularly useful in mastering, not only because it helps achieve that sought‑after 'more of everything' sound, but also because it affords a considerable degree of adjustment to different key areas in the audio spectrum. For example, an excessively dynamic bass will be levelled without causing mid‑band or high‑end frequencies to duck out in sympathy, or, alternatively, erratic high end such as may result from a synth filter sweep can be evened out without messing up the bass or mid‑range. Furthermore, multi‑band compression often sounds better on individual sounds than a simple full‑band compressor, so many of the people who purchase the single‑channel version will probably find uses for it as well.

When in multi‑band mode, the Dynamic section controls act as labelled, but only for the centre of the three frequency bands. The high and low bands automatically track the mid‑band, though different preset configurations, available through the Edit menu, allow different relationships between the ratios and thresholds of the bands — nine different options are available, designed to work with vocals and different instruments, and there is also a flat setting (see box on page 114 for more details). Also from the Edit menu you can change the two crossover frequencies between the compression bands. Both points can be adjusted, at third‑octave resolution, between 20Hz and 20kHz, though they cannot overlap. The controls in the Spectral section allow you to adjust the relative output levels of the outer frequency bands relative to the mid‑band.

The envelope mode is used to modify the attack and release characteristics of transient sounds such as drums. In some ways, this attempts to do what the SPL Transient Designer does so well (see my review of the Transient Designer 2 in SOS August 2000). However, where the SPL process is largely level‑independent, the TC Triple*C works on a threshold system so that the only signals processed are those exceeding the Threshold setting on the front panel — 'Trig' lights up in the display when the incoming signal is high enough to trigger the envelope effect. The Spectral section controls alter the amount of gain applied to the attack and release portions of the sonic envelope, while the Attack and Release controls alter the speed with which gain is added to or subtracted from the signal. Note that the gain applied to a sound's envelope can be either positive or negative, enabling drums and other percussive sounds to be made to sound more damped or more live.

To round off the sonic processing, a less obvious sonic feature is tucked away in the Edit menus. TC's DRG, or Digital Radiance Generator to give it its full title, is a type of tube‑warmth emulator and it can be set in eleven stages from zero to ten.

In addition to its audio processing capabilities, the Triple*C both transmits and receives MIDI data. Not only can it be controlled remotely using controller numbers on any MIDI channel, but it can also manage the usual SysEx dumping and loading of patches. All compression parameters can be controlled over MIDI, and patches can be changed using Program Change and Bank Change messages (the latter using Continuous Controller 32).

Using The Triple*C

It might sound like a joke bra size from a Carry On film, but the Triple*C is a very serious piece of equipment — though it does lift and separate in an impressive way! Nevertheless, TC have simplified the control system to make it very easy to use. Though these simplifications may deprive the more advanced user of some degree of control, in most instances the controls that are provided work perfectly well. Excessive excursions are caught by the soft limiter when it's switched on, but if you deliberately push the signal too hard against the limiter, it starts to sound a bit unrefined. The best bet is just to allow the limiter lamp to flicker briefly on signal peaks.

The multi‑band compression works a treat, and although you can force it to produce unnatural pumping effects, you have to really lay it on thick. With sensible levels of gain reduction, the process sounds very natural, with both mixes and individual sounds becoming a lot louder and more solid‑sounding than before they were processed. It was instructive to compare the sound of a complete mix being processed in full‑band mode, and then to switch to multi‑band. Straightaway the sounds within the mix became much better separated and more clearly defined, and you could add a lot more processing before the side effects started to show. Even the Digital Radiance gizmo is nicely subtle, yet still manages to add the necessary punch and detail to a signal without making it sound fuzzy or deliberately messed around with.

In full‑band mode, the compressor works like a good‑quality, conventional analogue compressor with no obvious vices. You can make it sound polite or you can make it pump — it's all down to how you adjust it. Having said that, I'm not quite sure why look‑ahead or peak sensing aren't available in this mode. I'm also not sure how often you'd use full‑band mode after hearing multi‑band. Perhaps it's just there so you can compare it to multi‑band!

The envelope mode works best on drums and percussion, but you really must treat it with restraint. It only takes a few dBs of attack gain to really add snap to a drum kit whereas the release gain can either make the drums sound very heavily damped or it can set the tail end of the sound pumping so much that the drums actually get louder after they've been hit. Too much attack gain and even the tamest drum sounds are smashing against the limiter. However, this mode can often salvage unsatisfactory drum sounds or change the character of an existing recorded drum part.

Triple Strength

The Triple*C is a very powerful and nice‑sounding dynamics processor, the operation of which has been designed to be as simple as possible for inexperienced users. Its multi‑band mode is its best asset, but the envelope mode is also a great 'fix it' tool for tweaking drum sounds that don't quite cut it. The full‑band compression mode also works perfectly well, but I can't think of many occasions where it would be more useful than multi‑band, unless you want to create deliberate pumping effects.

Of course, with power comes the potential for abuse, and no matter how many times we say it, there's always somebody out there who thinks that multi‑band compression gives them the license to make everything as loud as is humanly possible, regardless of the trade‑offs. Certainly this box can make things sound very loud (though using a really good mastering peak limiter afterwards might squeeze a few more dBs out of a mix), but it also helps make sounds knit together properly and makes it very easy to adjust the spectral balance of a mix. It's equally good with single sound sources such as voices, drums or guitar where you want to maintain a high level of energy and definition without ruining the true character of the original.

As an insert compressor, the mono unit is fine, but once you've tasted multi‑band compression, I think you'll probably want to have the facility to use it in stereo as well, so I imagine that most people will go for the stereo unit. Whichever you decide on, though, I don't think you'll be disappointed in either how the Triple*C sounds or how easy it is to use.

Style Counsel

In multi‑band mode, depending on what type of material is being processed, you may need different ratio, threshold or time‑constant settings in the three frequency bands. But, without a lot of prior experience, this can be very difficult to set up, so TC have removed the ability to adjust each separate band, other than in terms of output level, to avoid confusion amongst less experienced users.

However, in order to accommodate different types of programme material, they have included a set of 'template' compression styles that include the necessary offsets between the parameters in the different bands. Therefore, when the mid‑range band is adjusted by the user, the outer two bands are changed proportionally according to these style settings. Though this doesn't allow the experienced user as much flexibility, it does enable the less confident user to achieve good results over a wide range of source material.


  • About as simple to use as it can be.
  • Side‑chain input available.
  • Envelope mode provides a powerful tool for drum sound modification.


  • More sophisticated users may wish for independent control of all the compressor parameters within multi‑band mode.


The Triple*C is a sensible compromise between flexibility and ease of use. Its multi‑band compression mode suits most individual sounds or mixes while the envelope mode is good for perking up limp drum sounds.