Digital compressors have never been highly regarded. Despite their obvious advantages over analog compressors automation, more precise control, and program

Digital compressors have never been highly regarded. Despite their obvious advantages over analog compressors — automation, more precise control, and program storage (thus repeatability) — many recordists feel that they just don't sound as good. Fortunately, as with all things digital, the technology has improved by leaps and bounds, and the bad rap for digital compressors might finally be on the wane.

TC Electronic's latest digital signal processor, the Triple-C multiband compressor and envelope (see Fig. 1), could well have the right stuff for winning over even the most die-hard analog curmudgeon. In addition to full-range dynamics processing, the voltage-controlled-amplifier-based Triple-C provides two additional compression modes, a sidechain function, and several new music-enhancing features not typically found on compressors. As for repeatability, the Triple-C holds 50 factory presets in ROM and an additional 100 user presets in RAM.

The Triple-C comes in two versions: stereo and mono. For this review, I tested the mono version in my personal studio.


The Triple-C's front panel is logically laid out in six sections: Input, Multispectral LCD, Dynamic, Spectral Levels, Makeup Gain, and System. The Input section provides a Level knob with decibel markings at -6, 0, +3, +6, +9, +12, and +18.

The Dynamic section provides control of the usual compressor parameters through four dedicated, continuously variable knobs labeled Threshold, Ratio, Attack, and Release. The Threshold knob has decibel markings at -40, -30, -20, -15, -10, -5, and 0, and the Ratio knob has markings for 1:1, 2:1, 3:1, 4:1, 6:1, 8:1, and Ω:1 ratios. The Attack knob has markings at 0.2, 0.7, 2, 5, 10, 20, and 50 ms. The Release knob's millisecond markings are at 20, 100, 200, 500, 700, 1k, and 2k. Also in the Dynamic sections are four buttons labeled Multiband Off, Peak Sensitive, Softlim, and Look Ahead.

The Spectral Levels section contains two detented knobs labeled Lo-Band and Hi-Band, each with markings for Min (counterclockwise), Normal (straight up), and Max (clockwise) settings. The section also has a button labeled Envelope Mode. The Makeup Gain section provides a Bypass button and a Level knob with decibel markings at -18, -12, -6, 0, +6, +12, and +18.

The System section comprises two concentric knobs and a Menu key. Use the outer Parameter knob to scroll between parameters and the inner Value Set/Enter knob to change values. You can also turn the Value Set/Enter knob to scroll through menu selections (after pushing the Menu key) or push it to approve actions such as recall and store.

The multispectral LCD is large, well organized, and pleasing to the eye. Divided into four sections, the LCD clearly shows all the information you need. On the left is a pair of vertical meters that display input and output levels. A prominent meter in the display's top-center section shows total gain through the unit and, when the unit is in Multiband mode, gain reduction for each band. That section also shows the input source (analog or digital), sync status, and sampling rate (44.1 or 48 kHz), and provides indicators for Link mode and MIDI receive. The Envelope window, located at the top right, uses diagrams to show the shape of the attack and release. A fourth section along the bottom of the display shows the patch name and corresponding parameter value in large type, which is nice considering how difficult it is to read the front panel's silk-screened labels.

The stereo Triple-C's rear panel provides two balanced ¼-inch TRS inputs; two balanced ¼-inch TRS outputs (the ins and outs also accept unbalanced connections); S/PDIF I/O on RCA jacks; MIDI In, Out, and Thru ports; and a ¼-inch external control jack for connecting a bypass pedal (see Fig. 2). The rear panel of the mono Triple-C differs slightly: in place of the stereo version's second analog I/O is a sidechain input and direct output (for linking two mono units). Both versions (stereo and mono) have an internal power supply and provide a standard IEC connector on the back panel for attaching the power cord.


The Triple-C's three modes of operation are Full-range, Multiband, and Envelope. In Full-range mode, the Triple-C functions as a conventional compressor. You can adjust attack times from 0.2 to 70 ms (not 50 ms, as the front panel indicates) and release times from 20 ms to 2 seconds.

The Triple-C provides a greater range of compression ratios than most compressors, ranging from 1.12:1 (not 1:1, as labeled on the front panel) to 64:1 and on to Ω:1. As you change the ratio, the values show in the display.

Multiband mode splits the input into three user-defined bands — designated Lo, Mid, and Hi — and compresses each band independently. In that mode, the threshold, ratio, attack, and release controls affect the Mid band. The other bands are compressed with the same ratio, attack, and release, but only if they exceed the threshold.

Spectral Levels boost or cut the Lo and Hi bands; think of Spectral Levels as makeup-gain controls for the Lo and Hi bands. If the one band is being squashed, you can use Spectral Levels' controls to bring its level back up a bit; they allow very precise tweaking and subtle shaping of harmonically complex signals.

Multiband mode also provides the Look Ahead feature, which delays the output by 3 ms. With Look Ahead engaged, the Triple-C analyzes the incoming signal, and if it sees a peak that exceeds the threshold, it squashes it before it appears at the output. Because most people don't perceive such a short delay, the attack time in Look Ahead is virtually 0 ms. (I wish this feature were available in Full-range mode.) One minor annoyance was that my test unit exhibited an audible pop every time I pressed the Look Ahead button.

Peak operation is another feature that's available only in Multiband mode. The Triple-C is basically an RMS-based compressor, meaning that it responds to the average level of the incoming source material. The Peak Sensitive switch lets you change from RMS to Peak operation, letting you use the unit as a peak limiter.

Envelope mode is unusual, if not unique, in that it lets you independently adjust the signal's attack and release times. Envelope mode makes it possible to shape a signal's dynamic content throughout its duration, which is pretty cool. I used it successfully to soften the pick attack on a bass-guitar track, accentuate the pick attack on a biting electric-guitar track, and dry up a wet signal somewhat by dipping the reverb tail.

The Envelope mode's effect was most apparent when I used it to add attack to a snare drum played with brushes. The range of settings let me soften the brush hits to mush, make them crack like a stick hit, and dial in any sound between those two extremes. Be careful when monitoring at high levels, though; with a fast attack and the threshold set near 0 (thus affecting all signals), attack transients can be sharp enough to damage your speakers.


The Triple-C's concentric knobs let you recall, edit, and store factory and user presets easily. To recall a preset, scroll with either knob until you find the desired patch and then press the inner Value Set/Enter knob. When you've finished editing the preset's parameters, select Store from the Edit menu. You then have the option of storing that patch in the first available User patch location. If you wish to overwrite one of the 100 User locations, just scroll to it and save. Before saving, the Triple-C prompts you to name the patch. You can archive User patches through a MIDI Bulk Dump.

Pressing the Triple-C's Menu button provides access to all menus. The Edit menu lets you change the crossover frequencies of the Lo and Hi bands, select patch categories (vocal, percussion, bass, horns, and so on), and enable or disable the unit's sidechain.

The I/O menu provides access to a slew of options. You can choose analog or digital input source, clock settings (44.1 kHz, 48 kHz, or external), AES/EBU or S/PDIF operation, digital input levels, analog output levels, and dithering alternatives. The I/O menu is also where you find the Triple-C's MIDI functions — MIDI channel, Control Change (CC) enable, Program Bank (where you determine whether CC messages call up factory or user presets), Bulk Dump, and SysEx ID — as well as the means to enable the Link function when chaining together two units.

The Triple-C's MIDI implementation affords access to parameters through Control Change messages. That useful feature helps when a single compression setting isn't sufficient for a whole track. For example, you could automate the unit with MIDI commands to provide really hard compression on the lead vocal during the chorus and gentle compression during the verses. Furthermore, you could automate changes in tonal characteristics by changing the Hi-Band and Lo-Band settings in Multiband mode.

The manual also lists Bypass and View Angle in the I/O menu, but those options were missing from early versions of the Triple-C, including the one I tested. If you happen to have one of those early units, TC will update it to the current software revision for free.


The Triple-C's Sidechain function works like any compressor sidechain, letting another device — an equalizer, for example — control how the Triple-C behaves by triggering the compression.

When you select Add from the menu, the internal settings and the external device share control of the compression — equally, using a summing amplifier — which kicks in when the combined signal of the input and the sidechain exceeds the threshold. (I was disappointed that the Add function wasn't explained more adequately in the manual.)

You can also use the sidechain input to link two mono Triple-Cs for stereo operation. Connect the direct out of the master Triple-C to the sidechain in of the slave Triple-C and vice versa, connect MIDI Out from the master to MIDI In on the slave, and then select Link On in the I/O menu on both units. In stereo mode, both units respond to the signal present in the master unit. The master's threshold determines when compression kicks in on both units, providing operation identical to that of a stereo compressor.

You can also set up a dual-mono mode by making only the MIDI connection and again selecting Link On in the I/O menu. In dual-mono mode, you set the parameters for both units from the master, but each unit responds to its own inputs. Dual-mono and stereo mode are both useful for compressing two tracks identically. Unfortunately, because I had only one mono Triple-C, I was unable to test those functions.


Like most studio owners, I have my favorite compressors for specific applications. Some have tubes, others have solid-state circuitry, and a few are computer plug-ins. For example, I typically use Daking 91579s on drums, bass, electric guitars, and vocals. The Bomb Factory Classic Compressors plug-ins — the LA-2A and 1176 — also get a lot of use on drums and guitars. For recording acoustic guitars, I usually prefer the dbx 166. If I want to add just a little compression to a mix, I patch my Audio Design Compex Limiter across the stereo bus. (For a comprehensive tutorial about compression and characteristics of different types of compressors, see “The Big Squeeze” in the February 2001 issue.)

The Triple-C stacked up well against the other compressors in my studio, and it proved extremely flexible, working well on everything I tried. It has become my first choice — or it at least receives equal consideration with my usual standbys — for several applications, including bass, acoustic guitars, vocals, and percussion.

To test the Triple-C, I first recorded a variety of instruments and vocals with no EQ and compression. I then patched the Triple-C into a channel insert and played back my tracks to see how the Triple-C performed.

I started by dialing in factory presets and tweaked from there. With Fast Bass (a Multiband preset), fiddling with only the threshold and makeup-gain controls produced desirable results for a pounding rock piece. Tube Bass Comp worked well right out of the box. For electric guitar, I chose the Natural GTR preset with no alterations other than slight adjustments to the Spectral Levels, which helped place the guitar track in the mix.

Heavy guitars benefited from a generous dose of Multiband compression with a slow attack time, especially when I boosted both Lo and Hi bands a bit, leaving a small notch in the middle. I also achieved a very nice U2-like guitar sound using the Light GTR Comp patch with a fast attack time and a high ratio. Background Vocs added silkiness to layered vocals and made me wish I had two units to process the voices in stereo.

I tried cutting some tracks with the Triple-C in the signal chain. I plugged in my Bass Pod's balanced output and turned off the Pod's compression. The bass guitar growled nicely, and the Triple-C smoothed out its sound. Loud passages were held in check, and quiet passages exhibited both pick attack and finger noise — just what I wanted. Also, thanks to the Multiband compression containing the boomy, low-end stuff, I was able to print the signal hotter to disk.

All of my instrument tracks were improved by various amounts of compression ranging from subtle to over the top, especially in Multiband and Envelope modes. Generally, the factory settings were fine starting points for further tweaking, but because every compression task calls for its own settings, the ability to store 100 user-programmable patches is extremely useful.


One of the Triple-C's most outstanding features is the Digital Radiance Generator (DRG; accessible through the Edit menu), which adds second-harmonic distortion to the signal to simulate tube warmth. On acoustic guitar, the effect was subtle but nice; it added a richness to the sound that I really liked, and afterward the track blended better with the other tracks. The DRG is also a compelling effect for background vocals, adding a nice airy quality.

Because the DRG is under MIDI control, you can process different sections with varying amounts of “radiance” during mixdown. Although I didn't have access to a tube compressor for comparison purposes, I really liked the DRG's sound.


I have a few minor complaints about the Triple-C's user manual. In some places, the writing is difficult to understand because of poorly constructed sentences and translation errors. For example, when describing the Multiband mode's parameters, the manual reads, “By dividing the source material into three frequency areas you can avoid that peaks at certain frequencies controls the compression of the entire signal.” Huh?

Another problem is that the manual's front-panel diagrams are difficult to read. Although the manual includes a brief, helpful introduction to compression and basic guidelines for novices, it inadequately explains or arbitrarily omits some features.


The Triple-C is a reasonably priced, flexible, great-sounding digital compressor that is at home in pro and personal studios. Its three modes offer functionality I haven't seen in one box before. The Triple-C performs well in Full-range mode and merits consideration as the primary compressor for any decently equipped studio for that mode alone. In Multiband mode, however, the Triple-C really distinguishes itself. On top of that, you get Envelope mode and the DRG — quite a lot of truly useful features.

In the end, the ultimate test of a piece of gear is, will I buy one? I already own six compressors; do I really want this one too? Yes, without a doubt.

Rick DiFonzois a guitarist, composer, producer, engineer, programmer, and father. He has played with Bob Dylan, Mick Jagger, and Roger Waters, among others. Like other guitarists, he always needs something to whine about.

Triple-C Specifications Digital I/O(2) S/PDIFAnalog Inputs(2) balanced ¼" TRSAnalog Outputs(2) balanced ¼" TRSAdditional PortsMIDI In, Out, Thru; (1) ¼" TS footpedalSampling Rates44.1, 48 kHzOutput Dither24-, 20-, 16-, 8-bitD/A Conversion24-bit, 128× oversamplingDisplay23-character, 280-icon
Super Twisted Nematic (STN) LCDOperating Level+4 dBuDynamic Range100 dB (20 Hz-20 kHz; analog input)Total Harmonic Distortion0.002% (@1 kHz, +20 dBu; analog output)Frequency Response20 Hz-20 kHz (+0/-0.5 dB @48 kHz; analog output)RAM/ROM Programs100/50Dimensions1U × 8.2" (D)Weight4.1 lb.


TC Electronic
rackmount digital compressor
$699 (mono model)
$999 (stereo model)



PROS: Flexible compression modes. Smooth sound when you want it. Nice tube simulation. Extremely fast attack times. Eye-catching, information-packed display. Good MIDI implementation. 100 user programs. Moderate price.

CONS: Look Ahead and Peak functions unavailable in Full-range mode. Difficult-to-read front-panel graphics. Mediocre manual.


TC Electronic
tel. (805) 373-1828