Mercury-1 is an analog-modeled, monophonic, VST plug-in instrument. Its synthesis architecture (dual oscillators as well as a suboscillator, a resonant

Mercury-1 is an analog-modeled, monophonic, VST plug-in instrument. Its synthesis architecture (dual oscillators as well as a suboscillator, a resonant lowpass filter, dual ADSR envelopes, and an LFO with a choice of waveforms) holds few surprises. Nonetheless, its sound can shake the walls, break the windows, and unilaterally declare World War III. Its four voices cannot be played simultaneously on a single MIDI channel, but they can be layered, split, or sequenced independently using separate MIDI channels. Mercury-1 is easy to program, and with support from your host program, its front panel can be automated through MIDI.

The front panel displays the settings for the active voice (see Fig. 1). Across the top, four Voice Tabs let you select the active voice, which is indicated by a silver tab. Each voice has its own MIDI channel, key range, Velocity range, and VST audio-output channel, and each of the voice parameters can be set by the user. (It's nearly impossible to find the sweet spot for scrolling the Output numerical, but you can double-click on the number to type in a value.)

Mercury-1 processes notes with high-note priority and without retriggering; if you hold one note and play a note below it, the lower note won't sound. If you hold a note and play a note above it, the pitch will change to the higher note, but the envelopes won't retrigger. That arrangement lets you play trills like you can on a Minimoog.


Mercury-1's latency and demand on your CPU depends on your platform, sound card, and audio drivers. On my Macintosh G3/300 with an Emagic Audiowerk8 sound card, Mercury-1 was quite playable using Emagic's Logic Audio 4.7 and Steinberg's Cubase VST/24 4.1. For many VST plug-ins, your choice of host applications doesn't make much difference, but it does affect Mercury-1's feature set. To see why, here's a quick look at how Mercury-1 manages its four voices.

Logic Audio doesn't support multiple VST audio outputs for single instances of a VST plug-in, so you can't apply different effects to Mercury-1's four voices. However, you can use Logic's Environment to distribute MIDI note messages across several MIDI channels and simulate last-note priority with retriggering; that lets you play Mercury-1 in real time with four-note polyphony.

Cubase supports independent processing of each Mercury-1 audio output, letting you apply separate effects to each voice. That is extremely nice for sound-effects design. For example, you can put a delay after some voices to control their timing in the overall sound effect. On the other hand, you're stuck with monophonic real-time performance; you can play polyphonically only by multitracking separate MIDI channels.


Mercury-1's signal path starts with two analog-modeled oscillators. Osc 1 offers sine, sawtooth, and square waveforms as well as white noise. Osc 2 offers square, sawtooth, triangle, and variable-width pulse waveforms. Each oscillator can be octave-shifted, and Osc 2 can be detuned in cents or semitones. The Sub slider in the Mixer section adds a square wave an octave below Osc 1.

Osc 2 can be hard-synched to Osc 1 by clicking on the Sync button. You can also route the two oscillators through a ring modulator by clicking on the Ring button. When ring modulation is on, the Mixer's Osc 2 slider controls the level of the ring-modulated signal, and the Osc 1 slider controls Osc 1; that is equivalent to amplitude modulation of Osc 1 by Osc 2.

The Xylophone program uses that technique; with a little tweaking of the detune and envelope parameters, you can create viable marimbas, steel drums, and other one-hand mallet instruments. When either hard sync or ring modulation is on, pitch-modulation routings affect only Osc 2. Modulating only Osc 2's pitch in that manner is an excellent way to program classic synth-vocal sounds, such as 303 Wow, and clangorous bell-like sounds, such as High Bells.

Mercury-1's 4-pole resonant lowpass filter has a nice, fat sound. It won't oscillate on its own, but a little push will get it going; the Sonar program demonstrates that effect quite well. According to the manual, the amplifier's Drive slider adds TC Works' “renowned SoftSat analog-overdrive emulation.” Whatever you call it, the overdrive is gritty and effective, but as you'd expect, you have to be prepared to ride the Volume slider.

Mercury-1's modulation options are adequate if not extensive. There are two ADSR envelope generators (EGs). Env 1 can be applied either straight or inverted to modulate the pitch of both oscillators, Osc 2's pulse width, or filter cutoff. Env 2 can be applied to the amplifier or filter cutoff. In case you want to use Env 2 exclusively for the filter, the amplifier has a Gate mode. The LFO's ability to trigger Env 2, as demonstrated by the Filter Seq Line program, is a welcome feature. It would be nice if the LFO could also trigger Env 1.

The LFO offers sine, ramp-down, and square waveforms as well as sample and hold; it can be routed to pitch, pulse width, and filter cutoff. Its Delay control is a fade-in ramp, which is great for some effects but not so good for others. The LFO offers both Key Trigger and MIDI Sync. I discovered a bug that at times makes it necessary to temporarily turn on Key Triggering to enable the LFO.

A hierarchical menu is used to route MIDI Velocity, Modulation, and Aftertouch (see Fig. 2). Velocity has the most extensive set of possible destinations. The Modulation options are a little skimpy; strangely, there's no way to route Modulation to change the LFO rate.


Mercury-1 comes with a bank of 128 factory programs divided into seven categories: sound effects (FX), basses (BA), classic synths (SY), lead synths (SL), sequences (SQ), brass (BR), and drums (DR). Most Programs are in the bass, synth, and sound-effects categories; those are the sounds that Mercury-1 does best.

Many of the synth sounds fall into the everything-you-can-do-to-an-oscillator-and-filter-with-an-envelope-and-LFO classification, but there are also some useful emulations. The Flute, Theremin, Xylophone, and Harpsichord are especially playable, though the last two lose something by being monophonic.

Names like Electronic Woodpecker and Marscape give you a clear idea of the sound-effects lineup. The program's real power comes from being able to layer sounds while processing them separately with other VST effects.

The basses run from punchy Moog-style to thinner ARP- or Oberheim-style; percussive basses and bass effects are also present. Analog-overdrive emulation, crisp envelopes, and the ability to layer voices provide various solid bass sounds.


Mercury-1's factory program bank is permanent; it's restored each time you invoke Mercury-1 as a VST plug-in. Consequently, changes to the program bank are lost when you remove an instance of Mercury-1. They're also lost each time a Logic song is closed. To permanently store a program or bank, which includes the configuration of all four Mercury-1 voices (called a Multi), you must rely on the host application's built-in memory management.

The easiest way to audition Mercury-1 programs is to use the Program Manager, which you open by clicking on the Prog button in the middle of the control panel. In Compare mode you can audition programs by selecting them from the scrolling Program Browser.

Use the Program Manager's Load and Save buttons to open and store programs for the selected voice. Conveniently, you can also double-click on a program name in the Program Browser to load it into the active voice. The Program Browser's Copy button copies the selected program into its clipboard, and the Paste button pastes the clipboard's contents into the selected location in the Browser. Those buttons let you move programs in the Browser without affecting any Mercury-1 voice.

The Program Manager's one awkward aspect is its automatic selection of the last program loaded rather than the one in the active voice. If you change a voice's settings and then open the Program Manager to save your work, you may need to scroll around to find the location of the Program you're trying to save.


Mercury-1 is fun to play and easy to program. Its strong points are basses, leads, and sound effects. Its monophonic, multitimbral architecture is slightly limiting, but the ability to layer voices produces fat eight-oscillator-plus-four-suboscillator sounds and effects.

Considering the number and variety of VST synth plug-ins, Mercury-1 doesn't offer a lot of bang for the buck, but it has its niche. Download the fully functional, seven-day demo from TC Works' Web site. Mercury-1 is at least worth a test-drive.

Minimum System Requirements


MAC: G3/233; 64 MB RAM (128 MB for OS 9.0 or higher); OS 8.6 or higher; VST-instrument — compatible host program

PC: Pentium II/200; 64 MB RAM; Windows 95/98/2000/NT 4; VST-instrument — compatible host program


TC Works
Mercury-1 (Mac/Win)
VST synthesizer plug-in



PROS: Powerful lead and bass sounds. Versatile sound effects. Familiar, easy-to-program, analog-style interface.

CONS: Monophonic with high-note priority only. Program-management scheme is cumbersome.


TC Works
tel. (805) 373-1828