COMPTROLLER

NOT JUST ANOTHER COMPRESSOR

The Comptroller is a completely new and unique circuit designed for extreme transient manipulation. It’s wild, complex and a bit unwieldy until you get used to it. It's difficult to describe because it simply doesn't sound or behave like anything else available. It combines a VCA compressor with an ultra fast JFET peak limiter. The compressor has a specially designed detector circuit that mangles the transient response in extraordinary ways.

The Contour control is the key to what sets this unit apart. In technical terms it slows down the compressor response and makes it slightly unstable. The practical effect is that transient changes cause the compressor to overreact, creating a brief drop in volume before returning to a normal compressed level. In Figure 1 you can see the response to a simple tone burst. The top waveform is the input, middle is regular compression, and bottom is with Contour engaged. The audible effect this produces is quite unusual and compelling. With fast settings it enhances the impact and punchiness of transients in a really magical way. Slower settings can completely change the rhythmic feel.

Figure 1: Compression Curves

DYNAMIC CONTROL

The control set has been carefully designed to offer a broad range of distinct sounds. Input Gain, Attack, Release and Contour are all on 6 position rotary switches. The rest of the controls are on standard potentiometers. Timing can be adjusted for fast transient snap or slow pumping. Depth ranges from gentle enhancement to severe gating. It sounds cooler the more you push it, so 25dB of available input gain gives you the ability to destroy the signal. And unlike a traditional compressor, the Contour effect allows you to crush drums and still retain the impact of transients.

The compressor section is followed by a super fast JFET based peak limiter. This is a true peak limiter that reacts instantly with zero recovery time. Three limiting modes give you varying levels of control over the response. Soft is a gentle saturation, Medium adds some feedback, and Hard mode is brickwall clipping. The Contour effect can easily generate extremely high level transients while severely attenuating the signal in between. The peak limiter was added primarily to control the transients while maintaining the reactive nature of the Contour response.

FLEXIBILITY

This unit can operate in either Stereo or Mono mode. The compression detector sums the left and right channels and applies the same control voltage to both. In Mono mode only the left channel is driving compression, but the right channel is still being affected. This allows for some very creative ducking effects. There are several other options for modifying the detector signal. The Post Pk Lim switch puts the output of the peak limiter into the control loop, which can dramatically change the compressor response. The external sidechain loop lets you apply EQ or other processing to the detector signal. External Key puts a separate VCA into the sidechain signal path so you can trigger compression from an external source. The 500Hz low pass filters out ambient high frequency information, further enhancing the impact of low frequency transients. The Peak Limiter has individual detector circuits for each channel that are controlled by a single threshold voltage. Instead of a traditional meter, single LEDs indicate when compression and peak limiting are active.

The Comptroller is my first non-customizable "retail" product. I assemble all of them by hand in small batches to ensure the highest quality. I maintain a low overhead and by selling direct I am able to avoid the extra cost incurred by going through a retailer.

SPECIFICATIONS

• Maximum Output Level: +25 dBu (0.1% THD)
• Input Gain: +25 dB in 5 dB Increments
• THD + Noise: -80 dBu (10Hz - 80kHz Un-weighted)
• Frequency Response: +/- 0.1dB 10Hz-63kHz
• I/O: Electronically Balanced DC Coupled
• Power: 120/240VAC 50/60Hz (Switchable) 16 Watts Max

COMPTROLLER USER MANUAL