The new Dual Engine Compressor Limiter is based on the Opti-FET Compressor design, and it shares many of the same qualities with a few notable differences. The compressor circuit used for the new design is the same as the one currently used in the Opti-FET compressor, so the new pedal will provide the same compression characteristics which has made the Opti-FET our most popular compressor to date. The threshold, ratio, and attack settings on the compression side of the new pedal will also match the specifications of the current Opti-FET design. Like the Opti-FET, the Dual Engine Compressor Limiter is an optical compressor design.
Now that we've identified the main similarities between the new Dual Engine Compressor Limiter and the current Opti-FET Compressor, let's take a look at the differences in the new design...
Where's the release control?
As you may have noticed in the drawing above, the new Dual Engine Compressor Limiter pedal is lacking the release adjustment control. The Dual Engine Compressor Limiter utilizes an adaptive release design which is similar to those found in several rack mount compressor units, often identified as a program dependent release or PDR. The adaptive release behaves similar to the natural response of the human ear as it automatically adjusts to sound pressure levels and background sound over different periods of time.
In essence, the way the adaptive release works is that the longer the input signal consistently crosses the threshold, the longer the release time will become. The incremental time period for the release adjustment is set between 0 and 5 seconds for the compressor, and between 0 and 2.5 seconds for the limiter. The release time range (release setting) for the compressor is 100mS to 600mS, and for the limiter it is set between 20mS to 250mS. As an example, if a quick succession of staccato notes are played, then the release is fairly quick, and if long drone notes are played, then the release will be slower. The release times are automatically adjusted up or down as the input signal consistently remains above or below the threshold setting.
For those that don't want the adaptive release control, there will be internal DIP switches for both the compressor and limiter that will disable the adaptive release feature. Disabling the adaptive release for either the compressor or limiter will set the release to its fastest setting respectively.
The new Dual Engine Compressor Limiter features a selectable and adjustable limiter which operates along with the compressor when active. It includes independent external controls for threshold, attack, and gain as well as adaptive release functionality. The attack and adaptive release ranges for the limiter have been designed with parameters that are optimized for limiter functionality. The limiter has two LEDs which are used to show when the limiter is engaged and when the input signal crosses the limiter threshold setting.
The warmth control provides a way to add harmonics to the signal from within the final output stage amplifier in the compressor. The range of the warmth control is from very clear and transparent at the minimum setting to thick and warm tone at the maximum setting. The ability to warm up your signal provides the musician with a way to add some of that "old school" compressor feel and tone.