With the Portico II Channel, every possible attention has been paid towards producing the most accurate, sweet-sounding audio topologies.
The Portico II Channel was created using the high voltage topologies from the 5088 to create a channel strip with the ultimate sound quality. Comprised of a fully-featured mic preamplifier, 4-band EQ, compressor-limiter, "texture" control and level metering, the Portico II Channel includes a bevy of new features including; Variable Silk with Texture control, a fully tunable "de-esser", multiple VCA filtering and detection options, a transient-optimized swept HPF and parallel compression blending. With its simple yet powerful topologies and extensive feature set, every element of the Portico II: Channel is geared towards empowering recording artists to realize these visions.
Input signals may be derived from any of three sources; Microphone, Line or DI. The Microphone input has a 10K Ohm non-reactive input resistance that handles a full 26dBu signal without the need for a pad. A primary Gain control provides 66dB of gain in 6dB increments for easy recall with a +/- 6dB Trim for fine adjustment. A transient-optimized HPF variable from 20-250Hz is included. Additionally, a 48V Phantom Power switch, Phase Inversion, Signal Present indicator and a Mute switch are included. The pre-amp is a TLA non-reactive design that precludes the loading of microphones with limited driving capability and which maintains a 2 dB noise figure over a wide range.
Inserting a plug into the DI input selects a 3M Ohm discrete FET DI circuit with a transformer-coupled topography that optimizes both the microphone and DI inputs, allowing low impedance microphones and high impedance sources like electric guitars and basses to sound their very best. Primary Gain and Trim controls are fully operational. A "Thru" jack on the front panel that duplicates the unaffected source signal allows the use of an external amplifier if required. A "Line" switch selects the independent Line XLR non-reactive input circuit that includes the HPF and Level Trim controls.
One of the key developments in the Portico II Channel is the new Texture section. Building on the "Silk" mode found in the original Portico Series mic preamplifiers, Texture is designed to adjust the actual amount of musical harmonic content from the source material - in effect, providing countless tonal options in one device. The texture section can vary from barely audible to dramatic, all controlled by a single knob. With that said, we have taken great care to ensure that the musical integrity of source material itself will not be compromised by these harmonic controls - these are not to be confused with controls from other manufactures that may "incinerate", "demolish" or "destroy" source material - and we believe they can be confidently used to fit the personality of any song, instrument or engineer.
As with the original Portico modules, the blue Silk mode works by reducing negative feedback on the output transformer and adjusting the frequency response to more closely resemble Mr. Rupert Neve's vintage designs. This blue mode tends to affect harmonics generated by the source material's low and low-mid frequencies, filling the sound out from the bottom up. The red "Silk +" mode provides a different level of control, enhancing harmonics generated by the source material's high-mid and high frequencies, adding a harmonic "sparkle" to your original signal.
The EQ topologies in the 4-Band Equalizer of the Portico II combine the best-loved sound of several classic designs, but are also capable of extremely fine surgical adjustments as well as dramatic boosts or cuts. By default, the EQ section follows the mic preamplifier and HPF and precedes the compressor, but this sequence may be reversed by engaging the Post Comp switch.
The Low Shelf has an independent engage switch, Classic Peak / Accelerated Shelf selection, with +/- 12dB level adjustment, and selectable turnover frequencies of 35, 60, 100, and 220 Hz. The Fully Parametric LMF and HMF bands have a joint engage switch, providing +/- 12dB level adjustment, continuously variable "Q" from 0.7 to 5 and continuously variable frequency ranges from 70 to 1.4kHz and 700Hz to 14kHz. In addition to its standard capabilities, the HMF band can also be used to precisely tune the new De-Esser circuit.
The De-Esser can be varied from off to full effect, and uses the Frequency and "Q" controls to tame harsh sibilance in vocals and instruments with an independent high-mid limiter. Even when the De-Esser is on, the EQ level may still be used. The High Frequency shelf has independent engage switch, Classic Peak / Accelerated Shelf selection, +/- 12dB level adjustment, and selectable turnover frequencies of 4.7, 6.8, 12, and 25kHz. When two Portico II Channels are used side by side, the EQ section can also excel at stereo material.
A further array of tools are used to craft dynamic response. The Portico II's compressor section is exceptionally flexible. Like the Portico 5043, the VCA compressor has a choice of Feed-Forward / Feed-Back modes, either providing a transparent modern response (FF) or a smoother, more vintage response (FB). Along with FF/FB modes, there are also 1:1 to 40:1 ratio controls and threshold from -30dBu to +20dBu, together with Attack from 20 to 75ms (.1 ms in Peak mode), Release from 100ms to 2.5s, and Make-Up Gain from 0 to 20dB. A link switch is provided to link the compressor action with that of an additional connected
The Portico II compressor incorporates a number of new ways to tame and enhance dynamics. "HPF to SC" inserts the High Pass Filter into the side chain to deal with intense low frequencies that may skew the response of the VCA with certain songs and instruments. The "Peak" switch alters the compressor's attack to react to transients with a roughly .1ms response time. When "peak" is disengaged, the compressor responds to the RMS signal in conjunction with the attack and release settings.
"Blend" works by creating a parallel mix between the compressed and dry signals. By mixing the compressed and dry signals, it is possible to increase the volume of quieter elements in the source material (for instance, delicate snare brushing on a track with much louder hits), while maintaining a natural dynamic feel for the louder elements.
To further control the side chain, there is also an insert "send" and "return" that may be paired with an external EQ or other filters for additional manipulation. The "return" may also be used as a "Key" input for ducking one signal under another. (for instance, a voice-over keying the compressor to duck a background music track). By connecting the "link" jack on the back of the Portico II to another Portico II link jack and engaging the Link buttons, the compressor section may be used for stereo material.
Continuously variable control for Silk and Silk+ modes allows the engineer to fine tune the harmonic ratio and tonality of the channel.
Moves the EQ after the Compressor
Tunable with the HMF EQ bandwidth reduction, the multi-variable De-Esser can be used to soften harsh sibilance in voices and instruments
A parallel matrix providing continuously variable control to mix compressed and uncompressed signals
Changes the VCA Detection from a forward feed design (fast, more accurate attack & release) to a feed back design (smoother, more musical response)
RMS / Peak
Overrides the attack setting, using a combination of peak and RMS detection set below 1ms
Side Chain Send/Return
External compressor side chain send and return on 2 x TRS jacks. The send is always active and normalled to the return (NOTE: If the send and return are connected to a patchbay, the send should be normalled or connected to the return by default, as the compressor will not trigger if the return has no signal)
Dual 16 point peak meters display compressor (not de-esser) gain reduction and output levels
High Pass Filter
Continuously variable from 20-250Hz
HPF to Side Chain
Uses the HPF in the Compressor Side Chain
Provides 66dB in 6dB steps
Continuous +/- 6dB level contro
Reverses the polarity of the signal
Selectable 48V for powering microphones
Discrete FET input for Hi-Z instruments
Selectable +4 balanced input
+/-15dB adjustment at 35, 60, 100, and 220 Hz, independent LF engage, selectable classic bell or accelerated shelf curves
+/-15dB adjustment from 70 to 1.4KHz, with a continuous "Q" from .7 to 5., engaged with the MF switch.
+/-15dB adjustment from 700Hz to 14KHz, with a continuous "Q" from .7 to 5., engaged with the MF switch.
+/-15dB adjustment at 4.7, 6.8, 12, and 25kHz, independent HF engage, selectable classic bell or accelerated shelf curves
All EQ In
Enables all EQ Bands (Individual bands must still be engaged)
Engages Compressor section
Main Output, no load
-3 dB @ 2 Hz
-3 dB @ 160 kHz
Measured at Main Output, unweighted, 22Hz-22kHz,
Terminated 150 Ohms.
With gain at unity better than -92 dBu
With gain at 66 dB better than -56 dBu
Equivalent Input Noise better than -123 dBu
Unity to +66dB in 6 dB steps,
Trim continuously adjustable from -6dB to +6dB
Trim continuously adjustable from -6dB to +6dB
Maximum Output Level:
Maximum output from 20 Hz to 40 kHz is +25 dBu.
48 Volts DC +/- 1%
Total Harmonic Distortion and Noise:
@ 1kHz, +20 dBu output: Better than 0.002%
As above, Silk Engaged: Better than 0.2% Second Harmonic
@ 20Hz, +20 dBu out Better than 0.004%
@ 20Hz, +20 dBu out Better than 0.020%
IM Distortion: Better than 0.002%
Slew rate Better than 4 V/uS
High Pass Filter:
Frequency: Continuously Variable from 20 Hz to 250Hz
Slope: 12 dB/Octave Bessel