SPL Frontliner Recording Channel Strip W/ A/D Converter

With the finest ingredients from SPL, the new flagship of SPL's channel strips establishes the basis for world-class recordings – and each of its particular processing stages can be inserted into studio environments or DAWs like analog plug-ins! The brand-new Frontliner has all tools on board to record vocals and instruments in perfect quality: it merges a preamp, a de-esser, an EQ and a compressor.

Thanks to it's individual analog I/Os, all these powerful, hi-end analog processors can be inserted into any studio by the Frontliner pilot, i. e. to use them also during mixing and mastering. Thus it appears that the Frontliner is not reduced to a frontend device – especially DAW based studios get the chance to integrate high-grade analog processing at any stage of the audio production process.

The modules
The hybrid preamp with discrete transistor stage and separate tube stage combines high performance and neutrality with the option for sound coloration by enhancing the harmonic content with the switchable tube drive. The unique one-knob de-esser employs a phase cancelling technique to reduce sibilants. With three bands, the EQ section covers the complete frequency spectrum efficiently, and a tube saturation control allows to apply distortion to any signal from subtle to reckless levels. The compressor offers all classic parameters and a controllable automation of attack and release which adjusts the setting of time constants to the input signal – pretty much like a cruise control.

Heritage
Now the Frontliner comprises the same discrete, hybrid semiconductor/tube preamplifier design like the GoldMikeMK2. The compressor module is based upon the Kultube providing a full set of classic controls. We also integrated the Kultube's highlight, a signal-dependent automation of attack and release parameters which can still be influenced manually – with this option, manual and automatic control can be merged to always find the best settings.

The EQ section provides two semi-parametric filters for low and mid band as well as a bell filter delivering a silky and smooth top end. This filter set offers a perfect frequency first aid kit and is rounded off with a Tube Saturation control.

In contrast to semiconductors, a tube does not clip from a certain level, but approaches its limits by increasingly producing harmonic distortions. The sound effects from saturating a tube can often be used to improve the audio signal. The sound results resemble tape saturation effects and increase the density and perceived energy in a very pleasant way.

The Frontliner concept
The task of a channel strip is relatively complex. There is not one specialized device for one job, but a unit that combines a lot of technology for the preamplification and processing of audio signals. That is why especially the Frontliner benefits very much from SPL’s innovations for targeted, efficient work. The SPL De-Esser, for example, performs a highly complex processing, but can simply be adjusted with one single knob. The straight and clear front panel design also supports fast and safe operation.

Analog plug-ins
In the last years we have been busy with modular concepts. One result is the RackPack series: a RackPack frame hosts up to eight 3U high modules for free placement and (inter-) connection.

But we have also transferred the modular idea to the Frontliner. Each Frontliner module disposes of its own inputs and outputs. Sophisticated switching options allow to integrate Frontliner’s modules into a studio environment as if they were stand-alone devices. You can also group modules in any combination and you can determine inserts at each module’s input.

If you imagine the Frontliner modules as analog plug-ins, the additional value suddenly becomes apparent: this channel strip also is a versatile analog processing station. With one single unit, especially DAW based studios benefit from a first-class recording front-end and have access to high end analog processors for the main signal processing tasks.

Like other converter-compatible SPL products, the Frontliner comes with an internal 24bit/96kHz analog to digtal converter module 1090.

Features

• Three separate, individually optimized inputs for microphones, line signals and instruments
• Discrete semiconductor/tube hybrid preamplifier to combine the advantages – high dynamic range and low noise operation of semiconductors with the musical qualities of tube sounds (appealing top end, beautiful spacial impression). Discrete construction is based upon single transistors instead of integrated circuits (ICs) from industrial production and ensures a higher level of optimization
• 250 volts tube circuits in the preamplifier and for tube saturation stages
• High-grade operational amplifiers from Burr-Brown at critical positions
• The SPL De-Esser applies the method of phase cancellation for reducing sibilants. This innovative approach works much more neutral than traditional compression methods – a unique method for unobtrusive results and extremely fast operation
• The compressor is operated by SPL’s double VCA drive circuitry. A differential stage eliminates side effects and the half load per VCA dramatically reduces THD
• The operational amplifiers for the compressor circuitry meet military specifications. Therefore the regulating voltages are extremely precise – a precondition for high signal processing quality
• Selected condensers for the EQ filters with pleasant sound characteristics. Especially with vocals, amplified frequencies are not sounding too bright, and on the other hand reductions can tame harsh sounds without sounding dull
• Central star ground wiring scheme minimizes influences that could affect the ground paths. The audio ground is separated from the ground of the remaining equipment. This leads, in the truest sense of the word ”clean”, to considerably improved tonal quality
• The power supply is built around two toroidal transformers, one for the audio voltages and one for the other supply voltages (tube heating, LEDs, micro controller etc.) Mutual interferences are excluded and lavishly over-dimensioned capacities ensure absolutely stable supplies for all audio circuitries

24Bit/192kHz AD Converter Module (1090)
The Analog/Digital Converter Module 1090 is a digital output for compatible GainStation 1 with a plug-and-play design for easy installation. It offers an S/P-DIF output with both coaxial and optical connectors in parallel. The heart of the module is a 24-bit converter with a variable sample rate of up to 192 kHz. Highly accurate quartz oscillators ensure a clean, low-jitter master clock.

The internal sample rate can be switched between 44.1, 48, 88.2 and 96 kHz. Other sample rates (32, 176,4 and 192 kHz are set by external syncronization. The converter can be synced to other digital devices via a S/P-DIF input. The internal oscillators are automatically disabled when an external clock signal is present to prevent interference.An extremely effective voltage stabilizing circuit ensures that the converter continuously receives sufficient and stable voltage – an important prerequisite for clean, transparent audio. The compact design of the input stage guarantees the shortest possible signal path to the converter. Over dimensioned grounding surfaces on both sides of the circuit board effectively reduce interference and ensure optimal separation between analog and digital components.