THORAX - Pre/EQ/Comp

The New Sebatron THORAX features a two band passive EQ and optical compression with detailed parameters.

There are numerous advantages to housing preamp/EQ and compressor under the same lid.
Most notably is the fact that buffer circuitry (which is used to enable core circuits to drive long cables) can be minmized or eliminated. This contributes to a streamlined audio path. Additionally, processing sections can be incorporated into the gain stages themselves further streamlining the audio path.
The new Thorax has both these benefits which contribute to a low noise floor and wide bandwidth.
The added advantage of High Voltage rails and discrete Class A circuitry make the Thorax deal with audio signals with a huge amount of headroom and minimal sound degredation.

The Thorax preamp features six way selectors for pad/gain and shelf EQ. This allows for quick recallable settings and improved performance.
Both High and Low shelf EQ have been intergrated into the preamp circuit to preserve signal purity.
The frequency bands chosen are the ones which resonate best with this configuration.
The High shelf EQ is smooth and never brittle and can be used to open up signals for increased clarity and definition.
The Low shelf EQ adds or subtracts low frequency response to the signal and can be subtle or obese depending on the setting.
The Equalizer sounds natural and classic leaving surgical manipulations to be done in the box.

Adjusting the pad/gain selector not only changes the amount of amplification of the preamp but changes response and colour.
The ranges overlap so there is more than one way to get to the gain required with a different response.

Loosely based on our SMAC optical compressor, the Thorax compressor section has been designed for
vesatility and ease of use. Sounds can be compressed from different angles to achieve the required result.
To squash sounds even further the Thorax is equipt with a pump setting that extends ratio control and in feedforward mode creates a slight duck.
The two compression curves, feedforward and feedback, have different processing charactersitics most obvious at higher ratios. Each one applicable to a certain situation and easy to set up.
Another valuable feature is the comp mix control which can allow one to retain some of the dynamics of the original signal.


Maximum gain (mic input) : +68 db

Maximum gain (direct input) : +62 db

Maximum input (mic input) : +10 dbu

Maximum input (direct input) : +16 dbu

Maximum output : +30 dbu balanced

Frequency Response : 20Hz - 80 KHz +/- 2db (air 1)COMPRESSOR SPECIFICATIONS

Minimum Attack Time : 1ms

Maximum Attack Time : 25ms-tight 1sec-swim

Mimimum Release Time : 4ms-tight 50ms-swim

Maximum Release Time : 2 sec-tight 6 sec-swim

Makeup Gain : approx 30db

Maximum Output : +30dbm balanced

Frequency Response : 20Hz - 80 KHz +/- 2dbOTHER SPECIFICATIONS

Dimensions : 482mm x 190mm x 88m

Power : Externally switchable 110/120/220/240 VAC for global useage.

Build : Chassis is 1.2mm mild steel powder coated 'Textured Black'. Front Panel is 2.5mm mild steel powder coated 'Transformer Grey'.

Topology : Topology is all discrete and Class A Valve and Solid State signal path running on +300V and +60V rails respectively.

Circuitry : Class A Discrete and low noise. Dual Triode 12AT7/ecc81 and High Voltage Silicon Transistors.