• Account
  • View Shopping Cart

Menu Search View Shopping Cart Call Us

Sebatron THORAX Valve Mic Pre and Compressor  From Sebatron

The Sebatron THORAX is an evolution from previous models, most notably in  Frequency response, dynamic range, and improvements over noise floor and compression characteristics. Quality components and build make this Valve Microphone preamp and Compressor a must for any professional recording setup!



Retail:  $2,200.00

"Experience the Difference"

Sound Pure's 3-Year Warranty

Our Free 3-Year Warranty!
In addition to the standard included manufacturer warranty, virtually all new products carry our exclusive, industry-leading, absolutely free, Sound Pure 3-Year Warranty, which includes PARTS & LABOR. This high-value perk is our way of providing the ultimate in added value to enhance the unique personal touch our small, dedicated team contributes to each purchase.
Learn more »

Lifetime Support

Free Lifetime Technical Support!
Our small team of dedicated experts is here to help the original purchaser for the lifetime of the product. Why? Because we care about building real relationships with our customers for life and stand behind every product we sell.

Free Shipping

This Product Ships Free!
Products ship from our well-located, climate- and humidity-controlled warehouse absolutely free (inside the continental USA). Low-cost international shipping options exist for most products.
Contact us for details »
Contact us for up-to-date delivery estimate.
Payments as low as $43/mo.

Manufacturer's Description from Sebatron

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.


Thorax preamp:

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.

Thorax compressor:

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.


About Manufacturer

Unique high-quality organic valve and class-A solid state studio equipment. No integrated circuits. Made in Australia.


Valve Type: 12AT7 or ECC81 ( two valves required )

Prefered Valve Brand(s): J.J, Amperax, Telefunken, JAN

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

Maximum Input level ( mic ): +4db

Maximum Input Level (D.I ): +10db

Maximum Output Level: +30dbm balanced

Total Gain of preamp section: 68 db

Additional Compression makeup gain: 30db

Input Impedance (mic): 1K ohm

Input Impedance (D.I): 100K ohm

Output Impedance: Less than 600 ohm

Min Compression Attack Time: 1ms

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

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

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


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

Build: Chassis is 1.2mm mild steel powder coated ‘Textured Black’

Front Panel: 3mm mild steel powder coated ‘Magnolia’

Modular P.C.B: Preamp for easy servicing and modifications

Topology: Discrete and Class A Valve and Solid State signal path running on +300V and +60V rails respectively

Circuitry: Class A Discrete and low noise

Two Dual Triode 12AT7/ecc81 and High Voltage Silicon Transistors





Thorax Manual