GC Audio Inherit Rack Graham Langley Cartridge

Overview by Graham Langley
“When I first discovered the GC Audio “Inherit” system I was impressed by the innovative concept of interchangeable microphone amplifier cartridges allowing customers the flexibility and freedom of choice to enhance their creativity.

The thought that had gone into the design and the build quality of the product also appealed to me.

I was therefore honoured when invited to contribute a “Langley” microphone amplifier cartridge design.

I designed a custom preamp to completely match the capabilities of the Inherit System.

The circuit is reminiscent of the topology that I used in Amek console microphone amplifier designs in the 1970s and 80s but with significant improvements, particularly in noise performance.

This cartridge is intended to provide a clean, transparent sound over the full audio frequency
spectrum.

I hope you enjoy using this addition to your “Inherit” cartridge collection.

Specifications
- PAD : -20dB
- Input impedance: 5K Ohms
- EIN (150 Ohms source @ 60dB, 22hz/22Khz) : better than -127dB
- THD + N: 0.04%
- Gain command Grayhill commutator of 12 steps 1) 16 dB, 2) 20 dB, 3) 24 dB,  4) 28 dB, 5) 32 dB, 6) 36 dB, 7) 40 dB, 8) 44 dB, 9) 48 dB, 10) 52 dB, 11) 56 dB, 12) 60 dB (+/-1dB)
- Output level via linear potentiometer
- VU meter LED 10 Segments, factory calibrated at 0db Vu = +4dBu with PRE/POST switch
- Pre/Post switch of the LED indicator for the output level potentiometer to achieve very high gain without saturation of the converter
- Low cut: 80 Hz - 120 Hz - Slope: 12dB / octave
- 7 internal linear DC power supplies with very low noise
- PAD: -20dB
- Phantom power supply +48V
- Phase inversion
- DI input impedance: 500K ohms

Modular systems already exist, so why the Inherit system?
Modular systems like the 500 are imperfect and like all versatile systems, they do not excel in any one area and are therefore not the ultimate solution for solid state or tube amplification for the ultimate sound seeker. The function of preamps is to process weak signals, so they are very sensitive to electromagnetic interference and require shielding that the foramt 500 cannot provide.

Moreover, the shielding of racks and lunchboxes 500 is not always of very good quality. The Inherit system offers a high quality multiple power supply and an excellent shielding environment.

The concept
The idea behind the Inherit system is to offer an uncompromising mic/instrument preamp, incorporating exceptional components and offering a modular amplification expert. A preamp is the main element for a good sound recording. In an audio chain, it is placed just before the digital conversion. It is therefore by definition analog and not transformable.

Contrary to other modular formats, it allows the implementation of high voltage or high current multi-voltage preamplification technologies. In addition, the lack of space constraints and the improved EMC (electromagnetic compatibility) environment allow for fewer compromises in electronic designs. The result is exceptional audio quality. The preamps available through the Inherit system are simply not available in the 500 format, due to its limitations.

Isolation
The proprietary Inherit format keeps the sensitive part of the electronic design in a one-piece machined cartridge that acts as a Faraday cage to offer optimal electromagnetic shielding performance. and the design allows great convenience for the user is very practical.

Uncompromising sound quality
This is a premium recording preamp for professionals and sound engineers looking for uncompromising results. But although it is primarily dedicated to recording studios, its rugged construction allows for extensive use on tour for FOH engineers who want to use different sound colors without the hassle of carrying multiple racks.

Exclusive characters
When recording, users can quickly and easily compare, for example, the sharpness of a Solid State mic pre with the warmth of a real tube preamp, without having to patch. Some cartridges are designed around proven technologies that are standard in recording studios and others are designed around new, exclusive technologies specific to the Inherit system. The Inherit system will therefore allow you to access complex preamplifiers such as true tube preamplifiers or complex discrete designs that are impossible to obtain with a 500 Series modules.

The Rack
All functions of the Inherit rack are analog, digitally controlled in a highly shielded construction to protect the signal path. This allows each cartridge to retain its unique and unaltered sound.

As for the proven technologies, many improvements have been made to achieve a high signal-to-noise ratio while maintaining the original exceptional behavior and tonal color that made them classics.

The power supply
The rack's custom power supply was designed with great care and contains 7 unique voltages that are generated by three toroidal power transformers.

Frequency VS gain

THD + N

Phase