The GC Audio Analog Riser is a high-end dynamics and harmonics processor, which allows you to obtain sharp and unique dynamics and harmonics processing. It offers a unique sound signature for demanding engineers, right up to the mastering stage.
 
The Analog Riser is a fully analog design built around 5 tubes, 4 VCAs, 4 Lundhal transformers, a hundred low noise operational amplifiers, Grayhill switches, IP knobs, etc. Its powerful combinations of harmonic processing / make up and MS mode make it a unique machine.
 
No signal goes through the front panel switches. About 40 relays ensure a routing as close as possible to the motherboard. Each functions is trimmed in factory in order to have the best matching between left and right.
 
The Modes
Dual Mono Mode
Configuration A - All stages are active.
- This is the default mode when you power on the. An analog processor with two completely independent channels. In this mode, you can simultaneously process two tracks independently. As the device has many functions, it is necessary to understand its routing, which prioritizes dynamic processing above all. When all stages are on, the machine offers the following functions in order from top to bottom: Multi-band sidechain stage with LPF and HPF > VCA compressor > Harmonic > Tube > Limiter
Configuration B: When all stages are active but the Compressor stage
 
Stereo Mode
- This mode is dedicated to stereo BUS compression. The BUS compression being generally positioned on moderate ratios, it has been chosen a L+R summation for the Sidechain input. The limiter works on a ratio of +Infinite, it has no summation on the sidechain input in order to keep a faithful stereo image. A common Threshold, calibrated from factory, allows a precise adjustment between L and R. Also a Link of the VCA time control allows an identical behavior. In this mode, all control knobs are linked to obtain a very precise and identical adjustment between Left and Right. An "Active zone area" LED allows you to define the zones whose knobs are functional. Although the potentiometers are linked, the functions of both channels work and to activate a function, it is therefore necessary to switch it on the left channel and on the right channel. 
Configuration A - When all stages are active
In this configuration, it is sufficient to deactivate the compressor for monitoring the sidechain contour. In stereo mode, it is not possible to have a stereo equalizer, this one being exclusively dedicated to the stereo compression contour.
 
M/S Mode (Mid/Side)
- This mode dedicated to mastering is a very powerful tool that allows a different dynamic treatment between what is mixed in the center (Mid) and what is mixed on the sides (Side).
The M/S encoder and decoder are built around dedicated differential amplifiers with laser-etched calibration, allowing for the most precise signal processing. This mode is completely analog.
Configuration A - All stages activated.
The left channel controls the signal in the middle, and the right channel controls the signal on the sides.
Configuration B  - All stages are active but the Compressor stage.
The M/S function of the Analog Riser is very powerful. It allows new settings where it will be possible for example to make-up the tube gain on the sides and a discreet make-up on the middle.
 
The Stages
Equalizer Stage
- High pass 12 dB / octave, 20hz to 300hz.
- Low pass 12 dB / octave, 250hz to 20khz.
- Low frequency 20hz to 500hz, gain -12dB to + 12dB, variable Q.
- Medium frequency 300hz to 6khz, gain -12dB to + 12dB, variable Q.
- High frequency 5khz to 20khz, gain -12dB to + 12dB, variable Q.
Although the primary function of this EQ is to define a multiband contour for the compressor detection threshold, it can also be used as a stand-alone EQ. In Sidechain mode (compressor stage on), it has a narrow bandwidth for optimal VCA stability. The use of the equalizer in insert in the compressor sidechain allows  very precise dynmic treatments. To avoid a compression "pumping", a Low Cut is often used in the Sidechain to discriminate for example, the bass drum. With the multiband contour you can first find the exact frequency of the bass drum and only separate this frequency at the level of the compressor's release threshold. In the opposite case, you can turn up the gain only on the bass drum frequency which will give you a stable pumping with a good rhythmic behavior. 
 
Compressor Stage
- Threshold -30dB to +10dB
- Ratio 12 steps, 1.5 to 10.
- Attack 0.5ms to 300ms.
- Release 1.5ms to 1.5s
- Make up -20dB to +20dB
- Knee setting (Soft / Hard)
- Auto creator setting (automatic fast Attack and Release for transcient).
This compressor is built around a state-of-the-art VCA and features full adjustment of the Time, Threshold and Make Up components. With impeccable characteristics of signal to noise ratio and distortion, it is particularly stable. It is equipped with a new and original function, "Auto Creator". where the Attack and Release are automatic. They will be globally fast but vary with the speed of the input signal. The times will be different depending on the nature of the signal: transient or constant signal.
 
Harmonic Stage
- Harmonic generator
- Harmonic mix density
This stage generates odd harmonics. You can define the amount of harmonics generated as well as the density integrated in the original signal. The electronic design has been optimized so this function adds a proximity presence to the signal.
 
Tube Stage
- Gain 0dB to 20 dB.
- 4 stages of 12AY7 tubes on each channel.
- High voltage power supply with EZ81 bridge.
Each channel consists of four 12AY7 lamp stages. A high voltage EZ81 tube power supply offers a high quality choke filtering system allowing a very low residual ripple. The lamp power supply allows for a gradual rise in high voltage, preserving the life of the lamps. The unit allows two types of make up: The discrete make up of the compressor stage which has a transparent rendering and the lamp make up to color or saturate the signal. 
 
Brickwall Limiter Stage
- Fixed ultra fast attack trimed in factory.
- 12 steps threshold +6dBu to +5dBu.
- 8 steps release 10ms to 1.5s.
The last output stage is a Brickwall Limiter with 12 Threshold positions. Each position is factory set to a negative tolerance. For example, the +ddBu position will have a real level of -0.00 dBfs, which ensures no digital saturation. The Limiter does not defy the laws of physics, but by pushing the Make Up to its limits, the dynamic range will be reduced and the overall volume impression can increase considerably without exceeding +4dBU (0db VU).