GC Audio Analog Riser

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.

3 modes: Dual Mono, Stereo et M/S mode.

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.

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).

Harmonic Stage
• Harmonic generator
• Harmonic mix density

Tube Stage
• Gain 0dB to 20 dB
• 4 stages of 12AY7 tubes on each channel
• High voltage power supply with EZ81 bridge
• Brickwall limiter stage
• Fixed ultra fast attack trimed in factory
• 12 steps threshold +6dBu to +5dBu
• 8 steps release 10ms to 1.5s

Limiter Stage
• 12 Threshold stepped positions
• Each position is factory set to a negative tolerance to avoid peacking