Gyraf G-10

The Gyraf Audio G10 Vari-Mu Compressor is a true tube stereo compressor based on the classic variable-mu principle. This method – controlling the gain by altering quesient current in differential tube pairs – is much faster than the optical method.

The Gyraf Audio G10 Vari-Mu Compressor features a classic design that will fit into every studio. The two handles make it easy to transport or move the product, and the material of the switches is a must feel experience. The G10 is as standard available as a 230V mains unit – other mains voltages will be made on request (at no extra cost) – please specify when ordering.

Tech
The Gyraf Audio has recently further developed the G10 into the G10/Hpf version, which allows high-pass filtering of the controlling sidechain signal - allowing harder compression to bass-heavy material without pumping artefacts. The selection is done as 3 extra steps on the bypass switch, which gives cutoff frequencies of ca 80, 160 and 300Hz at a soft 6dB/oct. It is based on a very minimalistic true-differential signal path from input to output, using very, very tightly selected PCC189 (7ES8) remote-cutoff dual triodes for the VCA stages, and E88CC (6DJ8) low-noise triodes as cathode followers for the output stage drivers. Both tubes are still fairly easily available throughout the world.

Changes
The controls on the Gyraf Audio G10 are the input level pot, the threshold pot, the ratio pot, the attack pot, the release pot, the outpot level pot and the bypass switch. The input level pot is positioned right after the input transformers, thus allowing you to control the input level, the "drive" for the compressor. The Ratio pot controls the amount of compression in relation to changes in the input level, that is, for the part of the signal that exceeds the threshold value that is set. Setting Ratio fully counter-clockwize will deactivate compression. The Attack pot controls the time the compressor takes to react to a rising input level. The Release pot controls the amount of time it takes from the input signal falling below threshold, to the gain reduction being returned to unity. The Output level pot controls the signal level to the output driver stage and the output. The Bypass switch bypasses the unit completely. The hard way. - A relay simply takes out the active electronics and shorts the input to the output connectors.

Gyraf Audio G10 Vari-Mu Compressor Features

• A true tube stereo compressor based on the classic variable-mu principle
• Based on a very minimalistic true-differential signal path from input to output
• Input level pot is positioned right after the input transformers
• Threshold pot controls at what level the compression will set in
• Ratio pot controls the amount of compression in relation to changes in the input level
• Attack pot controls the time the compressor takes to react to a rising input level
• Release pot controls the amount of time it takes from the input signal falling below threshold, to the gain reduction being returned to unity
• Output level pot controls the signal level to the output driver stage and the output
• Bypass switch bypasses the unit completely

Gyraf Audio G10 Vari-Mu Compressor Specifications

• Type: Tube Stereo Compressor
• Input/Output: Floating, Transformer Balanced
• Input Impedance: 10K Ohm "Bridging" Type
• Output Impedance: Less than 1K Ohm
• High-Pass Filter: Cuts Off at 80, 160 & 300Hz at a Soft 6dB/oct
• Controls: Input Level Pot, Threshold Pot, Ratio Pot, Attack Pot, Release Pot, Outpot Level Pot & Bypass Switch
• Carrying Handles: 2
• Mains Voltages: 230V