Aurora Audio GT500 500 Series Preamp

The Aurora Audio GT500 Preamp can accommodate any signal you care to throw at it, including high-level line inputs. The sensitivity switch provides 100 dB of gain adjustment from +80 dB to –20 dB and the level pot allows for fine adjustments. The level pot has an audio taper and is –20 dB at half rotation.

If you have to turn the pot below 1⁄2 way, the sensitivity switch must be adjusted at least 2 clicks more to restore the signal level at the expense of input headroom! Operating the unit with the output level at maximum ensures that you keep the headroom in the designed 26 dB region.

The DI input overrides the normal input and has 10 Megohm input impedance and around 10 dB gain. It can be used (to great effect) with musical instrument pickups, but works equally well with high-level signals like a DAT or CD player. The same gain structure rules apply.

The High Pass Filter is selected by moving its toggle switch to the right and a blue LED will glow to indicate section. Four frequencies are provided with 47 Hz, 82 Hz, 150 Hz and 270 Hz for the selections.

Features:

• Made in the USA (hand-built in North Hollywood)
• All Class A, discrete transistor, transformer coupled through-hole assembled (no surface mount)
• Features Aurora's unique transformers and the same circuitry as the GTQ2/GTP8
• All steel construction of the case and front panel provides shielding
• Input impedance: 1.2 kOhms, transformer balanced and floating
• DI Input impedance: 10 mOhms
• Output impedance: <75 ohms, transformer balanced and floating
• Output drive capability: >+24 dBu into loads of 600 Ohms and upwards
• Frequency response: 20 Hz to >75 kHz ±3 dB
• Distortion: <0.05% @ 0 dBu @ 1 kHz
• Noise: -45 dBu @ 80 dB gain measured 22 Hz to 22 kHz
• Current draw: 100 mA normal operation, 130 mA every mode selected