IGS Audio NE71 User Manual

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IGS Audio

NE71

Mic/Istr/Line Mono Preamplifier

User’s Manual

Description

The NE71 is a classic circuit based on the legendary British preamp from
the 1980s. As in all IGS Audio devices the NE71 is a full symmetric
transformer balanced preamp. It is a pure A class circuit with the audio
path reduced to minimum (ultra-short connections between elements).
The construction consists of two steps of gain. The Gain and Output
knobs drive the individual steps. The input is a LL1538 Lundahl
transformer. It is a 1U unit.

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Front panel

1. HiZ input: used for instrument input

2. Mic/HiZ switch: selects input between rear(XLR) and front(HiZ)

3. +48V switch: enables phantom power

4. -20db Pad switch: reduces input gain by 20dB for (Note: for
XLR input only)

5. Phase switch: reverses the phase (Note: for XLR input only)

6. Gain selector: manipulates first stage amplification saturation

7. Output selector: manipulates second stage amplification
saturation

8. VU meter

9. Power indicator

10. Power switch

Rear Panel

From left to right:

1. Power socket 230V AC 50Hz-60Hz

2. Fuse 315 mA Slow Blow

3. Identification plate

4. Output – right

5. Input – right

6. Output – left

7. Input - left

Getting started

1. Connect the NE71 output to your sound interface input with a
symmetrical XLR wire

2. Connect your microphone to the rear XLR input or instrument
into the front HiZ input
!select the input with the HiZ switch

3. Activate the selected input channel on your local mixer

4. Set the Gain switch to 40 and the Output knob to 0

5. For transistor condensed microphones switch on phantom
power (+48V up position)

6. For loud input signals (like snare drum) switch on -20dB Pad
(up position)

7. Switch on the NE71

8. Turn the Output switch until the audio volume is right

9. If volume is out of range adjust the Gain knob

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Typical usage:

• Great microphone preamp with or without phantom power

• Good preamp for any other mono instruments

• Handy for vocal and guitar on stage

• Great for high signals like an acoustic snare or kick

The NE71 design has been well known and appreciated since the 1980s.
This is a preamp that will satisfy all your needs.

Notice

1. No manipulation inside the device by any unauthorized person is
allowed.

2. If you want to mount your device on a rack, then you may remove
the four rubber stands from under the device.

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Specification

• 1 balanced XLR Mic/Line Input

• 1 unbalanced, high resistance HiZ Input on front panel

• 1 balanced XLR Output

• +4dB operating level

• Maximum Output +29 dBV

• Gain 60dB

• HiZ impedance 1 MOhm

• Output impedance 600 Ohm

• Frequency response 20Hz to 20kHz; +/- 0.3dB

• THD <0.01% @ 1Khz, +20dBu

• Dynamic range 109dB

• Meters read VU

• Internal power supply

• Mains consumption 25 Watts

• 230V/110V Power option

• Shipping weight 5 kg

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Warranty

Warrants this device to be free from defects in material and
workmanship for a period of three years. Any device found defective
within three years from the delivery date and returned to the factory
with transportation charges prepaid will be repaired, adjusted, or
replaced at no charge to the original purchaser. This warranty does not
cover expendable items such as tubes or fuses. If the defect has been
caused by a misuse or abnormal operation conditions, the repair will be
billed at a nominal cost