user manual
TL A
udio
®
Ivory 2 Series
5001
QUAD VALVE PREAMP
TL Audio Ltd, Letchworth, Herts, SG6 1AN, UK
email: info@tlaudio.co.uk web: http://www.tlaudio.co.uk
CONTENTS
1 INTRODUCTION
2 PRECAUTIONS
3 INSTALLATION
3.1 AC Mains Supply
3.2 Audio Operating Level
3.3 Microphone Inputs
3.4 Instrument Inputs
3.5 Balanced Outputs
3.6 Unbalanced Outputs
3.7 Ventilation
3.8 Rear Panel
4 OPERATION
4.1 Front Panel
4.2 Microphone Inputs
4.3 30dB Pad
4.4 Phantom Power
4.5 Input Gain
4.6 Drive and Peak LEDs
4.7 90Hz Filter
4.8 Phase Reverse
4.9 Instrument Input
4.10 Output Level
4.11 Optional DO-4 Digital Output Card
5 GETTING STARTED
6 SPECIFICATIONS
7 SERVICE
1. INTRODUCTION
Congratulations on purchasing the Ivory 5001 Quad Valve Preamp by TL
Audio!
The T L Audio Ivory 2 Series consists of a range of hybrid valve signal
processors, which utilise low noise solid state electronics in conjunction with
classic valve circuitry to produce audio processing units offering very high
quality signal paths with the unique valve audio character. The Ivory 2 Series
units offer comprehensive control facilities, whilst remaining straightforward to
operate, and represent excellent value for money.
The 5001 Quad Valve Preamp is a four channel discrete valve microphone
preamplifier that also offers an instrument DI input on each channel. Featuring
very low noise and an exceptionally wide bandwidth, the 5001 provides
continuously variable input and output gain controls, 30dB pad, 90Hz high
pass filter, phase reverse and independently switched +48V phantom power.
The block diagram of one channel of the unit is shown in Fig.1. The
microphone input is via a balanced XLR connector, with phantom power
applied via a front panel switch. The gain of the input stages is controlled by a
continuously variable rotary control, providing between 16 and 60dB of gain on
the mic input. A switchable 90Hz high pass filter (12dB per octave) is provided
to reduce unwanted background low frequency noise, such as traffic rumble or
wind effects.
The second stage of the 5001 consists of a twin triode valve (vacuum tube)
circuit. The characteristic valve sound may be subtly introduced or used to
effect by increasing the input gain. A variable intensity yellow “Drive” LED
monitors the input to the triode circuit to indicate the degree of valve “warming”
that is being introduced. Four red LEDs show peak levels and are calibrated
for +8dB, +12dB, +16dB and +20dB of output, making them ideal for
monitoring levels into a digital recorder.
Phase reverse may be applied, before the output level control. The output
level control allows gain matching to other integrated equipment (e.g. a mixing
console or tape machine). The combination of input and output gain controls
allows a degree of variation in the sound characteristics based on the
operating level through the valve stages. Keeping the input gain low will
produce a clean uncoloured sound, alternatively pushing the input gain will
drive the valves and add the characteristic valve warmth to the signal. The
output gain can be set accordingly without affecting the sound characteristics
of the signal.
Each channel has a balanced XLR line level output at a nominal level of
+4dBu, and an unbalanced jack output at a nominal level of -10dBu. Both are
buffered from eachother and may be used simultaneously.
Finally, the optional DO-4 digital output card may be fitted which provides high
quality A-D conversion of each channel output. The digital output is 24 bit
SPDIF format (via two RCA phono connectors), with switchable sample rate
between 44.1 & 48kHz. An external BNC wordclock input is also provided.
Please read this manual fully before installing or operating the 5001.
2. PRECAUTIONS
The TL Audio 5001 requires very little installation, but like all electrical
equipment, care must be taken to ensure reliable, safe operation. The
following points should always be observed:
- All mains wiring should be installed and checked by a qualified
electrician,
- Ensure the correct operating voltage is selected on the rear panel
before connecting to the mains supply,
- Never operate the unit with any cover removed,
- Do not expose to rain or moisture, as this may present an electric
shock hazard,
- Replace the fuse with the correct type and rating only.
Warning: This equipment must be earthed.
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