Srs Labs FB 1650 TLT FT Installation Manual

The Srs Labs FB 1650 TLT FT is a professional audio installation module designed for integration into custom sound systems. It features balanced inputs/outputs, transformer isolation, ground lift switches, level adjustment controls, and a robust metal chassis for rack mounting. This manual covers safety precautions, installation procedures, wiring configurations, initial setup, specifications, and troubleshooting guidelines.

1. Features at a Glance 2. Safety Precautions 3. Installation Overview 4. Specifications 5. Front & Rear Panel Controls 6. Wiring & Connections 7. Initial Setup & Calibration 8. Operational Modes 9. Maintenance 10. Regulatory & Compliance 11. Troubleshooting

Features at a Glance

Key components: Balanced XLR and 1/4" TRS inputs/outputs, Ground Lift switch, Level Control knobs, Transformer Isolation, Rack-mount chassis, Status LED indicators.

Feature	Description
Input Connectors	Balanced XLR and 1/4" TRS combo jacks
Output Connectors	Balanced XLR and 1/4" TRS outputs
Ground Lift Switch	Isolates ground to eliminate hum and buzz
Level Control	Adjustable input/output gain (+/- 20dB)
Transformer Isolation	Provides galvanic isolation for noise reduction
Power Requirement	24V DC external power supply (included)
Chassis	1U rack-mount metal enclosure
Status LEDs	Power, Signal Present, Clip indicators
Frequency Response	20Hz - 20kHz, +/- 0.5dB
THD+N	< 0.01% @ 1kHz

Safety Precautions

Read all instructions before installation and operation.

Ensure the unit is disconnected from power during installation.
Use appropriate mounting hardware for rack installation.
Do not expose to moisture or extreme temperatures.
Use only the provided 24V DC power supply.
Ensure proper ventilation in rack enclosure.

WARNING! Risk of electric shock. Do not open the chassis. Refer servicing to qualified personnel.

Installation Overview

Mount the unit in a standard 19-inch rack using provided screws.

Rack Mounting: Align unit in rack space, secure with screws at front panel.
Power Connection: Connect the 24V DC power supply to the unit and then to AC outlet.
Audio Connections: Connect balanced cables from source to input, and from output to destination.
Ground Lift: Engage ground lift switch if hum is present.
Power On: Verify status LEDs illuminate correctly.

CAUTION! Ensure all connections are secure before applying power.

Specifications

Model: FB 1650 TLT FT
Input Impedance: 10kΩ balanced
Output Impedance: 600Ω balanced
Maximum Input Level: +24dBu
Maximum Output Level: +24dBu
Gain Range: +/- 20dB adjustable
Noise Floor: -90dBu typical
Power Supply: 24V DC, 500mA (included)
Dimensions: 1U x 19" rack width, 7" depth
Weight: 3.5 lbs (1.6 kg)
Operating Temp: 32°F to 104°F (0°C to 40°C)

Front & Rear Panel Controls

Front Panel: Power switch, Level Control knobs (Input/Output), Status LEDs (Power, Signal, Clip).

Rear Panel: Input XLR/TRS combo jacks, Output XLR/TRS connectors, Ground Lift switch, DC Power input.

Level Control: Adjust input sensitivity and output level. Start with knobs at 12 o'clock (unity gain).

Ground Lift: Switch to ON position to break ground loop if audible hum is present.

Wiring & Connections

Use balanced cables for optimal noise rejection. Connect sources to INPUTS, outputs to amplifiers or other processing gear.

Turn off all equipment before making connections.
For XLR: Pin 2 = Hot (+), Pin 3 = Cold (-), Pin 1 = Ground.
For TRS: Tip = Hot (+), Ring = Cold (-), Sleeve = Ground.
Ensure connectors are fully seated and locked.

Tip: Keep audio cables away from power cables to minimize interference.

Initial Setup & Calibration

After installation, perform basic calibration for optimal performance.

Power on the unit and connected equipment.
Send a reference tone (1kHz, 0dBu) to the input.
Adjust Input Level control until Signal LED lights steadily (avoid Clip LED).
Adjust Output Level control to match system requirements.
If hum is audible, engage the Ground Lift switch.
Verify audio quality and level across full frequency range.

Note: For stereo pairs, match level settings on both units.

Operational Modes

The unit operates as a transparent balanced line driver/isolation transformer. No mode selection is required; it is always active when powered.

Transformer Isolation: Always active, providing common-mode rejection > 60dB.

Ground Lift: Manual switch for ground loop elimination.

Maintenance

Periodically inspect connections and clean chassis with dry, lint-free cloth.

CAUTION! Do not use liquid cleaners or aerosols. Unplug power before cleaning.

Regulatory & Compliance

FCC Part 15 Class A: This device complies with limits for industrial environments. CE marked for European compliance. Manufactured under ISO 9001 standards. For technical support, visit www.srslabs.com or contact 1-800-123-4567.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No power / LEDs off	Power supply not connected	Check DC power connection; verify outlet is live.
Hum or buzz in audio	Ground loop	Engage Ground Lift switch; check cable grounding.
No audio signal	Incorrect cabling or level settings	Verify cables are connected to correct ports; adjust Level controls.
Distorted audio	Input level too high	Reduce Input Level control; ensure Clip LED is not lit.
Intermittent signal	Loose connections	Check and secure all audio connectors.

Reset: Power cycle the unit if abnormal behavior occurs.

Service: 1-800-123-4567; www.srslabs.com