dbx CT3 - Tester for CT3 cables

dbx CT3 - Advanced Cable Tester with Splittable Chassis, Tone Generator, and Multi-Connector Holder

The dbx CT3 is an advanced cable tester designed for fast, reliable cable verification in live, studio, and installation environments. It features two detachable modules — Sender and Receiver —that allow testing of long or patch cord runs without access to both ends. It accepts up to 8 pins and covers virtually all common connection formats: RJ45 (8P8C), RJ11 , DMX 5-pin , XLR (3-pin, male/female), 6.3mm and 3.5mm TRS/TS , MIDI 5-pin (DIN) , RCA , BNC , Speaker Twist (4-pole), and banana plugs with buzzer. It also features a 1 kHz tone generator with adjustable level for signal tracing and functional testing.

The interface displays LED sequences per pin to detect continuity , crosses , shorts and opens , with selectable test speed . The banana plug continuity tester adds a beeper and LED indicator, very useful for quick checks without armored cable. The CT3 operates on two 9 V batteries (one per side); for basic testing, power is only required on the Sender side, while the Receiver requires a battery when using the banana plug buzzer or tone generator. Its ultra-rugged construction and compact size ( 89 × 140 × 37 mm ) make it an essential maintenance and troubleshooting tool.

Main features

• Chassis divisible into Sender / Receiver with thumbscrews, ideal for installed cables.
• 1 kHz tone generator with level control (useful for signal tracing, testing mic/line inputs, headphones or phone lines).
• Up to 8 pins and selectable test speed to display continuity, crosses, shorts and opens by LED.
• Continuity tester with banana plugs and buzzer and LED indicator .
• Supported connectors (2 per type, unless otherwise noted) :
  RJ45 (8P8C), RJ11 ; DMX 5-pin ; XLR 3 pin (1 male + 1 female); TRS/TS 6.3mm and 3.5mm; MIDI 5-pin (DIN); RCA ; BNC ; Speaker Twist 4 poles; banana .
• Power supply : 2 × 9 V (one per side). For basic testing, the battery in the Sender is sufficient; the Receiver requires a battery if using a banana plug or tone generator.
• Dimensions : 89 × 140 × 37 mm (W × L × H). Robust design for intensive use.

Product benefits

• Fast and clear diagnosis : LED sequence per pin and continuity buzzer for instant fault detection.
• True versatility : Test audio, lighting and data cables (XLR, TRS/TS, DMX, MIDI, RJ45/RJ11, etc.) with a single unit.
• Ideal for installation : the detachable chassis allows for checking already embedded or long lines.
• System Check Tool : The tone generator makes signal tracing easy without additional equipment.

Use cases

• Live and tour : Checking multicores , stage patch cords, DMX and network cables before the show.
• Study : noise resolution and channel losses in patchbays, snakes and racks.
• AV Installation : Basic wall mount certification (audio/DMX/network) and preventative maintenance.

Frequently Asked Questions

• Can I test a TS (mono) jack on the TRS inputs? Yes. Insert the connector all the way to the second "click" to avoid bridging the ring and ground; you'll see LEDs 1 and 3 in sequence if it's correct.
• Can I use the tone generator to listen to a speaker or headphones? Yes; the 1 kHz tone can directly excite headphones, and at a low level, a speaker for verification.
• Are there any precautions regarding phantom or other voltages? Do not connect cables to phantom power or any other power supply present: you could damage the equipment.

Description for projects

dbx CT3 Cable Tester ; Detachable Sender/Receiver chassis; Tests up to 8 pins with selectable bit rate ; 1 kHz tone generator with level control; Banana plug continuity tester with buzzer/LED; Connector types (2 pcs., unless specified): RJ45 (8P8C), RJ11 , DMX 5-pin , XLR 3-pin (1M+1F), MIDI 5-pin (DIN), TRS/TS 6.3 mm and 3.5 mm, RCA , BNC , Speaker Twist 4-pole, Banana plug ; Power supply 2 × 9 V (one per side); Dimensions 89 × 140 × 37 mm (W × L × H).