Shure

Shure A15BT: Bridging Transformer (Balanced/Unbalanced)

Name: Shure A15BT: Bridging Transformer (Balanced/Unbalanced)
Brand: Shure
SKU: A15BT

★★★★★4.6 (481 reviews)

Bridge balanced and unbalanced audio lines cleanly with Shure's compact inline transformer.

$49.73*$62.00Save 19%

*Price sourced from Amazon.com. Last updated:May 27, 2026.Price and availability are subject to change.

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Overview

The Shure A15BT is a bridging transformer designed to solve one of the most common issues in professional audio: interfacing balanced and unbalanced equipment. When devices with different signal standards need to share a signal path, impedance and level mismatches can introduce noise, hum, and signal degradation. The A15BT sits inline between the two devices and uses passive transformer coupling to match impedances and convert between balanced and unbalanced signals cleanly.

Because it is a passive device, the A15BT requires no external power, batteries, or phantom power, which makes it a dependable set-and-forget link in both permanent installations and live sound rigs. Its transformer isolation also provides an effective break in the ground path, helping to eliminate the hum caused by ground loops between equipment on different electrical circuits. The compact inline housing is built to professional standards and fits neatly between XLR or adapter cables without adding bulk to the setup.

Specifications

Brand

Shure

Model

A15BT

Type

Bridging Transformer

Compatibility

Balanced and Unbalanced Devices

Power

Passive (no power required)

Pros & Cons

👍 Pros

Passive design requires no power source, making it reliable and maintenance-free
Transformer isolation helps eliminate ground loop hum between mismatched devices
Compact inline form factor takes up minimal space in a cable run
Built to Shure's professional audio durability standards

👎 Cons

Limited to bridging balanced and unbalanced connections with no additional signal processing
Small form factor means no labeling or indicators are visible at a distance in dense rack setups
Adds a connection point in the signal chain, which can be a potential failure point in touring rigs
Higher price than generic passive adapters performing a similar function

Frequently Asked Questions

What does the Shure A15BT bridging transformer do?

It allows you to connect a balanced audio device to an unbalanced audio device, or vice versa, by matching signal levels and impedances between the two.

Where does the A15BT sit in the signal chain?

It connects inline between two audio cables or between a cable and a device input/output, acting as an adapter at the point where balanced and unbalanced signals need to meet.

Does the A15BT require external power?

No. As a passive transformer, it requires no batteries or phantom power to operate.

Can the A15BT help eliminate ground loop hum?

Yes. Because it uses transformer isolation, it can break ground loops that cause audible hum when connecting equipment with different ground references.