Transformers mount onto various chassis in several different ways. How the transformer mounts to your chassis determines the mounting style you order.

Most transformers have standardized mounting styles. However, within the industry there are several naming conventions used. Mercury has adapted the following simple and easy-to-remember system.

When ordering you'll need to know the following --

  1. Layout: 2- or 4-hole.

  2. Method: Horizontal, Vertical or Flat.

  3. Footprint: the center-hole-to-center hole dimensions (in inches). The distance between the center of each of the screw, or bolt, holes that will be used to mount your transformer.

  4. Style: A-Frame, "Special Brackets" (designed to accommodate many of the original Fender amps), L-Bracket or UTM (Universal Transformer Mounting) bracket. (See illustrations below.)

4-Hole Mounting Styles
(Click on artwork to see a large version)

Horizontal Mount -- the bobbin is in a horizontal position --

Photo shows our "Special Brackets" for some Fenders

Vertical Mount -- the bobbin is in a vertical position

Flat Mount -- the transformer's laminations are parallel to the chassis

2-Hole A-Frame Mounting Styles

A-Frame Horizontal Mount -- the bobbin is in a horizontal position

A-Frame Vertical Mount -- the bobbin is in a vertical position

2-Hole Mounting Style (A-Frame)

4-Hole Mounting Style (photo shows our L-Brackets)

The UTM Bracket System


UTM brackets also act as a reinforcement to strengthen the chassis for most transformer applications. (Available in black, gold and silver!)


  1. Endbells (caps that cover the bobbins and laminations) for transformers are optional. Ask your Mercury Representative about color options and custom graphics. 

  2. Not all transformers and chokes can be fitted, or need, endbells. For example, chokes and single-ended outputs are gapped, therefore endbells are not used because they will short the gap. If you have any questions, please consult your Mercury Representative.

  3. A-Frame Mounts are standardized.

  4. 4-Hole Mount transformers mount in several ways, including L-Brackets, "Special Brackets" or UTMs.

  5. UTMs (Universal Transformer Mount) brackets will greatly increase your mounting options and are available in several colors. They can help to strengthen the chassis, especially for Flat Mount applications. For more information on UTMs please follow this link.

For more information, assistance, quotes or inquiries:

10050 Remmet Ave. • Chatsworth, CA 91311 • FAX (818) 998-7835

(818) 998-7791