Bent Audio MU Step-Up Transformer - Like New, Never Used

Bent Audio MU Step-up Transformer (copper version) - Like New, Never Used

This listing is for a pair of Bent Audio MU Step-Up Transformers (copper version) in like-new cosmetic and new, never-used operational condition. The Bent Audio MU Step-Up Transformer (SUT) is a discontinued and rarely available highly regarded device within the audiophile community, known for providing exceptional cartridge gain with a very low noise floor and natural sonic characteristics.

Key Features & Technology

The MU SUT is a passive device that uses the physics of induction (rather than active electronics) to achieve gain, which many purists prefer for its inherent lack of active circuit noise and distortion characteristics.

• Customizable Ratios: The units can be internally rewired for different step-up ratios, such as 1:5, 1:10, or 1:20, providing approximately 14 dB, 20 dB, or 26 dB of gain respectively.
• Loading Flexibility: Features easily accessible external binding posts, allowing users to conveniently add custom loading resistors to optimize the impedance match for their specific cartridge.

Note on Gain Setting: I can no longer recall if I originally ordered the transformers internally wired as 1:10 or 1:20. The buyer will need to verify the internal wiring or test the unit to confirm the exact ratio.

Condition & What's Included

The transformers are in like-new condition, having been carefully stored in a smoke-free and pet-free household. There is only one light scratch I could find (see provided picture); otherwise, these transformers are in essentially new, never-been-used condition.

Included in the sale are:

• The pair of Bent Audio MU Step-Up Transformers (copper version).
• All 16 of the original pairs of load resistors (marked and in their original packages—see photos).
• A copy of the original hook-up email from John Chapman detailing connection and loading strategies (see photos).

Often Noted Sonic Highlights

• Exceptional Soundstage: Consistently praised for outstanding depth, width, layering, and center fill.
• Quiet Background: An incredibly "black" background due to excellent shielding and passive design.
• Natural Tones: The copper version is known for a full, rich, and natural tonal balance.

Seller Notes

While I never had the opportunity to enjoy these transformers myself, it didn’t make sense for these incredible items to remain sitting in a box in my closet. Realizing my audio journey is heading in a different direction and the idea of building a 100% analogue system has waned, I am selling them and truly hope the new owner will enjoy them to the fullest.

Local Pickup Option:

If you are located in or near the California South Bay, you are more than welcome to pick them up in person, and I will refund the shipping charge. They are already packaged, so you will still get the unpacking experience.

I also have two other items (VPI Industries Scout 1.1 and PrimaLuna ProLogue 2) being auctioned that can also be picked up in person with the shipping being refunded to the purchaser(s).