DLK ULM

The DLK ULM (Ultra‑Linear Modules) are one of the rarest and most unusual creations in the entire DLK lineup. Designed in the late 1970s to sit on top of the DLK Model 3 or Model 4, the ULMs were not just add‑on tweeter modules—they were electrostatic high‑frequency units, making them completely unique among DLK products.

These small top‑modules used electrostatic driver technology, meaning they reproduced sound using an ultra‑light, electrically charged diaphragm instead of a traditional magnetic motor and cone. The ULMs stand today as an unusual piece of DLK history:

Sitting on top of custom RS-225 woofer cabinets

Black acrylic tops

Grills

DLK ULK - made by JansZen

The fins had some water damage so each was meticulously cleaned

High voltage internal supply for the electrostatic element

Potentiometer cleaned and new binding posts installed