In the 1980's, Quad released the ESL-63. It began what I call the modern Quad electrostatic loudspeakers. The modern line started with the ESL-63, then was followed by the 988, then the 2805, and then the 2812. When the 988 was released, Quad also released a larger speaker with 50% more panel area designated the 989. This larger speaker was followed by the 2905, and finally the 2912.
The modern Quad ESLs use a sectionalized panel approach like the original ESL, but unlike the Original, all the stator spacings are the same, and the panel area is divided into 8 annular regions. The center region plays full range, and moving outward the signal is delayed and the high frequencies are filtered out in subsequent rings. This technique makes the flat panel radiate a wave front that is similar in geometry to a point source located a short distance behind the speaker.
Modern Quad Electrostatic Loudspeaker References
- Early Production ESL-63 Schematic
- Middle Production ESL-63 Schematic
- Late Production ESL-63 Schematic (and later models)
- Early Quad ESL-63 Owner's Manual
- Later Quad ESL-63 Owner's Manual
- Early Quad ESL-63 Sales Flyer
- Early Quad ESL-63 GFD Stand Flyer
- Early Quad ESL-63 Stand & Deliver Stand Manual
- ESL-63 Service Manual
- 2905 Service Manual
- ESL-63 Packing Using Home Store Materials
ER Audio in Australia is a great source for mylar, coatings, power supplies, input transformers and complete ESL kits. His prices are very good, and they ship promptly. Mylar is very well packed in a double mailer tube arangement. The products and service I've gotten from these guys is first class. I highly recommend them.
