I've been looking at some vintage electrostatic speakers like Acoustats and Quads. What are the possible age-related problems to watch for in electrostatic drivers?While I don't have experience with Quad's electrostatic speakers, I have owned since new a pair of Acoustat Model 2 electrostatic speakers of which I recently completed a full restoration.
If purchasing used, whichever make or model of vintage electrostatic speaker being considered, recommend inspecting closely for any improper shipping/handling damage, or damage from poor storage (frames bent, diaphragms broken, water entry etc.).
Although I cannot speak for every Acoustat owner, I'm happy to share some of the age-related problems I experienced with my Acoustat Model 2s, along with what I did to resolve the issues and restore these beloved speakers to like new condition.
1. Aging electronic components in the Interface.As expected with +40 years old high-voltage electronic components, these parts can deteriorate over the years.
Good news is replacement parts are commercially available and not difficult to install.
Please see report '
Acoustat Magne-Kinetic Interface MK-121-2 - A Successful Restoration'.
https://www.diyaudio.com/community/threads/acoustat-magne-kinetic-interface-mk-121-2-a-successful-restoration.404764/2. Accumulation of dust and foreign particles, and high-voltage stator wires detaching from the lattice frames. Both issues can be fixed by very carefully cleaning and reattaching the high-voltage stator wires to the lattice frames using strong adhesive.
Please see report '
Acoustat Stator Wire Repair: Hints and Lessons Learned'.
https://www.diyaudio.com/community/threads/acoustat-stator-wire-repair-hints-and-lessons-learned.404881/3. Loosening of, or wrinkles in the mylar diaphragms.While other Acoustat owners have commented on the effectiveness of heat shrinking to restore diaphragm tautness, in my case there wasn't much wrong with the diaphragms in my speakers, e.g., no noticeable looseness or wrinkles.
Nevertheless, I did experiment with heat shrinking, please see report '
Acoustat Mylar Diaphragm Heat Shrinking: Hints and Lessons Learned'.
https://www.diyaudio.com/community/threads/acoustat-mylar-diaphragm-heat-shrinking-hints-and-lessons-learned.407546/While it's each individual's opinion, I'm very pleased with the sound quality from my vintage Acoustat Model 2s, likewise I've heard similar endorsements from other owners and makes of electrostatic speakers.
Hope these comments are helpful.
John
