The most common problems with the electrostatic panel on DM 70’s is loss of output due to splits occurring in the diaphragm, arcing damage causing polarising voltage leakage (EHT) and accidental damage.
It is an easy task to replace the diaphragms on these speakers, re-coat them and repair the damage caused by over enthusiastic use of the volume control (arcing or sparking between stators)!
This will bring the performance of the ESL panel back to “as new”.
Generally, the electronics in these speakers are quite robust and rarely give trouble, the most common problem being failure of the EHT supply components. If this is suspected, feel free to contact us to receive troubleshooting advice.
The kit contains sufficient diaphragm film and conductive coating to replace the diaphragms many times and comes with all components and adhesives likely to be needed, plus full instructions.
B&W DM70 Repair Kit ASK Rob |
|
Material |
Quantity |
| Diaphragm 3.5 µm, DuPont Mylar C | 6 metres |
| Diaphragm Adhesive | 25 ml bottle |
| Foil Tape, 4mm wide | 4 metres |
| EHT Cable | 3 metres |
| Polyurethane Adhesive | 50 ml bottle |
| Tensioning Gauge | 1 |
| Clear, conductive coating | 25ml bottle |
| Sponge Applicator | 1 |
| Large Paint Brush | 1 |
| Small Paint Brush | 1 |
| Plastic Sheet | 1/4 |
| Rubber Gloves | 2 Pairs |
| 180 Grit Oxide Paper | 2 x 250mm sheets |
| Gaffa Tape | 1 Roll |
| Nylon Screws | 100 |
| Steel Nuts | 100 |
| Syringe | 1 |
| 100 MΩ Resistors | 2 |
| Full Instructions | 1 |
| Air Gap Spacers (shown at left) | Complete Set (2 spkrs) |
| N.B. There are 2 types of spacers for early and late models. We need to know which type you have so we can supply the correct spacer. The best option is to take a photograph of the panel if it has not been dismantled or of the spacer if it has, and send it to us. This will ensure you get the correct ones. | |
Some speakers may have had “dodgy” repair attempts in the past and could have had the air gap spacers damaged during attempts to remove the original adhesive. If you have damaged or broken air gap spacers, there is now no need to be concerned, we are able to supply accurate laser cut replacements.