I have a pair of ESS Transtatic 1 speakers which I purchased new about 40 + years ago. I have had to repair two of the RTR Es screens over the years
Successfully. However the Mylar film is starting to get a bit funky around the edges and replacements are unavailable. Also am wondering if the xover caps should be upgraded to polypropylene. I believe xover is at 100hz and 1500hz but may be mistaken. Kef racetrack flat woofer, transmission line, Philips midrange in tube with front and rear radiation and 3 RTR screens per unit with 45 degree reflecting panel behind them.
I'm driving them with 2 Crown DC 300 a amps strapped for mono one for each speaker. OC 150 monitor and a Sony TAE-77ESD-ESS preamp.
I realize it's old but so am I at 70+ and am hoping to keep it all alive as long as my hearing remains good. Any ideas?
Successfully. However the Mylar film is starting to get a bit funky around the edges and replacements are unavailable. Also am wondering if the xover caps should be upgraded to polypropylene. I believe xover is at 100hz and 1500hz but may be mistaken. Kef racetrack flat woofer, transmission line, Philips midrange in tube with front and rear radiation and 3 RTR screens per unit with 45 degree reflecting panel behind them.
I'm driving them with 2 Crown DC 300 a amps strapped for mono one for each speaker. OC 150 monitor and a Sony TAE-77ESD-ESS preamp.
I realize it's old but so am I at 70+ and am hoping to keep it all alive as long as my hearing remains good. Any ideas?
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Any old xover caps that are electrolytic should be upgraded to polypropylene, or new electrolytic if price is prohibitive.
Mylar is easy to source from ebay, but getting a good conductive spray maybe difficult depending on where in the world you are.
The main concern I would have is how hard it is to open the electrostatic drivers to replace the mylar.
Mylar is easy to source from ebay, but getting a good conductive spray maybe difficult depending on where in the world you are.
The main concern I would have is how hard it is to open the electrostatic drivers to replace the mylar.
Thanks for your suggestions. Re the screens separation the RTR panels are glued with a brittle glue which releases quite easily if one stands the plastic on edge then places a flat bladed screwdriver along the seam and gives an impact whith the heal of the hand popping the glue then working the halves apart carefully. It's finding the right Mylar, stretching etc that seems daunting. I didn't realize it had to be sprayed, I imagined it came conductive. My repairs have been carefully moving the sagging grid conductor away from contact with the Mylar which seems to correct the malfunction as long as the Mylar hasn't lost its integrity. Does the film have to be coated on both sides or will dielectric absorption allow it to function one sided?
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Gjim, back when that speaker was current, I worked at Infinity, a competitor. Some of our products were also electrostatic. Tweeters were RTR, like yours, but we made our own midrange panels. "Dow heavyduty food wrap" is the mylar we used. I'm not sure exactly what we sprayed it with, but we stretched the mylar over low heat for a few minutes and sprayed the coating on....
There are several threads here about building panels.
There are several threads here about building panels.
Mylar
Great tip! Do you by any chance remember the mil thickness? I was wondering about using one of those Mylar balloons as fodder but may be too thick. Was the spray a metallic aluminum or some type of graphite or perhaps a fine MDS powder which would imbed in the surface or? Yes I'm remembering something called servo statics by Infinity that were quite good. I wish I could have worked there, would have been a great learning experience. I'm partial to full range E S but hard to get the fundamental lows.
Koss made some large full range e s that were quite good but I preferred the RTR for highs. I guess ultra low mass is the secret there. In my speakers the xover to the RTRs is 1.5khz so they do the lion's share of the work.
Great tip! Do you by any chance remember the mil thickness? I was wondering about using one of those Mylar balloons as fodder but may be too thick. Was the spray a metallic aluminum or some type of graphite or perhaps a fine MDS powder which would imbed in the surface or? Yes I'm remembering something called servo statics by Infinity that were quite good. I wish I could have worked there, would have been a great learning experience. I'm partial to full range E S but hard to get the fundamental lows.
Koss made some large full range e s that were quite good but I preferred the RTR for highs. I guess ultra low mass is the secret there. In my speakers the xover to the RTRs is 1.5khz so they do the lion's share of the work.
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I have no memory of the specifications, other than noting that the box it came in said, "Dow Heavy Duty Food Wrap" on it. There are a variety of substances in use for making the film conductive, see other threads here. You only need spray one side. The coating should be only slightly conductive, so metallic coatings are not really needed.
Popular coatings include, "Licron", diswashing soap, graphite, etc. Good luck...
Popular coatings include, "Licron", diswashing soap, graphite, etc. Good luck...
There's someone selling 1mil "Melanex" Polyester (Mylar) film over at eBay. Not sure I can put the link here, but a search there should find it for you.
Or better, someone is also selling film at the 'bay, intended for fixing Quad electrostats -- search "Dupont Mylar C 12um", about half mil. Decent price, too.
Great. I suppose the thinner the better as far as transient response goes but more delicate as well. I have an old white Jansen panel I can learn on.
Hi,
You might try the ER Audio site. They sell replacement mylar, conductive coating, etc and
the owner, Rob Mackinlay, is very helpful.
Electrostatic Loudspeakers By ER Audio
John
You might try the ER Audio site. They sell replacement mylar, conductive coating, etc and
the owner, Rob Mackinlay, is very helpful.
Electrostatic Loudspeakers By ER Audio
John
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