Anyone around here built their own electrostats?

[geolemon]

I'm new here, but looking forward to hopefully discovering more DIY nutcases like myself. I've always got some odd project going on, whether it's in-car line arrays, or scratch-built rotary-servo subwoofers... I'm interested in "non-standard" or alternative truly hi-fi technologies. Hell, I'd like to seek out a pair of Plasma tweets to audition of anyone had one that were reasonably near me... But this isn't about plasma tweeters.

I've seen web pages on DIY electrostats before, but never had truly entertained the thought of trying to build my own... to be honest my listening in the home is less critical to me, as I'm always moving around, working on something, I don't sit still.

This past week, I listened to a set of Martin Logan Clarity electrostats that have convinced me that possibly that is the set of speakers destined for my home.
I say this because remarkably, no matter where I moved about in the room, the tonality and clarity were virtually unchanged, really something to experience.
And interestingly, that's not to say they didn't image.
If you haven't heard the Clarities, I definitely recommend giving them a listen, and do as I did... really honestly remarkable.
For $2700 I thought they were actually a good deal (and that says something, since I wouldn't pay $2700 for a set of home speakers).

But at any rate, I was surprised at the detail that the electrostats could yield, truly shocked at the "room filling" sound, and I'm curious about possibly building my own set.

Has anyone around here built their own electrostats?
Do you have any comments regarding the cost, special skills or tools required, any notable experiences you faced during the construction, or use of the electrostats?
Any comments on the fidelity of the DIY electrostats compared to manufactured electrostats like the Martin Logans?

[MarcelvdG]

I haven't, but a colleague of mine is busy building DIY electrostatics of his own design. Some of the mistakes he made and a lot of the lengthy calculations he made would have been unnecessary if he had only read

Peter J. Baxandall, “Electrostatic loudspeakers”, chapter 3 of John Borwick (editor), Loudspeaker and headphone handbook, Focal Press, Oxford, 1997, ISBN 0-240-51371-1

before starting. If you want to understand ESL theory, you should definitely read Baxandall's chapter.


Besides,

Roger R. Sanders, The electrostatic design cookbook, 1995, ISBN 1-882580-00-1

contains lots of practical tips on do-it-yourself ESL construction. Almost everything Sanders writes about theoretical matters is plain wrong, but he gives very valuable information about practical things like what types of glue stick to mylar.

[SY]

I've done a rebuild, but not a scratch build. Mr. Diaphragm, that's me. Do check out the stuff that Sheldon Stokes has done; he built his from the ground up. And read everything that Peter Walker ever wrote- his patents can provide hours of informative enjoyment.

[promitheus]

The best books are the following:

Electrostatic Loudspeaker Design and Construction
Ronald Wagner
ISBN: 0-9624-191-6-8

The Electrostatic Loudspeaker Design Cookbook
Roger R. Sanders
ISBN: 1-882580-00-1

For me the best book on the subject with 3 real working projects in the book including crossovers, electronics and other theory.

Also search the net for the following:

DIY ESL 184 by Geert Vijncke
DIY Matthew Ankers Electrostatic Loudspeaker web site.
Mark Rehorst Web site.

[geolemon]

Thanks for the tips - I'll seek out those books at some point over this winter, and I'll keep those words regarding Sanders in mind as I'm reading.

Just curious, as you mention "Sheldon Stokes" and "his patents"...
And I note that there are relatively few ESL manufacturers in the market, as there are relatively few servo-loudspeaker (not servo feedback loudspeaker) manufacturers on the market...
Is Sheldon Stokes to Electrostatics what Tom Danley is to Servo-motor loudspeakers?

I may first venture down an easier road...
I'm pondering if much of the "room-filling" qualities of the Electrostats are due to their functional dipole behavior.

I've got four Bohlender Graebner Neo3PDR's that I've really never done anything with... they might make a fun and easy project for my office here, something relatively small to listen to in here...

Trying to approach them scientifically, so I'm not left later trying to figure out exactly why I did or didn't like the sound of them.

[SY]

The patents I was talking about were Peter Walker's. There is no better source- his Quads are still the standard by which people judge ESLs.

Sheldon Stokes, a diyAudio member, did a very nice DIY design and published details on his web site. A few minutes with google will turn it up.

[promitheus]

The Quads have a very nice Patent and idea behind them but are not at all suited for DIY. It´s too complex. People have been making simple designs that work very good.

[peterr]

Here you can find about all the info you need: the esl circuit.
I have built my own ESL's from scratch and am very pleased with them.
In the Netherlands we have a small but active community of Esl builders (esl club, It is all in dutch I'm afraid)
My latest project has been a pair of Valve monoblocks to power the speakers directly, bypassing the esl's stepup transformer.

[geolemon]

Oh, sorry.. I quoted the wrong name.

It doesn't sound like anyone owns "all the patents" though, that would effectively lock up the concept of producing electrostats...
...which is essentially what Tom Danley of ServoDrive (www.servodrive.com) has the luxury of with his all-encompassing patents, which essentially cover the production of any servo-motor powered loudspeaker.

I don't have anywhere to audition Quads around here...
...but I'm actually flying out EARLY tomorrow morning to Las Vegas, for the annual Consumer Electronics Show (CES) for 4 days.
I'll hunt them down, believe me.
(and any other unique reproduction technology, for that matter)

And thank you Peterr, I have a friend who is of Dutch descent, his wealthy parents actually just retired early and moved back.
Possibly (unfortunately more slim-to-none, as I never really see him ) I could talk him into sitting down with me to look that site over...
...I don't know though, sounds impractical.

But your first link looks great, thank you very much!

[MarcelvdG]

QUAD has some very important patents on electrostatic loudspeakers, but most of them are over 20 years (over 23 years for the Americans) old and therefore expired.