Full-Range Dutch ESL Project File translated
It's been kinda quiet lately, thought I'd post a translated version of a FR ESL project posted on the dutch ESL-club site.
If you haven't visited this site before, it is worth your while to poke around some.
To view the site thru the Google Translator:
Here is the FR project:
Electrostaten Project 11
The Google translator did a half-way decent job, I thought.
I had to shrink the pics a bit to get under the forum upload size limits.
To see the full size images you can download the dutch version here:
Thanks for the link!
That's a very impressive build. I like the diaphragm tensioning technique.
good stuff !
this is a vey helpfull article regarding the wire stator design and build
This was also the first time I had seen anybody else using silk-screen mesh for damping the diaphragm resonance.
I struggled with finding a way to damp the diaphragm resonance without ruining the midrange clarity.
Experiments last year showed the silk-screen mesh to work very well for this application.
Attached is another construction article from the dutch website that I translated sometime last year.
Looks like it might have been slides for a presentation at a club meeting.
Thanks for sharing, the pics are worth a thousand words. I would enjoy a project like that someday. What do you think the estimated cost for materials would be for say, 12 by 40"? And what kind of voltage for the step ups are required? As with everything on this site, I have never seen this before. A WHOLE lot different the panels I have. But thats freaking awesome.
not to mention it has taken you a while to post as well, always like great information. It is a little hard to some sence of the translation, but fascinated with the different wire gauge to achieve a full range at or around 3 ohm. thats my understanding. I am curious if you posted because you own a set or just sharing information, or if you DIY'd a set of your own.
I can see most of the pics in some detail, multi strand wire( but what insulation?) aluminum for a contact point( corrosion?) this will bother me until I build a set. So please share some info, it takes a while to order from over seas, customs and what not.
Yes, my replies are scattered as I am allways looking and listening for something different and maybe something better. Which to me will be a very hard decision, as i have played the ever loving heck out of mine, and still impressed.
So please, share your thouhgts, what does or what is a round about cost in material? (assuminng you have built your own) cost in USD.? I am very interested. thanks again!
What pussles me is the wattage of the equalization resistors. They do not look no more than 2, may be 3 watt.
Resistance is around few hundred kOhms.
Most of the panel (area wise) is driven through 4x390k in parallel: this translates into 4Ohm @ transformer primary.
Besides the ohmic resistance of the secondaries it's almost the only dissipative element in the circuit.
Assuming 1000pF capacitance of the panel, reactive inpedance will be 32kOhm (@5kHz) which is 3 times less than dissipative one.
Vector summing of impedances makes capacitive component irrelevant (almost like short circuit): Sqrt(90000^2+32000^2)=95k
So my question is Where usually recommended 100W sucked out of amplifier dissipates?
One may say, O'K there are other resistors in series at the rest of the panel with even higher resistances. And still wattage is small...
P.S. Simulation shows dissipation level 5-10 times of the resistors' ratings .
P.P.S. Even Allen Bradley carbon comp (dedudction from the picture in the article) are not designed for voltages 1kV across...
I heard those speakers in real life. They sounded very good :)
not sure what you are saying - but you need VOLTAGE to drive an ESL, so the amp "power" is mostly related back to the voltage needed to drive the primary of the stepup transformers that drive the stators, so that enough voltage is produced. Yes, there is some current too, but it's mostly the voltage required.
So you can make direct drive amps, or use OTLs with most ESLs as a result.
This may be what you are interested in... not sure...
I usually use multiple resistors(as do most manufacturers) in series to keep the voltage across the resistors within rating and to share the power dissipation. I attached two examples from Capaciti and Audiostatic. In my experience when playing music single segmentation resistors do seem to work fine as the peak to rms ratio of music keep the power dissipation low. However, if you play loud pink noise or high frequency sine waves, the single resistors will got HOT quickly and burn up if left playing.
Concerning amplifier requirements:
As bear already mentioned, you are mainly interested in voltage output of an amplifier for driving ESLs. So if somebody recommends using a 100W amplifier, what they really mean is that they recommend using an amplifier that puts out about 28Vrms - 30Vrms.
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