My latest ESL project

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RAH

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Great stuff you make. Well done. They look great and I am sure they sound fabulous too.
 

JonFo

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Very nice, now, tell us more about the design and build.

I'm specifically interested in the ESL energizer and step transformers, are those Amplimo toroids?
 

Jazzman53

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Very nice, now, tell us more about the design and build.

I'm specifically interested in the ESL energizer and step transformers, are those Amplimo toroids?
The bias supply is a small 115/230 volt transformer feeding into a simple diode/capacitor voltage multiplier circuit (3.2kVDC). The step up transformers are tandem pairs of inexpensive 230V/2x6V toroidal power transformers (way cheaper than Aplimo's and perform almost as well in a hybrid setup).

The really trick part of these speakers are the stepped-frequency/stepped-phased-array wire stators; which bend the wave front electronically to give wide, smooth trending dispersion.

You can read all about it on my website here:
 

JonFo

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The really trick part of these speakers are the stepped-frequency/stepped-phased-array wire stators; which bend the wave front electronically to give wide, smooth trending dispersion.
I figured that's what the array of resistors at the base of the panel was for, a shaded horizontal output. Nice.

The step up transformers are tandem pairs of inexpensive 230V/2x6V toroidal power transformers (way cheaper than Aplimo's and perform almost as well in a hybrid setup).
Cool, please PM the specs for the step-ups.

And once this crazy pandemic is over, I need to go hear your speakers, and you need to hear my setup, as we're both in GA (6hrs away though). You need to listen to mine while they are still dipoles, as my next step is converting them to monopoles with associated line-array mid-bass columns (similar to my center).
 

Jazzman53

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Here's a link to purchase those transformers:

If you wire a pair of them in tandem as shown in the schematic on my website; the winding ratio will be 76:1 step-up.

These type transformers are not sold in the US. They are made to step-down 230V European house current to 6 volts.

You can buy 2X115V/2x115V toroids in the US, which will also work, and give the same step-up ratio. However, their bi-filar wound secondaries have higher winding capacitance and are more prone to flash-over.

I will PM you my address and phone number. Love to have you drop in for a listen.
Charlie
 
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