Archived from groups: rec.audio.high-end (
More info?)
On 17 Apr 2005 15:13:40 GMT, Gene Poon <sheehans@ap.net> wrote:
>none wrote:
>
>
>> I've got an old pair of Jansen speakers with the electrostatic
>> tweeters. They're four array radiator types.( four inch square or so
>> with four to a box.)
>> I'm thinking about putting them in another speaker box project I'm
>> working on and could use some advice from any who've had any
>> experience with these type of tweeters.
>> One of the individual radiators is badly damaged and I was thinking of
>> paring them down from four to just three as it might be impossible to
>> get replacement parts for anything this old. This shouldn't be a
>> problem should it?
>> Also they've got a heavy buildup of grime on them from extended
>> storage. What's the best way to clean them off? (I was thinking a bit
>> of simple green followed by rinsing with water, then blowing off with
>> compressed air. Or would it be safe to use a contact cleaner?
>> Thanks in advance for any info regarding these units.
>
>=======================================
>
>Please note, it's "Janszen" with a "Z", after their inventor, US Navy
>engineer Capt. Arthur Janszen. Some of the advertising even had the
>name as "JansZen" with a big "Z" so people be less likely to confuse the
>product with "Jensen."
>
>Do not use anything liquid on the screens. The polarizing voltage is
>1100 volts and if there is any moisture left in them, you will risk
>arcing or damage when they are turned on. Brush them lightly with a
>soft brush to remove the dust, or blow them lightly with air.
>
>Dropping from four to three screens will drop efficiency, maximum output
>and power handling by 25%.
>
>Many of these, after long storage, will suffer from breakdown of the
>connection from the center terminal (on the inside of the screen) to the
>metalized mylar diaphragm. Symptom of this is low or no output. Don't
>be surprised if it doesn't work.
>
>The efficiency of those tweeters is relatively low. At highest output
>(which was adjusted by altering the polarizing voltage down from the
>maximum 1100 volts), they were barely a match for the AR-1w (the woofer
>section of the AR-3). I paired a set with a pair of old AR-2 (tweeters
>disconnected) once, just as an experiment, and the woofer predominated.
> Just about any modern woofer is more efficient, due to more powerful
>magnets and improved materials, and the use of ducted ports on most.
>
>Sometimes an old set may have bad rectifiers in the polarizing supply.
>Early ones had selenium rectifiers that have probably long gone bad.
>Just be aware if repairing it, that it's an 1100 volt supply. A common
>1N4004 diode won't do the job, even though the current draw is minimal.
> And be very careful poking around inside, for your own safety.
>
>That said...if you have a good-working set of Janszen electrostatic
>tweeters, and they are well matched with your woofers, their performance
>is glorious, if somewhat beamy due to the four flat radiators. That was
>my preferred speaker system for years, and although they aren't hooked
>up now, I still have my two Janszen 130 tweeters, the pair of AR-3, and
>a pair of cast-frame AR 12-inch woofers which I bought secondhand, for
>"just in case" replacement parts.
>
>-GP
Thanks for all the info.
I had these things collecting dust in the back of my warehouse for
years and thought it'd be nice to put them in a pair of studio
monitors I'm building.
Someone had tried to pry out one of the units and cracked it along the
edge, it did straighten out though and physically looks fine.
They're 5 inch square with the patent # 2,896,025 on the edge if that
helps ID them for you.
They're really grimey from the long storage and will have to be taken
apart for cleaning if you could give me details on how to do that.
(I've done alot of electronic repair in my time so it's not beyond my
ability, just need the details on these particular electrostats.)
If you have links to any sites on these tweeters it'd be a big help.
I think they may be the 130's(I've stripped all electronics/drivers
out of the boxes). There was nothing on the boxes themselves to
indicate model.
The power supply/comtrol unit is all solid state with 12 caps, 2 5000
ohm resistors various other small resistors/diodes as well as a
transformer coil and the choke coil and cap for the woofer.
The control pot is a 20meg wire wound.
Hope this helps.
I do still have the woofers that came in the boxes and they are in
near mint condition.
12 inch with a rubberized 5 pleat edge and heavy cone.
They test out really good for being as old as they are.
I'd put them up against most made today, will probably put them in
some smaller boxes in some future project.
Thanks again for all the info.