From the Janszen website:
KLH Nines!
We have acquired a dozen pairs of KLH Nine full range electrostatic speakers over the last ten years. This is the still excellent sounding and history making design that my father Arthur A. Janszen created at JansZen Laboratory and had in field tests in 1957, and which was then taken on by KLH and put into production at the end of the 1950's.
The KLH Nine was the first truly full range electrostatic speaker. It was not long ago pronounced one of the 12 most significant speakers of all time, and been written about repeatedly over the years (example).
It was in production for nearly twenty years. There are still many of them stored in people's garages and attics, and some still in use.
Although many are still operating to some degree, it is unusual for any to be reaching their original potential, however, for a few reasons: (1) failure of the antiquated selenium rectifiers in the bias supply unit, which were all that was available in the 1960's for high voltages, (2) failure of the carbon composition resistors in series with the bias supply, and (3) the accumulation of soot on the woofer panels causing leakage paths for the high voltage.
We are in the process of completely dismantling and rebuilding some of these pairs to better than original condition, with better joinery and finishes, fully rebuilt transducers, and modernized supply units fitted with components that will not age appreciably over the next decades. They'll come with a full, transferable, two-year warranty.
These speakers had a list price of about $2,000/pair in 1960. With inflation, they would cost about $15,900 today. We will be offering pairs restored to better than new condition for half that price, $7,950, and are taking pre-orders now. We will certainly be able to make at least four excellent pairs from the dozen we have, and possibly as many as ten.
To ask about these, just send an email to KLH9@janszenloudspeaker.com or call us at +1 (614) 448-1811.