Summary:
OK for those of you who love classic high performance audio equipment this is a fairly 'esoteric' system. This story goes back to the days when I wporked at the old (now gone) Audio Center in Houston back in 1965. Woody, our resident audiophile 'extremist' had laid some unbelievable story about electrostats on our store owner, JCR and had gotten him to contact the KLH rep and order 4 of the KLH model 9, 6 ft tall wonders. We already had a pair of the QUAD full range electrostats in the large demo soundroom from the previous year also.
When the 4, KLH 9's arrived Woody went ballistic and started running around calling his audio and college friends and spreading the news. He (as always)
wouldn't let anyone else touch the shipment and he personally opened the rather long awkward box that they were packed in. After feverishly moving them all over the soundroom he finally put them in a straight line 4 unit array with
the end units 'towed in' about 15 degrees on the same wall and in front of the K-Horns. His reasoning was that we wwere not really going to compare these to the K-horns anyway what with the huge disparity in efficiency and all (84 or 85 db at 1 meter at 1 watt on the 9's and 104 db at 1 w/1 meter on the K-horns). Anyway woody proceded to drag out an old 2 track Westminister open reel tape with a binaural recording of chamber music from Austria (I think). I was finishing up with a customer when he said 'Hey come listen to this...'

So I went in and there was this not too terribly loud ultra sweet and clear chamber quartet playing a little repetitive Bach thing with a Harpsichord so delicate you could just visualize the thing sitting there somewhere about 5 or 6 feet behind the array of model 9's. This was and still is (in my mind) the most realistic small chamber group reproduction I have ever heard. The only thing I have heard since that comes even close is my friend John's 6 foot tall early Magneplanar (1971) system.

Anyway, Woody was getting that look on his face and he wanted me to go up to the stockroom and help him carry down a pair of Marantz Model 9's, so I went with him. When we found them they were back in the reserved area where stuff waits for other items when it has already been sold. I said, hey man I don't want to get in trouble, these things are reserved for some doctor according to this Work Order. Woody said, "I can open them very carefully and tehn reseal them later so well that no one will ever be able to tell they have been opened.

So, as you havce already guessed, the model 9 Marantz amps did get opened and hooked up to the four model 9's. As I remeber we finally settled on using the 8 ohm tap after comparing different taps for a while. The KLH model 9's are fairly high in impedance (around 12-20 ohms depending on frequency according to measurement later with Bill's little 'Z' meter that he rigged up later). The model 9 stats have input transformers with a radical primary to secondary ratio to provide a match for these internally around 50K ohm electrostatic panels.
Remember though, these early stats were rated at 16 ohms and we 2 per channel in parallel.

Later Woody took one of the stats apart and we found 4 panels in each side. four in front and four in the rear. These speakers radiate both front and back and should be placed at least 3 to 5 fett from the nearest wall behind them. Actually Woody's placement for the four had them well out into the room at around 7 or 8 feet from the wall behind them. Woody went and pulled an extra pair of AR-3 bookshelf speakers out to run in parallel with the two that were already in the sound room and then the real comparisons began. The AR-3's were running on the McIntosh 275 most of the time but at one point we ran them on the Marantz model 9's in order to determine if the amp was playing any part in the huge difference we were hearing. The four AR-3's were, of course capable of reaching down at least one full octave below what the 'stat's' were doing which was pretty much limited to a 55 HZ low end limit even in the far back of the room where Woody tried them briefly with one pair sort of closer to the corners (didn't help the low end...in fact I thought the overall imaging was worse so we moved them back to the other side of the room in front of the K-horns again).

The low mid range on the AR-3's did have a slight hint of the 'boxy' sort of sound so typical of Acoustic Suspension systems. (later HP tests with B&K mic confirmed that the AR-3's had a 6 db deep hole in the curve at 120HZ but only about 1/5 of an octave wide so this is a relatively small effect. The upper mid range on the array of AR's was smooth and pleasing but there were some noticeable 'lobing' effects that you could notice if you stood at various positions around 6 feet away.

Granted, this is probably not a good overall listening position anyway but this was a critical comparison and we were trying to find out all that we could. The high end on the AR-3's was a little rougher and of course very limited in high end response compared to the Model 9 electrostats. The overall imaging on the KLH electrostats was superb with a 'seamless' really large image. We tried switching the model 9 Marantz amps over to triode mode and the AR's still seemed to work well. The electrostats had a slightly more 'airy' light sound in the mid range but were so severely underpowered in triode mode that we had to really watch the gain control on the Marantz model 7c preamp because the amps were very easy to drive into really mushy and raucous clipping. After all we are dealing with a 40 watt per channel setup in this mode with the lowest efficiency speaker system I had ever seen.

The high frequency range was easily the cleanest most delicate I had ever heard with well over an octave of added high end response above the AR-3's (later HP and B&K equipment tests confirnmed that the high end is extremely extended well beyond audibility on the stats (30KHZ +) Yes...we did compare a single pair of KLH 9's to the pair of Quad electrostats we already had. The Quads were very nice with bronze color metallic perforated grill and were shaped like (and looked like) the back seat on a 1930 Ford Model A car with a slight convex curve upward. The quads were only half as high but about twice as wide. The quads had low end limited to around 80-90 HZ but other wise sounded very nice.
(Yes we had tried these before with the Marantz 18 db/octave electronic Xovers in a bi amp configuration with AR-1W woofers. Too bad we didn't ahve that setup
to compare because I remember it being a very impressive but strange lookiong rig).

The quads were hooked up to a pair of 10 watt Quad mono tube amps. They played ever so slightly lower in level (1.5 db lower we later found) than the Model 9's on the Marantz 9 amp. You would expect the difference to be much greater than that. The Quad 'stats' did seem to be more reliable but we never sold very many even though they were far lower in price about 350.00 less per pair than the KLH 9's were. The strange and old appearance did seem to limit its appeal (and market).

On the KLH 9's, one lady customer that bought a pair later had laughed and told us that she had put the stats in a back room because her dog stayed in the living room by the big windows and would howl loudly if she played the model 9's in there. She said that it never did that on her old Bozaks. Over the years I have heard all sorts of stories about the KLH power supply that provided the 600 plus volts anode voltage for the aluminized mylar film stretched over front and back frames (it appears that these sort of got sickly with lower voltage after 6 or seven years of continuous use). The high humidity found down in coastal Texas near the Gulf of Mexico seems to really take its toll on the panels also with later complaints from customers living near the water about snapping and popping sounds, (like a garden bug zapper). We never had any complaints from customers about mosquitos though. I wonder if there was a connection?