The Hub: Acoustat X: 'stats with tubes!


While some companies ease their way into the public eye, others leap out with a big, bold statement product. Think of the Wilson WAMM, the Avantgarde Trio. In their less extroverted way, the Acoustat X (seen here) was no less audacious. The level of technological density rivals a late-model S-class Benz, only less prone to failure.

Last time out, I mentioned a visit to Frank Van Alstine's basement showroom, 'way back in 1978. Along with the Connoisseur turntable directly connected to earth ("earth", as in DIRT: the 'table was on a column Frank had constructed, anchored right through the floor to the cold, cold Minnesota soil), there were Acoustat Xs. I think Frank had tweaked the amps, just as he had tweaked everything else. I don't recall any details other than Frank's comment, "they (the Acoustats) make everything else sound like they're broken."

And so they did. Even at that point in my young life I was no stranger to 'stats, having heard QUADs, KLH 9s, the boxy, almost-forgotten Koss, hybrids from Infinity, ESS, JansZen and RTR, and an oldie which resembles our subject, even in name: the Acoustech X. As the audio village is a very small one indeed, it's not surprising how much inbreeding there was in that group: the KLH 9, Acoustech X and the Koss Model One were the work of Arthur Janszen, and the RTR elements were a descendant of the Janszen add-ons. More detailed history of the ESL can be read here, courtesy of MartinLogan.

But I digress, as always. Those Acoustats in Frank's basement were punchier and less-fragile-sounding than any of those other 'stats I'd heard. Their drive and dynamism were reminiscent of big Altecs or JBLs, with greater resolution and less coloration. How'd they DO that?

Electrostatic speakers are by nature high-impedance devices. There are basically two ways to drive them: either have a step-down transformer so that conventional amplifiers can drive them (assuming said amps can handle a capacitive load of widely-varying impedance), or directly-drive the elements with a high-voltage amp. QUADs, KLH 9s, the Koss, and most modern electrostats follow the former path, while both the Acoustech and the Acoustat followed the latter (as did Harold Beveridge's speakers, with amps designed by Roger Modjeski).

Jim Strickland, President of Acoustat, worked for "Jeep" Harned, the founder of MCI, the well-known producer of recording and mixing consoles and pro tape transports. Strickland handled the design of the tape-tension and logic systems, developed the first autolocator system for pro consoles, and wrote a few papers on tape-transport issues, which were published by the AES. Strickland and Harned developed an electrostatic speaker (named after Harned), which was reviewed in the Summer, 1966, Stereophile. Oddly, the speaker was a two-way which included a built-in amp for the treble panels, but had a matching transformer for the bass, so separate amps had to be used.

The Harned electrostat foreshadowed the ski-slope design of the Acoustat X, but the X refined the earlier design and improved it in every parameter. In the Stereophile review of the Harned, JGH had noted a phasey, unreal quality to the sound, and a rolled-off high end. Neither criticism was ever made of the Acoustat X.

Strickland brought elements of his tape-handling experience to the X, and subsequent Acoustats: the diaphragm was formed of a special Mylar utilized by Ampex in the production of recording tape, and the method used for applying conductive graphite was derived from methods of oxide-application. Each electrostatic-element panel was constructed of a plastic grid (which looked suspiciously like the diffuser element of a commercial fluorescent light fixture), rather than the perforated metal commonly used; this, coupled with a glued-wire element, produced a panel claimed to be indestructible. You can see the production process at this link.

The X used three full-range panels arrayed in an arc to minimize the beaming characteristic of most 'stats. The panels were driven by a hybrid solid-state/tube amps, designated "Servo-Charge", and if the 300 or 400 volts commonly found in tube amps makes you nervous, you probably don't want to hear about the 5000 volts found in sections of the X's amps.

A few minutes spent Googling the X (sounds like a SoCal NoWave band from 1987, no?) will show that a cottage industry has been built around maintaining, restoring and tweaking them. You can find ex-Acoustat guys who can do pretty much whatever you want with Acoustat Xs; the panels do indeed tend to be indestructible, but the amps will probably require maintenance, as any 30-year-old amp probably will. Ironically, later transformer-coupled models of Acoustats can be fried: not the panels, but the transformers!

Acoustat went on to build a wide range of 'stats, and some excellent and innovative amps. As most know, the company was bought by Hafler, and merged into the Hafler/Rockford-Fosgate family. In the US the brand disappeared in the early '90's, and was moved to Italy. More recently the brand reappeared in China, complete with vintage logo, and still appears to build electrostatic speakers. We may not have seen the end of this brand yet.
audiogon_bill
Well I got lucky and purchased a very nicely refurbished pair of three panel X monitors, yesterday, two days before my birthday.
Happy birthday to me.
The amps were tweaked by Dan the Man of DTS, and the results are very good.The cabinets were refinished to a pristine condition by Mark.
My hat's off to both of you gentleman.
And Matt, I'll treat these with the care and respect that you would have given them.
I hope you can be re-united with a pair in the near future.

I can hear one of my long time audio buds now when he sees them the next time he visits.It will go something like this -"well, it's about time,I told you to buy a pair of these 35 years ago, think of all the money you could have saved".

Well that's what I'm telling myself, but seriously,in my large room they are a perfect fit,most speakers just can't fill the room with sound and need to be played at loud volumes and that's not how I like it.

But they will play loud, make no mistake.

How can I describe the sound?

In a word effortless.

I have a friend who has a system composed of all AA listed heavey hitters, and a sound(effortless) that I have always tried to emulate but have never duplicated it on my budget.

But, taking a step back in time with these old relics has narrowed the gap considerably.

I realize most younger audiophiles haven't a clue about what I'm raving about, but I was a hold out for many years and passed on the Acoustats of old, just because I felt that newer is better.So a lot of X monitors slipped thru my fingers.But not this time.I knew how good they can sound when set up properly,and given upscale power cords and conditioning and using front ends that are better today than back in the 1970's.Like my two friends who never parted ways with their Servo amped Aoustats.

In fact I doubt people who parted with these ever knew how good the design really was/is because of the inferior quality of a lot of front ends back then compared to what's available now.

Really,these dinosaurs retrofitted for today,are worthy of mention as "end of the line" in the search for an amp and speakers.

To better them with what is available new today, you would have to spend a great deal of money,and perhaps not be as pleased with the outcome.

For the folks with the non servo amped Acoustat's , even the ones with tweaked Medalian mods,you have never really heard how good these speakers are.

I know, because I used to own the Model 3 Medalian, and the magic is in the servo amped models.

Am I happy?
Oh yeah.
To the initial poster, I beleive I have the cottage pair from the pictures.

They sure do clean up well.
Had a pair modded by Ian Fung. Loved everything about them except for the "auto on/off feature"
Yes Ian used to mod them and he modded the CJ pre-amps at the time to match up with the X's.
I've wanted a pair of these ever since way back when my friends went to Ian's for the mods in the 80's.

Dan Santoni,DTS Audio does a fantastic mod to the servos.
Very fast and clean sounding, and eliminates the auto on feature.The tubes are still left in warm up mode,you just flip a toggle switch to power up or down.
Also he upgrades the brilliance control with a stepped resistor array and upgrades caps and resistors.

He isn't far from where Ian lived, just outside Hamilton.
Update, the Acoustats are sounding even better with my new naim cd player.

I have found a source for tubes for the amps ,enough to keep me running for a number of years, or until I run out of time.

Very happy I made the move to this set up, not that there was anything really wrong with my previous system.

This set up just sounds more real,dynamic and less strained,which makes for some very easy litening.

Detail retrieval is better than I remember when I had a pair of the 3 panels with medallian mods.

Compared to my other friends who have the servo Acoustats,I believe they may have a bit more bass, but with a heavey overhang that tends to blur some detail.

The sound from my speakers is very fast and detailed, with bottom end authority when it's there on the recording.

Some may think that they are bass shy, but that would imply that there's never any low bass.

There is low bass when it's on the recording,and only then do you realize how low these speakers can go.

My friends speakers seem to pump out mid bass all the time at the expense of detail,which some may find pleasing, but not to me.

So after about a month, the honeymoon isn't over yet.