ESS speakers synergise with valves?

I recently bought a pair of old ESS PS5C speakers.These use a small Heil Ribbon,a ten inch mid woofer and a rear mounted ten inch passive radiator.
I started out using some of my SS amps amps with these and whilst I could hear that they were doing some things really well,felt that a hollow and slightly coarse midrange detracted from their overall sound.They had a typical 'west coast" sound,although infinitely better sounding than their JBL contemporaries.
To combat this I doped the woofer with liquid silicone.This is often a subtle but very effective way of reducing paper cone colourations.
The next day I changed amps to 23 watt EL34 Trimax monoblocks,never really expecting them to drive them properly.But was I ever wrong!
The sound from this combination is simply amazing.These are now incredibly neutral sounding speakers,with fantastic bass,clarity and imaging.
Anybody who has been using valve amps for a while comes to know that they very rarely achieve their potential with mainstream speakers.So when we discover one that is the exception to the rule we need to announce it.These ESS may not to be to everyones liking-they are quite analytical,but on balance I think they are still a real find for tube lovers.With a 300b SET amp they could really be something.
Just to confirm the ease of driving I have also run them with a Tripath 10 watt class T amp.Not as good as the valves but still drives them quite loud before clipping and sounds better than SS.

Has anyone else discovered these?
I have an old pair of ESS speakers that I have had since 1971 I re did the surround on the woofer a few years ago and they are still playing every day. These speakers really sound good whith a Bottlehead foreplay tube pre amp and a solid state amp.
Yes I too, Have a pair of ESS AMT (Model 5) and just this last week pulled them out of the garage to find that all surrounds on the 10" woofers and 10" passive radiators were I bought two new OME 10" woofers with 125 RMS handling and bought two new OME passive radiators and of course I had to rubber cement them to the existing octagon shaped aluminum frame and them remount them in the back of the cabinets... ESS put alot of science into their sound from what I can hear...loud, quiet...either way they are crystal clear and very responsive no matter how much power they are running on...20, 30 or even 90 watts...these have got to have the biggest boom for the smallest power consumption over all and usually that is the goal when a passive radiator is present in the cabinet(setup)......Now some trivia questions that I would like answers to: What year did the ESS Performance Series (Model 5) come out? How much money did a pair of these speakers cost when they first hit the shelves? Was ESS top-of-the-line for its time? Why did ESS shut down (go out of business)-(in Southern California?) Thank for for you interest in ESS VINTAGE AUDIO as much as I am -- Dave
I have 35+ year old PS-8A's which I've been meaning to revitalize again. The woofers are shot but the passive radiators had been replaced awhile back. The Heil air motion transformers look OK but we'll see (why shouldn't they be?) I have a Fischer 500c receiver that I'd like to run into them that I'm thinking would probably be an interesting match. The original Technics 45 watt per channel receiver which I bought new in 1972 and used with them is still in use everyday at my mother's [no servicing ever done to it]. Can anyone tell me specifically where I can get these woofers replaced ? I know there was a place where you can send the baskets and they rebuild the rest of it again, but I lost that site. Any ideas? These were definitely ahead of their time speakers "Sound as clear as light" was a fitting moniker. Regards
ATTN: LISSNR - - Yes!! As you read above, I just rebuilt my ESS Tempest LS-5's with two new 10" woofers and two new 10" passive radiators... I was chatting with Eric from Orange County Speaker (and repair) Inc. and I asked him what woofer would best replace and be most compatible with the existing ESS enclosure and passive radiator system...he gave me a link within the Orange County Speaker website and he said they carry, without a doubt, the best match woofer that complies with the Vintage ESS woofer. These have a paper cone, foam surround, 8 ohm, 2 inch voice coil, 175 watts RMS and a frequency response of 23hz - 3.5khz...and from what I can tell they even look like the original ESS Tempest Woofers...the brand name of these are Eminence for a well worth cost of $69.95 each. The website for Orange County Speaker is: and the keyword is 10 inch Eminence 1040SF Woofer... Ok, there's that info, now onto woofer surround (foam) repair kits and replacement passive radiators...Orange County Speaker also sells those as well. Hope this helps Lissnr... Let me know! And yes, mine now also, finally have--"Sound As Clear As Light" -dave
Thanks Dave, I've now put that site on my favorites list and I'll be picking up those woofers soon. I may have to call to speak with them about the passive radiators though. Thanks for the insight!
No Problem!...Didn't the PS-8a's have 8inch woofers? I cant remember...If so, I hope OCS also has the Eminense woofers in that size as well...What kind (disk or cone) and size of Passive Radiators do your ESS's have and what concerns have you come across with them? Hey, just for kicks, check this site out...just scroll down until you come across the PS-8a'S...Good luck on reading any of it though...p.s. Are ESS's being manufactured in Germany or something?? Here's the link:
Best Regards, --dave
Hi Dave, Yes, Mine are the 8" woofers and they do have the Eminense woofers in that size. My passive radiators are 10" across (only about 8" or so of actual driver size). My only concern with them was whether the surrounds are drying out at all or something but I know they've been replaced sometime ago so I'll leave them as they are when I get the new woofers and see how they do.I don't know if ESS are being made anywhere or not? Germany you think? Interesting. BTW I appreciated your visit to my system and wrote you back there. I'm going to check out that above link. Thanks Dave. Grant
Yes Dave, The 8" Eminense woofers are on that OCS site, the 10" passive radiators I'm going to leave "as is" for now because I had replaced those previously (Only concern was whether the surrounds/edges were deteriorating or not, but they seem OK). That link does bring you to ESS's avail. in Germany or wherever that is,it looks like?! The specs are the same as mine (6 ohm, and efficiency, etc, I believe), but the Heil Air Motion Transformers are mounted vertically on mine, not horizontally, and the cabinets are taller in the new ones. Very interesting!
Oskar Heil, who held the patent, or one of the patents for the FET (field effect transistor from the 1920s) invented the air motion transformer. It was a genuine departure from the standard loudspeaker that continues today. ESS was owned by three fellows in California, good guys who wanted to be very successful. I believe they moved too quickly to gain sales volume and their reputation and cash flow suffered. The AMT, air motion transformer, was not perfected as a loudspeaker. Part of the problem was the limits of technology at the time that caused some response peaks. The enclosures that included the air motion transformer speaker systems tended to be slapped together and the other drivers used were cheap. I don't know the details but the company simply failed to compete and disappeared. One of the owners was Phil Cohelo, who may have been a brother of the former California legislator. Another was Gary Hudson. The third was a college professor who reminded me of Gilbert Roland, the movie actor. It was a treat meeting Dr. Heil, who looked a lot like Einstein's pictures and was a genuine, brilliant scientist. It's a shame the company failed. They went for the mass market and failed. The air motinon transformer has been improved by current owners of the ESS name and is included in very expensive loudspeakers.
Hermanadolph-Looking at the line up of ESS speakers from the first, to the last models, one can easily see they weren't moving too fast.
Trying to get Heil technology into the lower end of the audio spectrum has little to do why they falied.
Yeah, sure they wren't buliding $11,000 speakers with a corespondingly high profit margin, but that too has little to do with good business.
Over extension, and failing to reinvest in their company was the main reason why they failed.
Take a look at the AMT 3, easily one of the finest Heil speakers out there, carefully designed 3 way, with quality drivers. Yes, they used cheap caps in the crossovers, lots of manufactors did in the 70's.
I would put my rebuilt set (w/rebuilt crossovers) up against any of the German made models.
Putting a $300 woofer and 'designer caps' doesn't guarantee good sound-engineering does.
They synergise very well. I have custom built speakers that utilize the largest tweeter, the one they used in the 2 way originaly. I also have a tube pre and power. the crossover uses Jentsen caps. I am more than satisfied. The speakers are three way. The problem in the 2 way original speakers was the tone and timbre in the mid range; it was not as mellow as a cello.