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?
128x128jtgofish
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.