Stax ELS-F81 thinking of side-grading

[faust3d]

Shipping would be a problem unless you are moving to NYC!

[Dusty Chalk]

Nice!

Glad they were better than expected, and that you ignored my advice and took the gamble.

[n3rdling]

Wow very nice! They look to be in good condition to boot Looking at that third picture, is it actually possible to tilt the panels?

[faust3d]

perhaps NYC could move here?

I wish you could pick them up. After that many years it would be cool to find a good home for them. For now I might do a huge comparative listening session. Should be a lot of fun.

Wow very nice! They look to be in good condition to boot Looking at that third picture, is it actually possible to tilt the panels?

Yeah, up to 15 degrees upwards.

[Torpedo]

Dmitri, they look gorgeous. If you like them better than the Apogees, I bet they sound great. That's a cool piece of planar history

[Duggeh]

The Stax look awesome dear boy. Moar pairs of speakers is also awesome.

If you ever want to get the glass in your windows to rattle Soundlabs are the way forward for a 5th pair.

[schorsch]

I have a pair of these beasts:-)) too

Even with the DA80M (old class a) you've not enough power. Look for DA100M or best DMA x2. Or someth#ing like a Accuphase p600 ...

You need really power to drive these.

But then you are in heaven:-))

To my knowledge there is no speaker out there with which can compare in the mids ans soundstage.

Regards Georg

[Voltron]

Those Staxen speakers look awesome! Enjoy!

[guzziguy]

if i move in with my late GF next year, as is planned, i'll need a second rig anyway.

I'll bet having a dead girlfriend is a lot less complicated than having a live one.

[faust3d]

The Stax look awesome dear boy. Moar pairs of speakers is also awesome.

If you ever want to get the glass in your windows to rattle Soundlabs are the way forward for a 5th pair.

I had a chance to get BIG SoundLabs, don't remember the model, for like 2K. But when I measured them they would not fin in my stairway, so I unless I would bring them in trough the window I was shit out of luck. I wish I had a house.

[audiosceptic]

When I had my Quad ESL 63's repaired at Electrostatic Solutions in Kansas City, Kent had a pair of Stax F-81's among all the Quads he owned or was repairing. When I asked him about them he stated they were the only speaker he thought were as good or better than the Quads. I didn't get a chance to listen to them but I am always looking out for a pair.

[faust3d]

Changed placement and had them playing for some time now and I am amazed how resolving these speakers are. I never heard anything with this level of micro details short of Ergo AMT or SR-007, forget about all of the speakers that I heard, non of them come close I am talking about headphone levels of details here. Apogees are resolving, Quad 68 are resolving, ML speakers have a very good transient response and detalization, Magneplanar have lots of low lever details but these things are like a microscope all this while having the most lovely midrange ever. This is with an amp that is not that best amp form them by a long shot. I need to get Plinius SA100 or some similar sweet Class A monster in this ASAP

[n3rdling]

Threshold 4000 Amplifier - For Sale | AudiogoN

[deepak]

How do those amps sound, have semiconductors come a long way in 30 years that modern Class A/AB amps would sound better?

[luvdunhill]

How do those amps sound, have semiconductors come a long way in 30 years that modern Class A/AB amps would sound better?

that second question is easy, no. do some research on "lateral" versus "vertical" MOSFETs, in the context of audio.

[faust3d]

Played with positioning and found this works the best:

Plus now my apartment looks like a magazine advertisement from the 70's

[Dusty Chalk]

You found sepia works best? Nice!

[faust3d]

I really should get sepia colored glasses.

[robyatt]

The F81's you saw at Kent's may have been mine. I bought a pair from the reviewer jack English 2 or 3 years ago. I played them with a Luxman M6000 and they sounded great, but not better than my PK Quad 57 rebuilds (stock). I then, managed while changing a cable, to blow them up. I sent the transformers and scared electronics to Kent. He said they were done, no more, un-fixable. He did try to copy the trannies with a USA based manufacturer but they all blew up! Then luck struck! My friend Andrew Jones, (TAD), remembered that his friend at Technical Brain in Japan, went to school with Mr Suzuki of Stax. A few emails, and we got the original plans and specs from the very kind and gracious Mr Suzuki. Kent can tell the rest but after some expense and trial Kent was able to have the Transformers not only replicated to spec, but made to be more robust. I just got round, a year later, to sending the panels and frames back to Kent. He did his usual over the top fantastic restore and repair work on my Stax. They arrived last weekend.

I sat them down next to the Quads and hooked them up to my ASR Emitter I Exclusive Blue, Gold Board integrated. (the best electronics I have heard or owned). Initial reaction was they were better than the ones I sent away. The ASR shut down a few times, that appears to be the long time for the transformers to saturate. 24's hours later the sound levels are around 84db average, with over 100db peaks. They are about 2ft from the rear wall and close together with no real toe in. I sit real close. I actually turned the volume down last night!

They are not as all round perfect as the Quad 57's, BUT within a narrow volume range, and with limited dynamic swings sat up close-NO speaker approaches their transparency, detail, inner light, cohesiveness, and shear ability to disappear! My wife sat down in front of them and she has heard all my speakers, complained about many, but loves my 57's and OMA Mini's. Her words after 5 seconds-"WOW" then "the musicians are in the room".

I rushed home, last night to play them again, moved the 57's something I have never done, and was disappointed. Then as I sat and emailed as a distraction, my ears became calm and adjusted to the lower volume level, I was enthralled and captivated again. I sat for hours and listened to LP and server. Digital from the top of the line MSB stack never sound so good and LP colorations were starkly exposed, LP still as ever satisfying of course.

So far I can say they will not leave my house again. Kent restored a speaker many will never hear, but I can assure you just as I blew away people at the NY HiFi Show this April, by playing my 57's, as startling as that experience was for many, this is in yet another league. Limitations and caveats aside the Stax F81's are one of the top five speakers probably ever made, with the likes of Quad 57's and LS3/5A's, etc...

[spritzer]

Glad you and Kent got them working again. Winding electrostatic transformers is a bit of a black art and there are plenty of things to consider. Now you just need to find somebody to build a direct drive amp for both the both speakers...

[Mach3]

Very old thread, but anything is better than nothing.

 

Anyone got Kent's contact details?

I've got a F81 purely by accident, both speaker working but one of them doesn't play as loud. 

Pull them apart and did a panel swap, still same issue. Then check by placing a led light behind the panel.

Spotted 4-5 small holes in the mylar membrane on the lower two section of the panel.

Anyway one know anyone in the world that would have a spare working panel?

[spritzer]

I doubt anybody has a spare panel for these but Kent is at Electrostatic Solutions

[Mach3]

Thanks heaps got in touch with him.

Very nice and down to earth person to deal with if anyone needs their Quad or Stax ESL service.

Looks like I need to send him the panel to have them both restored to match.

 

Edited July 22, 2019 by Mach3

[spritzer]

I've only talked to him once but he seemed like the nicest guy.   

Makes sense to do both panels at the same time.  Might also be time for the bias supplies too. 

[Mach3]

Long overdue update.

I ended up sending my panels to Kent at Electrostatic Solutions 2 years ago.

Cost was very reasonable, Kent gave me detail instruction on how to put the panels back and connect everything back up.

I also took detail picture and notes as well before sending them off. It was about 3 weeks turn around.

 

Spoke to Kent on advice in regards to proper amp to power them, safety mod etc.

The stock safety circuit resistor 2W 12Ohm needs to be swapped with 10W 12Ohm to prevent the panels from arching.

Causing holes in the panel's membrane.

Tube amp are best to drive them due to the speaker impedance curve.

Kent mention he uses the ARC REF300 300 watts to drive his F81 and F83 (Basically 2x F81 stacked 3db louder lol)

He can achieve 98-100dB peaks before clipping about the limit of the F81 design.

I'm using a Primaluna Premium amp 8x KT100 which output about 100watts. I get about 92db peak.

The speaker are very touchy with placement. but are absolute divine once position correctly.

Can listen to them for hour with no fatigue what so ever.