Are you experiencing a measured roll-off, or do find the HF content insufficient for your listening tastes? I ask this question because high frequency response can be very difficult to accurately measure in real-world rooms, and such measurements almost always result in an apparent HF roll-off. And the larger the radiating surface, the more misleading the results can be. So, if you are basing this complaint solely on measured results, but find the speakers to be acceptable to your ears, then I suggest you put your measuring device away, sit back, and enjoy the music. I hate to sound crabby on this point, but I think a lot of audiophiles get themselves unnecessarily worried when they try to measure their systems, and suddenly find "something wrong".
However, if your ears are telling you that you have a sharp fall off above 5K, then we can discuss further.
Hi. I have just acquired a pair of Monitor 3. Previous owner had them in storage for the past 15 years. He fired up the amps before I had a chance to look at them. However he did not hook them up to the speakers. They were heavily caked under the covers which I brushed off very well. I have been listening to them for a few days without issue. Initially the attenuators were very scratchy, the HF pots perfectly quiet. They are now also quiet after vigorously moving them back and forth a few different times. They play great. But I'm wondering how safe it is to be using them after such a long time. I get that having them checked out is the prudent thing to do. Is there potential for serious damage if something blows in the amps? I've left them plugged in 24/7 for 4 days now. They seem fine.
Also, why are the panels arranged in a convex array rather than concave? It seems to me that in a concave arrangement, they could be focused(adjustable) for distance, but more importantly, beaming issues would be eliminated. Horizontal dispersion would be similar to a cone?
Could additional panels be mounted facing backward for a dipole arrangement? Would the amps be able to handle the additional load?
Could additional panels be mounted facing backward for a dipole arrangement? Would the amps be able to handle the additional load?
The fact that the amps were in storage for 15 years is probably the only reason that they are working now, as it's rare for the amps not to need some kind of service every so often. New tubes, if nothing else. Nevertheless, capacitors and such do age just sitting there, so it might be wise to have them gone over by a person who is familiar with this rather unusual product. I suggest you contact Mike Savuto. The last email I have for him is acoustataalic@gmail.com. Hope that still works.
A failure in the amp will not harm the panels, and only rarely will cause collateral damage in other parts of the amp.
If the panels were arranged as a concave curve towards the listener, the "sweet spot" would be unacceptably narrow...like millimeters wide. In other words, beaminess would increase, not decrease. Note that all ESL's that have a physical curve or segmented arc is shaped so that it is convex towards the listener...and for good reason.
The servocharge amp can drive three or four panels. But clearly you are not understanding that the panels already radiate from both front and rear, and therefore ARE dipoles.
Thank you. I do get that they radiate in both directions but because of the felt backing, sound is a bit diffuse in the back. I just happen to have a second set of panels.
Greetings Acoustatanswerman,
I'm a newbie here and have some questions and need some advice about my Acoustats. Near as I can tell I have a pair of Model 6's with 4 of the MK - 121 -2A Interfaces serial numbers 30 280 1 thru 4. They appear to never have been modified.
I have had these speakers for 25+ years and used them daily for the first 5-6 years. At the time I lived on the Coast in Washington State and crated them up and moved them with me to the US Virgin Islands 19 years ago. They have been crated in a dry storage container since and I'm now interested in refurbishing them and using them here. I have a fairly big space 28' x 28' x 17' so they'll work well in the room but I probably need more Amp power than I had before not sure how much power I need to run these properly?
The interfaces MK 121-2A are pretty clean but I would like them gone through with the latest upgrades. Not sure who is doing this type of work now? I need to replace the grill covers but that's not too difficult.
I'd like to get your opinion on using these speakers where I live as I'm on a small Island with an onshore prevailing wind and lots of salt mist. I'm concerned about rust or corrosion especially on the grids as I'm not sure what they were made of. I don't want to ruin these speakers by exposing them to this environment if it's going to damage them. Please let me know what your thoughts are. Thanks Mark
I'm a newbie here and have some questions and need some advice about my Acoustats. Near as I can tell I have a pair of Model 6's with 4 of the MK - 121 -2A Interfaces serial numbers 30 280 1 thru 4. They appear to never have been modified.
I have had these speakers for 25+ years and used them daily for the first 5-6 years. At the time I lived on the Coast in Washington State and crated them up and moved them with me to the US Virgin Islands 19 years ago. They have been crated in a dry storage container since and I'm now interested in refurbishing them and using them here. I have a fairly big space 28' x 28' x 17' so they'll work well in the room but I probably need more Amp power than I had before not sure how much power I need to run these properly?
The interfaces MK 121-2A are pretty clean but I would like them gone through with the latest upgrades. Not sure who is doing this type of work now? I need to replace the grill covers but that's not too difficult.
I'd like to get your opinion on using these speakers where I live as I'm on a small Island with an onshore prevailing wind and lots of salt mist. I'm concerned about rust or corrosion especially on the grids as I'm not sure what they were made of. I don't want to ruin these speakers by exposing them to this environment if it's going to damage them. Please let me know what your thoughts are. Thanks Mark
Wow, model 6's and in the Caribbean - that's cool!
You'll need two identical amps for each speaker.
You need either ss amps that can play with 2 ohm
load or tube.
I have both and use ss ( nad 208thx) when I'm going to listen for just 15
Minutes and don't want to warm up the tube amp
(Jolida 1000).
You'll need two identical amps for each speaker.
You need either ss amps that can play with 2 ohm
load or tube.
I have both and use ss ( nad 208thx) when I'm going to listen for just 15
Minutes and don't want to warm up the tube amp
(Jolida 1000).
I think I'll probably go with SS Amps don't think the tube amps will live in the Caribbean environment. Thinking about something like 2ea mark Levinson 532's or similar, looking for suggestions. Got ahold of Roy and we're talking about upgrading the interfaces. Has anyone remote mounted the interfaces, they aren't part of the speaker support on these speakers and would be less obtrusive in separate enclosures, I realize that we're dealing with high voltage and small current but it seems possible?
In regards to the potential salt-spray environment, I have heard no reports of long-term damage to the panels, and I have communicated with several owners who live in similar environments. The primary structure of the panels are plastic, the stators are wires with thick PVC insulation, and the diaphragm is Mylar. So there's very little that can corrode. I would suggest the continued use of a similar-to-original grille cloth, which is a double-knit polyester.
It seems you've already made contact with Roy Esposito, who is the only person I know of who does any sort of Acoustat speaker repairs (I have no affiliation with him). I assume he already informed you that he prefers not to ship to addresses outside the US, so you'd probably need to work through an intermediary in the mainland US. For the benefit of others, he can be reached at soundslikenew@prodigy.net.
It is possible to mount the interfaces remotely from the panels, and it has been done before. The key is finding a suitable high voltage wire, which needs to be rated for 10-kV. You can find such wire at major electronics suppliers, but don't be expecting to find anything described as "audiophile grade". Still - I think it best not to mount them too far away, maybe no more than 6-10 feet.
But when you say the interfaces are not part of the speaker support - isn't there a steel strap that extends from the side of the panel frame to the MK-121-2A interface box? You would need to somehow replace that function.
You are correct there are 2 straps on each panel that went to the interfaces but I can easily fabricate some new longer ones from stainless steel. I'm not sure about splicing the cables to remote mount the interfaces, I'm more concerned about the insulation than the mechanical part of the splice but I guess I'll have to figure it out. They won't be over 10' so that should work out alright. Roy has a different email address for the last couple of years now Roy A. Esposito acoustat.service.usa@gmail.com I have a lake house in SC and so can arrange transport through that address to satisfy his shipping needs. Hope it all works out alright. Thanks
Don't see why the area you live would be bad for tubes.
The most important property in an amp is the ability to work into low impedance. That ML amp doesn't have a rating for 2 ohms,so I'd assume it won't work.
If you want a new sand amp and one that will work with your speakers, Innersound makes amps designed to work with esl. If you want older amps, Transnova, Hafler are names that come up. When I wanted another sand amp, I saw how NAD rated the 208thx 900w into 1ohm load and thought "Yup, she'll work!".
Other names that have come up are Threshold and Meitner.
The most important property in an amp is the ability to work into low impedance. That ML amp doesn't have a rating for 2 ohms,so I'd assume it won't work.
If you want a new sand amp and one that will work with your speakers, Innersound makes amps designed to work with esl. If you want older amps, Transnova, Hafler are names that come up. When I wanted another sand amp, I saw how NAD rated the 208thx 900w into 1ohm load and thought "Yup, she'll work!".
Other names that have come up are Threshold and Meitner.
I have a pr of Acoustat 6s setup here ..with the 4ea MK121-a interfaces.....every 2 added panels seems to give 3 more db output...I have found that ea 3 or 4 panels do need there own bias...you cant run all 6-8 panels off one Acoustat bias....
But for about 6 months ... I have been running 6 panels off one MK 121 interface transfourms.....work an sound great....it seems easier on the amp with 6 panels then driving my 2+2s.....it dose have a little better bass with all 4 interfaces two amps... but I like the sound of the one interface & one amp channel for 6 panels....all the parts in the MK121 interfaces run cooler....I watch the interfaces res, parts closely....
Well be adding 4 more panels to have a pr of Acoustat 8s soon.....what a sound......nothing like it so far in my life
I say long live Acoustat
But for about 6 months ... I have been running 6 panels off one MK 121 interface transfourms.....work an sound great....it seems easier on the amp with 6 panels then driving my 2+2s.....it dose have a little better bass with all 4 interfaces two amps... but I like the sound of the one interface & one amp channel for 6 panels....all the parts in the MK121 interfaces run cooler....I watch the interfaces res, parts closely....
Well be adding 4 more panels to have a pr of Acoustat 8s soon.....what a sound......nothing like it so far in my life
I say long live Acoustat
There are articles on the net discussing how the freq response of ESL, when used with ss amps, gets irregular. One cited a 5 db drop in bass.
I have a switch box to go from my ss amp to my tube amp and I notice
Less bass with the ss amp. The difference is about equal to using or not using
a loudness circuit .
Let some tubes light up the 6's!
I have a switch box to go from my ss amp to my tube amp and I notice
Less bass with the ss amp. The difference is about equal to using or not using
a loudness circuit .
Let some tubes light up the 6's!
I'm still looking for amp's the Krell KSA's and Hafler Trans-novas seem like good candidates so far. My concern with tube amps here in the Caribbean is two fold, The first is that Tubes are plugs and sockets and in this high humidity, high salt environment this is food for corrosion. Think the beach houses in South Florida x 2. We coat all of our plugs, wire terminals, Etc. with dielectric silicone grease to help ward off the corrosion monster, I don't want to disassemble amps and try to coat all of the plugs and sockets and am not sure how the silicone grease would hold up to the heat. The second problem from this location is getting service when I need it. We are a part of the US but are treated as a foreign country by many and shipping to and from here is very expensive! I feel that to find two identical amps that are going to be able to be serviced by a factory qualified facility is going to be very difficult. I've looked at the Sanders amps but there's very little in the way of reviews or other info on them. I'm still open to suggestions maybe someone has experience that will open my mind to tubes? Thanks
I think a tube amp would be a heck of a lot easier to service than a ss amp.
For example , my nad 208 is a very complicated amp and the 65 year old tech
told me more than once.
My Jolida tube amp? A tube died, took ten minutes to replace and bias up .
There is a pronounced difference in how they sound, if you ever come to the
Mainland , maybe you could hear it.
Right now, I'm listening with my ss amp, don't want to warm up the tubes.
I like the tubes but I won't say that ss is awful or ear splitting , just like the magic they give vocals, plus better low end. Hear both and decide for your self.
In a perfect world where I owned 6's, I'd probably get two hafler xl 280's to use when I want to listen for less than 30 minutes, then a pair of some 100w+ tube amps for those nights I work through some good IPA beer.
For example , my nad 208 is a very complicated amp and the 65 year old tech
told me more than once.
My Jolida tube amp? A tube died, took ten minutes to replace and bias up .
There is a pronounced difference in how they sound, if you ever come to the
Mainland , maybe you could hear it.
Right now, I'm listening with my ss amp, don't want to warm up the tubes.
I like the tubes but I won't say that ss is awful or ear splitting , just like the magic they give vocals, plus better low end. Hear both and decide for your self.
In a perfect world where I owned 6's, I'd probably get two hafler xl 280's to use when I want to listen for less than 30 minutes, then a pair of some 100w+ tube amps for those nights I work through some good IPA beer.
One listen to a direct drive OTL and it'll definitely be a revelation. IMO, interfaces with ESLs sound thin somehow. Like they're being held back. But my Monitor 3s are all in with a presence that is uncanny in it's ability to convince you. No comparison whatsoever with anything else I've ever heard in the past 40 years. There are a couple of manufacturers that make DD OTLs for ESLs. However the OTLs do need periodic maintenance. Once you hear them, you'll be glad you got them, though. Roy may be a source. The Acoustat OTLs are fabulous.
Acoustat servo amplifiers?
Has anyone compared the tubed direct drive Acoustat servo amplifiers to the usual transformer drive?
Acoustat upgraded and modified servo amplifiers | eBay
Has anyone compared the tubed direct drive Acoustat servo amplifiers to the usual transformer drive?
Acoustat upgraded and modified servo amplifiers | eBay