I just have to asked...
If Blue is the positive as seen in the 121 Schematic ....
why is it called the positive if its the back panels wire....?
It like my Acoustat play louder out the back....
As always thanks for any an all info on Acoustats are any ESLs...
If Blue is the positive as seen in the 121 Schematic ....
why is it called the positive if its the back panels wire....?
It like my Acoustat play louder out the back....
As always thanks for any an all info on Acoustats are any ESLs...
Attachments
![932906-single-acoustat-9-wide-electrostatic-panel-from-monitor-4-vintage-speaker[1].jpg](/community/data/attachments/556/556788-8f9285d8348f340f2b0dc7de01e8f77e.jpg)
![acoustat[1].gif](/community/data/attachments/556/556791-8f9a62f46ad115a631e142282d806333.jpg)
The blue wire goes to the rear stator grid, correct. It is at positive phase (or in-phase with respect to the incoming audio signal), so that when the audio signal is positive-going, the positive electric field on the rear stator grid will oppose the positive electric field on the diaphragm, causing the diaphragm to move away from the rear stator, or towards the front of the speaker.
At the same time, the front stator is negative phase (or out-of-phase with respect to the incoming audio signal), and therefore the negative electric field on the front stator grid will attract the positive electric field on the diaphragm, causing the diaphragm to move towards the front stator, or towards the front of the speaker. Hence, the speaker preserves absolute polarity, where a positive-going input signal causes the diaphragm to move forward.
The opposite scenario happens when the audio signal is negative-going, causing the diaphragm to move towards the rear of the speaker. A simple push-pull system, whereby the diaphragm is always under equal driving force regardless of its position within the gap.
As to why your speakers "play louder out the back" I cannot fathom why that would be, unless caused by a defective interface or room acoustics.
I posted this question ....Because I know most, like over 98% of people never have seen were the blue wire goes on there Acoustat panels.....
For years have found the blue wire moved to the front, an white moved to the rear, on any ESL panel ,sound more like my vintage Apogee an Magnepan ,an even my old JBLs, it a richer fuller sound......well to me.
I have a like new pr of Martin Logan CLS panels that I have been running with a pair of Acoustat MK121 stock interfaces...the blue in front on them, is a nigh an day difference...
Know one I have found like the sound better with the blue in back on the CLSs
Andys dissection makes me feel that my choice is base only on the sound of my setup,an what I like....
No Damage can be done by doing the Switch...
All just one Acoustat owners findings....
For years have found the blue wire moved to the front, an white moved to the rear, on any ESL panel ,sound more like my vintage Apogee an Magnepan ,an even my old JBLs, it a richer fuller sound......well to me.
I have a like new pr of Martin Logan CLS panels that I have been running with a pair of Acoustat MK121 stock interfaces...the blue in front on them, is a nigh an day difference...
Know one I have found like the sound better with the blue in back on the CLSs
Andys dissection makes me feel that my choice is base only on the sound of my setup,an what I like....
No Damage can be done by doing the Switch...
All just one Acoustat owners findings....
Servo amp question here. One of my "new" servo amps has started to develop distortion on the letter "S" sound of female vocals and other such transients. Also, the speakers are completely out of phase now. This just happened over the past week. Is this characteristic of a bad tube? These amps have been nothing but one problem after another. I need some Analogue Associates servo amps. 
Servo amp question here. One of my "new" servo amps has started to develop distortion on the letter "S" sound of female vocals and other such transients. Also, the speakers are completely out of phase now. This just happened over the past week. Is this characteristic of a bad tube? These amps have been nothing but one problem after another. I need some Analogue Associates servo amps.
I won't attempt to diagnose the malfunction in such a complex circuit. Could be a lot of things. Analogue Associates also does straight repairs in addition to several levels of modifications. Some of Mike's mods are aimed at increasing the reliability of the unit. I suggest you contact him as your most-trusted source for advice and repair. Owning servo amps comes with an almost-certain cost to keep them running, and I don't mean just new tubes.
So you're saying you like to listen to your speakers out-of-absolute phase. That's okay if it's what you prefer. But a much easier way to "try" this change is to reverse the input wires on each speaker, which does not require disassembly of the speaker and potential exposure to high voltages. It accomplishes exactly the same thing.
Thanks for your info..Andy
On paper all these question you , have been glad too help us all understand, has always seamed right..all here are luck to have some like you....this has been said more than once...an I for one am glad to say ..an I have never meant any disrespect ...
Yes its Right...but to my ears it dose not sound the same..as changing the panels wires....
Go fig...
I do think the Brain-Ear-Room-Audio Equipment, is a tough thing get right for anyone..an it could be said I spend to much of my time doing Audio related things..an I get...there must be rules...at lest to start with...
On paper all these question you , have been glad too help us all understand, has always seamed right..all here are luck to have some like you....this has been said more than once...an I for one am glad to say ..an I have never meant any disrespect ...
Yes its Right...but to my ears it dose not sound the same..as changing the panels wires....
Go fig...
I do think the Brain-Ear-Room-Audio Equipment, is a tough thing get right for anyone..an it could be said I spend to much of my time doing Audio related things..an I get...there must be rules...at lest to start with...
Glad to hear that help is still available for Acoustat from Acoustat Answer man. I have an old Spectra 11 that I bought new in 1989 or 1990. That was my first electrostat. It still works but I have not powered it up in 3 years, ever since I got a used ML monolith III (at a good price) to replace the Acoustat. Anyway, I usually listen to minimonitors or 3 inch full range speakers in my bedroom.
I have never tried to retension the mylar film or tweeked it. I once called the helpline because the sound seemed unbalanced and Acoustat sent me a pair of interfaces, which seemed to have resolved the issue. The Acoustat panels are supposedly indestructible.
I have never tried to retension the mylar film or tweeked it. I once called the helpline because the sound seemed unbalanced and Acoustat sent me a pair of interfaces, which seemed to have resolved the issue. The Acoustat panels are supposedly indestructible.
Spectra 4400 schematics were posted a few pages back:
Acoustat-Answer-Man-here-Post#1610
AAM can confirm, but I believe the circuit for the Spectra 44 and 4400 are identical.
Acoustat-Answer-Man-here-Post#1610
AAM can confirm, but I believe the circuit for the Spectra 44 and 4400 are identical.
Yes, the schematic shown serves the Spectra 44/4400/66/6600. Only the bass transformer taps change depending on whether it's a 4-panel or 6-panel system, as described in the schematic's notes.
This is no surprise at all, as most conventional speakers are more sensitive than ESL's. And if Acoustat (or any other ESL manufacturer) could have made their speakers more efficient, they certainly would have. Now that being said, it is possible to boost the sensitivity a little bit by increasing the bias voltage, but 1) I am not an advocate of doing so; and 2) unless you have the proper high voltage measuring equipment, it is best left alone.
I know very little about surround sound systems (being a two-channel-only guy), but I would imagine the associated processor/amplifiers would have some means of adjusting the level between front/sides/rear, in the anticipation that most users won't have perfectly matched speakers in those positions, and would therefore need some way to compensate for speakers of different efficiencies.
Hello all, I'm new to the forum and a proud new owner of a pair of Acoustat Model 3's. Best sounding speakers I've ever heard. I searched for a pair that was in mint condition for a few years. Once they were delivered I hooked them up and immediately sold my Martin Logan Motion 40's (which were also great speakers). Thank you AAM for creating this thread!
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Howdy; My name is Brad and I am not an audiophile. I spent much time in the early seventies hanging out in Stereo shops around Ann Arbor Mi.
I'm just now able to buy some of the things I could only dream of back then.
I've had the same pair of Infinity Qb's since 1976.
I am a Pink Floyd addict. That and big band. Buddy Rich , Gene Krupa ,etc make me happy.
Anyhow, this pair of speakers is fairly close to me. ( 150 miles ) which is next door around here.
I'd appreciate it if AAM or other experts could take a quick look & advise if they look decent & if with the right amp/source do a good job with my music?
Would be my first electrostats.
But I did enjoy the 'Wall of Sound' demos back in 73!
Thank you, Brad
Acoustat Sprectra II | eBay
I'm just now able to buy some of the things I could only dream of back then.
I've had the same pair of Infinity Qb's since 1976.
I am a Pink Floyd addict. That and big band. Buddy Rich , Gene Krupa ,etc make me happy.
Anyhow, this pair of speakers is fairly close to me. ( 150 miles ) which is next door around here.
I'd appreciate it if AAM or other experts could take a quick look & advise if they look decent & if with the right amp/source do a good job with my music?
Would be my first electrostats.
But I did enjoy the 'Wall of Sound' demos back in 73!
Thank you, Brad
Acoustat Sprectra II | eBay