The 208 is different from other nad amps,it was their best. It screamed for stats.
It is a dual rail high voltage amp that laughed at low impedance. It was rated at 900w into 2ohm load and has 5db of headroom. The amp also is thx certified.
It also is their last amp made in England, not China ( if that matters).
They don't come up for sale very often, I've only seen one come up on eBay in the last two years and it looked like it fell off a truck.
I am aware that some Acoustat owners operate their speakers without the felt blocks, and prefer it that way. That's okay. But I would remiss as the AcoustatAnswerMan if I did not mention the lack of felt as a possible source of trouble in this situation. I did not mean to imply that a lack of felt WOULD be a source of trouble.
Yes the 208.....I have owned the Amp...an you are right it of the older type NADs I have had....glad you like it....
I just never caired for there sound....Like the Carver TFM amps I sold in the 80-90 ......But the SunFire....I have owened sound great..
An I for one don't like the sound of Bryston.....But others think there great..
Trans•nova amps are just a fluk .....for minny years I had heard there sound an drive was special.....an for $100. a amp....there a lot to like...hehe
An as for the Acoustats panels Pades...Thay went for me becase I was looking for a better topend....you know like running the panels with out the Spandx cover...
My test for speaker cloth......is put it over your head.... an if you think you could live that way use it!.....not saying it dose not look good......but you know the fool i am..... all about the sound .....hehe...or Hoho
I just never caired for there sound....Like the Carver TFM amps I sold in the 80-90 ......But the SunFire....I have owened sound great..
An I for one don't like the sound of Bryston.....But others think there great..
Trans•nova amps are just a fluk .....for minny years I had heard there sound an drive was special.....an for $100. a amp....there a lot to like...hehe
An as for the Acoustats panels Pades...Thay went for me becase I was looking for a better topend....you know like running the panels with out the Spandx cover...
My test for speaker cloth......is put it over your head.... an if you think you could live that way use it!.....not saying it dose not look good......but you know the fool i am..... all about the sound .....hehe...or Hoho
A hair dryer is unlikely to have enough heat output, so use an industrial heat gun. Hold the nozzle at least a few inches away from the surface of the louver structure, and keep it moving continuously, covering the entire diaphragm surface. The idea is to slowly bring up the temperature of the entire diaphragm. And in case it's not obvious, this must be done with the grille sock removed and the speaker fully discharged.
I would suggest you practice on a piece a mylar first to get the feel of how the mylar reacts to heat. I've never had to do this with any of my acoustat panels yet, (knock on wood) I wonder how much the louvers can take, cause plastic does expand and contract as well, maybe it's just paranoia on my part.
Hi i had never heard of acoustat till i saw a pair of spectra 11 on ebay i purchased them on a whim .i soon realised that they are addictive and i soon wanted more i searched the web but found them impossible to buy only for sale in the us but no one will post. i have managed to get panels and interfaces and hope to build a set of 2+2 what i need know is can i use the ultrasonic power supply to change my mk121 2a interface fromusa 110v to uk220 v which would improve on original and save using transformers killing two birds with one stone?
I second the suggestion of practicing on scrap Mylar before turning a heat gun on your Acoustats.
Concerning the polystyrene louvers and heat:
Target temp for heat shrinking Mylar is 150 °C - 170 °C
The melting point for Mylar is 250 °C, melting point for polystyrene is similar.
However, the glass transition temp for polystyrene is only 100 °C, so some deformation could certainly take place if you left a heat gun pointed at the louvers long enough to heat them up. One more reason to keep that heat gun moving.
More discussion on Acoustats and heat guns here:
http://www.diyaudio.com/forums/planars-exotics/183168-acoustat-answer-man-here-91.html#post3851274
YES! The ultrasonic bias power supply is compatible with any Acoustat speaker. One of the several reasons that Acoustat changed to the ultrasonic power supply is that it is powered by a wall transformer of approx. 15 volts AC output. Therefore, one need only to obtain a wall transformer of the appropriate local mains voltage, be it 100, 120, 220 or 240 volts AC.
Another advantage of the ultrasonic power supply is that it is both adjustable and regulated. This means that you can set the voltage so that both speakers are exactly the same, and then it will remain fixed at that level regardless of minor variations in mains voltage.
AAM, can't you also could just put 220v on the 120v input to bias transformer and remove two diode / cap pairings and arrive right around 5kv? It would not be regulated or adjustable, but if one did not have the other Ultrasonic interfaces, this mod on a MK121 could work in a pinch?
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bias supply
Hi thanks for your help. The reason I asked about using the ultrasonic supply to change from 110v to uk220 is that I am going to use parts from a pair of spectra 11 that I have as the basis for a pair of 2+2s i also have acquired set of 121 2a blue medallion interfaces from the usa it is to convert these with spectra 11parts which are already220v .iam ready to start the frames but only have 6panels at the moment .hopefully I will be able to get the two i need soon preferably spectra but any wide panels will do .if you have any and can post to the UK let me know my email address is hroy25@gmail.com. cheers
Hi thanks for your help. The reason I asked about using the ultrasonic supply to change from 110v to uk220 is that I am going to use parts from a pair of spectra 11 that I have as the basis for a pair of 2+2s i also have acquired set of 121 2a blue medallion interfaces from the usa it is to convert these with spectra 11parts which are already220v .iam ready to start the frames but only have 6panels at the moment .hopefully I will be able to get the two i need soon preferably spectra but any wide panels will do .if you have any and can post to the UK let me know my email address is hroy25@gmail.com. cheers
That's truly unfortunate news. Also rather unusual in that many people have re-shrunk their Mylar without destruction. I don't think that this suggests that the other panels are 'on their last legs'. I recommend trying to replace the panel, as your speakers still have considerable value. If possible, seek out a panel with a bias lead that is yellow with a red spiral stripe. This indicates the latest type of conductive coating. A Spectra panel can also be used.