Manufacturers of high-voltage resistors seem to come and go, and during the life of the Spectra series, several different brands were used for the sector resistors. In fact, way too much of my time was spent qualifying new resistor vendors! The resistors varied in appearance, but were all pretty much the same specification. Vishay-Dale makes the HVX-2 series, which is rated at 5 watts, 15-kV working voltage, and has a flame-proof coating. The voltage rating is higher than necessary, but that comes with the 5-watt rating.
There are probably a handful of manufacturers making nearly identical parts. More than likely a special-order will be required, as resistors of this type are rarely stocked, but you might get lucky. Also take a look at distributors Allied Electronics and Newark Electronics.
Woofer replacement
I have owned a pair of Spectra 11's since 1990. They are still in exquisite condition. I have never tweeked or messed with them. I also run them with an M&K subwoofer. Is there a mod or replacement to the Spectras original woofer that I can do to get a deeper and tighter bass? Just wanting to enjoy them without the addition of the sub. You know, never can leave well enough alone.
I have owned a pair of Spectra 11's since 1990. They are still in exquisite condition. I have never tweeked or messed with them. I also run them with an M&K subwoofer. Is there a mod or replacement to the Spectras original woofer that I can do to get a deeper and tighter bass? Just wanting to enjoy them without the addition of the sub. You know, never can leave well enough alone.
Hello - I have a pair of Model 3's 1984 (all black). I have loved these for all these years. I sold them and got these on SA from the store I worked at. DS Audio in Reading PA. They are now next to the 60 inch and look great in the theater room. I always wanted a pair of Model 8's though.
I now have a ticking from one side. HV cap discharge I would imagine. Do you know anyone who rebuilds the HV board? I want to keep them but the wife is not into the tick tick tick.
I now have a ticking from one side. HV cap discharge I would imagine. Do you know anyone who rebuilds the HV board? I want to keep them but the wife is not into the tick tick tick.
unplug... play music until nil sound... remove interface cover... now you have a couple of choices.
The goal is to short the stator wires to the center wire/bias supply wire...
The power supply is already discharged at this point for all intents and purposes, but we can make sure later.
you can use an insulated handle needle nose pliers to undo the nuts holding the stator wires, and/or take the center pin that holds the HV bias wires, now you want to touch that wire to the stator wires (there are two), or alternately take each stator wire and touch it to the center wire, and/or to each other...
Keep ur OTHER HAND off the box, and you body off the box when you do this. Do NOT do this if you have a heart condition or use a pacemaker (fwiw)
it will make a noise in the speaker, and maybe a spark. Do it until there is nothing... or keep them together.
You can then take a wire or the open jaws of the pliers and short the ctr pin to the stator terminals, each side...
all discharged now.
Worst case is like a damn strong static electric spark... will make a jump back a little, but not more than that. That's why you keep ur body and hands off the case - and off GROUND too!
_-_-bear
Btw, what the heck needs to be "refurbished"??
Ticking is likely a discharge in the cells, not the HV supply.
This can come from dirt, dust, excess humidity, too little humidity, AND importantly the wires at the ends (typically) of the cells coming loose from the glue bond and becoming too close to the cells.
Try this - you have to remove the socks from the top... take the top plate off, take out the 4 billion staples (why they used so many??), slide the sock down... speaker can be on for all this , if you like...
In a PITCH DARK ROOM, sit there and listen and look for the discharge!
Quiet room helps too... late night usually best...
You may have to move your vantage point to find it...
In the case of a loose stator wire, the cures have been posted before...
If it is dirt, the cells should first be vacuumed, preferably with a soft hair vacuum brush (not these hard synthetic modern ones) (make sure IT is clean by washing it and making sure it is dry). If that fails, then they can be washed, but you have to make sure that if you dip them, not to try to lift them in the horizontal position and get water load on the mylar...
those instructions too were discussed some time back...
One danger is that persistent arcs in the same spot across something like plastic will create a carbon track that is difficult to remove and defeat... but usually not impossible.
_-_-bear
Thanks Bear
That does sound more like it. The ticking is from one spot at the bottom of the center panel.
To anyone who had something to do with the making of Acoustats over the years I want to send out a big "LOVE YA" men and ladies.
My first exposure was as a customer of DS Audio in Reading. I would go in and listen to album after album on model 2 and 4's. The real old tube amped ones that leaned back.
Everyone else wanted to hear and Mag Tymp 4's with the sub panels on Audio Research electronics. But I was hooked. I had to walk out that day with powered Advents due to budget. Still was a great day.
Next thing I knew I was working at the place. I heard many more and of the newer 1980's + models and they kept getting better and better. We had some great listening rooms at DSA. In a room with Mag MG3's and Acoustat Model 3's I broke down and bought a pair. My sales partner bought the MG3's. They were nice but even that ribbon didn't have the spark of detail on axis of the 3's. The sub models started coming out but I didn't like them as much. And I do very large scale sound reinforcement systems and I love base from cones. I didn't like the cone with them. They didn't need it for one and the low mids were not the same.
And the Acoustat TNT200 was one of the best amps I have ever heard on almost any speaker. WOW what a amp. My budget would keep me from getting one then Hafler/Rockford/China and gone. I used this amp against everything we had. Krell, Threshold monos, Tandburg mono's, Sony Esprit, A.R., Electrocompaniet, C.J., and many many more. No contest. Sorry to all those "golden hears" but I lived at this place and heard these day in and day out, even at home on my 3's. I am missing those days.
That does sound more like it. The ticking is from one spot at the bottom of the center panel.
To anyone who had something to do with the making of Acoustats over the years I want to send out a big "LOVE YA" men and ladies.
My first exposure was as a customer of DS Audio in Reading. I would go in and listen to album after album on model 2 and 4's. The real old tube amped ones that leaned back.
Everyone else wanted to hear and Mag Tymp 4's with the sub panels on Audio Research electronics. But I was hooked. I had to walk out that day with powered Advents due to budget. Still was a great day.
Next thing I knew I was working at the place. I heard many more and of the newer 1980's + models and they kept getting better and better. We had some great listening rooms at DSA. In a room with Mag MG3's and Acoustat Model 3's I broke down and bought a pair. My sales partner bought the MG3's. They were nice but even that ribbon didn't have the spark of detail on axis of the 3's. The sub models started coming out but I didn't like them as much. And I do very large scale sound reinforcement systems and I love base from cones. I didn't like the cone with them. They didn't need it for one and the low mids were not the same.
And the Acoustat TNT200 was one of the best amps I have ever heard on almost any speaker. WOW what a amp. My budget would keep me from getting one then Hafler/Rockford/China and gone. I used this amp against everything we had. Krell, Threshold monos, Tandburg mono's, Sony Esprit, A.R., Electrocompaniet, C.J., and many many more. No contest. Sorry to all those "golden hears" but I lived at this place and heard these day in and day out, even at home on my 3's. I am missing those days.
Hi guy's i know someone that paid 5k for a pair of 6600s and very happy he did of course i'm not biased one bit.
Hi Moray i come on this site because i'm an Acoustat fanboy ( 66 years young ) i know NOTHING about DIY i leave this for my friend Jocelyn in 28 years i have owned Spectra 22s - 33s - 2+2s - and three pairs of 1+1s loved them all BUT the 1+1s are my favorites BUT you are so right if you like your music loud then the 2+2s are a better choice BUT again if you have the room i have a couple of friends with 6s - 66s - and highly modified 6600s for the money NOTHING come's close i want to thank you for helping Acoustat lovers preserve their speakers. André
An externally hosted image should be here but it was not working when we last tested it.
Andre, how did your friend, Jocelyn, modify the interface?
Seeing the wall wart power supply inside the box makes me think that he combined a Spectra interface with the regular MK121C interface.
Why?
What I see inside the interface enclosure is the audio electronics for a standard MK-121 interface, mated with the ultrasonic power supply from the Spectra series. This does not make it a 1+1 Spectra. That would require segmented panel-drive, which the MK-121 does not support.
By the way, a very nice job of custom packaging!
Acoustat never used aluminized mylar. All products, from the beginning to the end, used a heat-shrinkable Mylar diaphragm with a custom-formulated, carbon black-based coating that was applied by brushing it on. In the late 80's Acoustat did introduce an improved, higher-resistivity version of that coating, but to the naked eye it looked the same - flat black.
Aluminized Mylar is generally considered too conductive to be of any use in an ESL design (which is not to say that some brands may have used an aluminum-bearing compound in their coating). Constant-Charge operation requires a high-resistance coating.
While Solen may be a step up from the original caps Acoustat used I replaced the Solens with MIT PPFXS and RTX bypasses in both my Acoustats, Martin Logan Requests, and CLX - each time with noticeable improvement in detail, resolution, and dynamics. Yes very expensive and big, but really worth it if you want to hear what your electrostatics can do. The Dueland resistors he used are the best, their capacitors are very good too, but cost more than a car to do 4 caps in each of the CLX's
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