Acoustat Answer Man is here

That eBay listing for the souped-up Servo amps is a real hoot. The comments (especially the answers to questions) are full of mis-information and myth, especially regarding the 'X' style of interfaces (one presumes the writer is referring to the Spectra series). And BTW, neither David Hafler nor his company had anything to do with the servocharge amps - they were out of production LONG before he acquired Acoustat.

These modified amps may be an improvement over the original, but the outboard, exposed high voltage components are so dangerous that I would not wish their ownership upon my worst enemy. Buyer beware.
 
That eBay listing for the souped-up Servo amps is a real hoot. The comments (especially the answers to questions) are full of mis-information and myth, especially regarding the 'X' style of interfaces (one presumes the writer is referring to the Spectra series). And BTW, neither David Hafler nor his company had anything to do with the servocharge amps - they were out of production LONG before he acquired Acoustat.

These modified amps may be an improvement over the original, but the outboard, exposed high voltage components are so dangerous that I would not wish their ownership upon my worst enemy. Buyer beware.

Agree about Hafler not having anything to do with the servocharge amps.

Yes, dangerous. Dan taught me enough to use a high voltage probe to test the amps, set bias, etc. I ran my pairs with the cages off, too. In the end, without the protection circuitry they were open to all sorts of damage if the power would happen to go out and come back on before you could flip the switches on the amps.

Yeah, waaayyy better sounding than the original Servo amps. Still some of the very best amps I've ever heard. Especially with the full wave transformers we had made.
 
I would think a littel on bouth ....the monster wire..was ONe of the top dogs back in the 70-80s.......
an most wire used back then sucket....i was in the Audio bizz in the 80-90s ....I spoke to Mr pass about wire in his amps we were saleing....He thought the 18ga juke wire was fine an even 16ga was over kill...he told me then.... it made No diff in the sound of his amps.....need less to say he changed his tune ....he also though bal input had no place in the home Audio............now most of his amps are all bal....gofig....
Long live Acoustat...
 
My 2+2's have that little placard that says wiring by Monster Cable. Was this really done to improve sound or did Acoustat have a deal where they got super cheap or free wire from Monster in return for putting the Monster sticker on the interfaces?

I don't know the history behind Acoustat's use of Monster Cable in the interfaces. That practice was discontinued long before I joined the company. I'm sure, however, that Acoustat was able to obtain the wire rather cheaply in exchange for the advertising value of the placard on the outside of the interface.

In retrospect, using that wire was not the greatest idea, as the wire has a strong tendancy to oxidize (turn green) even beneath the plastic insulation. If I remember correctly, it was Acoustat's policy to remove that wire during the very popular Medallion Transformer upgrade program. That very oxidized copper was impossible to resolder.

So what to do if you have Monster Cable in your interface? There is probably no urgent need to replace it, unless the interface is being serviced for other reasons. In which case, I would recommend replacing the Monster Cable with your choice of cable.
 
Has anyone had any experience with the Sanders Magtech amplifiers? I have 1+1's, 2+2's, 3's and 4's (looking for a pair of 8's should anyone have a pair for sale). I am currently using the Music Reference RM200 and I think I am clipping when played loud. I have heard the Sanders amplifiers at the CES (The Show) and they sound quite good but they were driving his ESL's. Just curious what the thought was about this amplifier or any other solid state that won't break the bank, budget about $4000.00-5000.00. Thanks in advance..............Bob
 
Has anyone had any experience with the Sanders Magtech amplifiers? I have 1+1's, 2+2's, 3's and 4's (looking for a pair of 8's should anyone have a pair for sale). I am currently using the Music Reference RM200 and I think I am clipping when played loud. I have heard the Sanders amplifiers at the CES (The Show) and they sound quite good but they were driving his ESL's. Just curious what the thought was about this amplifier or any other solid state that won't break the bank, budget about $4000.00-5000.00. Thanks in advance..............Bob

Don't know about the Sanders amp, but with that array of Acoustats you have plenty of panels to use if you build your own Model 8 frames. :)
 
Don't know about the Sanders amp, but with that array of Acoustats you have plenty of panels to use if you build your own Model 8 frames. :)

Enough panels, yes, but that still won't make a true Model 8. The Models 6 and 8 used special interfaces with a different low frequency transformer that provided less bass boost than the regular MK-121 interface. Using a regular interface with that many panels will result in too much bass for most peoples' taste.
 
Enough panels, yes, but that still won't make a true Model 8. The Models 6 and 8 used special interfaces with a different low frequency transformer that provided less bass boost than the regular MK-121 interface. Using a regular interface with that many panels will result in too much bass for most peoples' taste.

Good point. Probably doable to obtain (custom made, perhaps) the different transformers to re-create the Model 8 with two pairs of interfaces. Not a simple thing to do, though.
 
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I got two new wallwarts off ebay for $7 each. Work perfect. Nothing to them. Just make sure you get the correct voltage - either 15VAC or 12VAC - I would just get the 15VAC and follow the bias setting as shown from Audio circuit.com...

As far as the model 8 interfaces, can't you just use the 4 panel setting and a digital equalizer to tame bass? That's what I plan on doing with my model 6 build. I use a Behringer DEQ2496 to equalize bass for optical pass through from source to DAC - EQ done in in digital domain - works fantastic.
 
I just purchased a set of Spectra 1100's and am in need of the ultrasonic wall transformer, the acoustat wall-wart, Does anyone have any ideas where to get one? Soundvalves no longer has an ebay account.

Go to eBay and search for Acoustat - the wall transformers appear frequently. If you don't find them, try again in a few days.

There is nothing magic about the Acoustat wall transformer. Any wall wart that puts out 15 volts AC, with at least a few hundred milliamps will do the trick.
 
...As far as the model 8 interfaces, can't you just use the 4 panel setting and a digital equalizer to tame bass? That's what I plan on doing with my model 6 build. I use a Behringer DEQ2496 to equalize bass for optical pass through from source to DAC - EQ done in in digital domain - works fantastic.

Yes, I'm sure that equalization could be used to compensate for the 'incorrect' transformer, provided that your equalizer has sufficient flexibility to get the frequency and slope correct. I suspect the resulting equalization would be more of a shelving function, as opposed to a steady X-dB/octave roll-off.
 
2Q==
This is the wall-wart that I purchased(pictured). It reads input: 120V 60Hz 9W Output:15VAC 150maH. When I first plugged it in I didnt have the ESL's connected and I touched the amp and it gave me a bad shock. Then I plugged them in, no shock, and there was no change in sound. I can here sound coming from the ESL's very faintly. The woofers work great, I turn them off to hear the faint sound coming from the ESL's. Should this adapter be working by itself? Is there some other transformer that's needed? Could there be something else wrong with the ESL's?
Thanks
 
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Check your input wall wart power jack on the back of the interface. Mine was very loose and loosing connectivity to the pcb board. Does the red LED light when plugged in or flash on / off as you jiggle the jack? As long as the red LED is on you should be charging the bias.

You got a shock? What were you touching? Was the panel connected to the interface?

You touched the amp (not the interface) and got shocked?? You may have your bias short to speaker connections somewhere...were you doing a mod or something inside the interface?
 
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2Q==
This is the wall-wart that I purchased(pictured). It reads input: 120V 60Hz 9W Output:15VAC 150maH. When I first plugged it in I didnt have the ESL's connected and I touched the amp and it gave me a bad shock. Then I plugged them in, no shock, and there was no change in sound. I can here sound coming from the ESL's very faintly. The woofers work great, I turn them off to hear the faint sound coming from the ESL's. Should this adapter be working by itself? Is there some other transformer that's needed? Could there be something else wrong with the ESL's?
Thanks

No other components are necessary. If you mean that you got a shock from the speaker's 'black box' interface (and not the power amplifier) that is actually a good sign, in that it means the circuit is producing the necesssary high voltage. If indeed you got a shock from the amplifier, then something is very wrong.

Note that there is no LED on the Spectra 1100 - the LED is present only on the full range Spectras. BEFORE connecting the wall transformer, be sure that the panel wires are connected properly to the interface (see the manual: they are color-coded). Also connect the white plug from the interface to the top of the woofer box, being careful that it is properly oriented (it's a keyed connector). THEN connect the wall transformer and the amplifier, and the speaker should begin to play almost immediately, although it will take a few moments for the panels to fully charge.

Yes, there could be something wrong with the speaker - did you audition them before purchase? The good news is that the chance of something being wrong with the ESL panels is very low. If there is a problem, it is most likely in the interface, and those problems can usually be easily remedied.

Do write again after you've had a chance to check your connections.
 
Thank you for your replies, I have the five wires from the esl's connected to the interface. (it was the interface i got the shock from before the esl's were connected) I have the white plug properly connected from the interface to the woofer box. I have the manual and double checked that I did all this right and I let them play for a while. The marginal amount of sound coming from the esl's is the same as if they were not powered.
I did not audition them before I bought them, I do not know if they work.