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Acoustat MK-121-B



 
 
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  #11  
Old August 22nd 08, 11:24 PM posted to rec.audio.high-end
Sonnova
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Posts: 1,337
Default Acoustat MK-121-B

On Thu, 21 Aug 2008 15:30:49 -0700, wrote
(in article >):

> Harry Lavo wrote:
>
>> One of the reasons to support Thiel....they make great speakers and they
>> still care about their 25 year old speakers.

>
> There are those with classic horn speakers from the 50s and 60s who
> appreciate the dynamic range and low distortion. Perhaps those are worth
> taking care of if, you like the sound. Yet, I wonder if any 25 year old
> box speaker can match what is made today? Obviously, the cost of repair
> might be significantly less than purchasing anything new. Budget is always
> a consideration, and it is much easier to re-foam a woofer, or replace a
> tweeter, than an electrostatic panel, even if you can find a replacement.
>
> I'm guessing that a company like McIntosh will support older products.


They sure used to. At one time, official McIntosh dealers would hold
amplifier "clinics" in which factory technicians with a truckload of
equipment would set-up in a dealer's premisses and would check-out, adjust
and repair - without cost (!) any McIntosh amp or preamp brought in by its
owner, regardless of age, and do so RIGHT THERE. If the amp needed new output
tubes, it got new output tubes. If it needed new capacitors, it got new
capacitors. That's what I call customer service. Of course, they stopped
doing that sometime in the 1970's.

> Pride of ownership cannot be discounted for that type of gear--an old
> McIntosh amp or tuner is something you might actually want to own. A 30
> year old Mac speaker is altogether different. If I owned one I would
> probably keep it. First, who today would want it? Secondly, if you found
> someone that did, they would proably not give you much for it--considering
> what they cost new. If I were looking to buy, I'd never consider such a
> thing.
>
> I recently had a chance to live with a set of Acoustat model 3s for a few
> weeks (before a friend sold them). I let him "store" them in my living
> room, as I wanted to relive the experience, and he didn't mind. The sound
> was as I remembered...OK in the context of an 80s speaker, but given their
> limitations (size, problematic room requirements, limited listening
> position, and overall weird look) I didn't much see the point.


You have a point. I had a pair of Acoustat Spectra 11s once and sold them
because their transformer wasn't very well designed and they would get
congested sounding as they got loud almost like a very poorly designed
broadcast limiter. The music would build to a crescendo, but at some point
would stop getting louder (even though it was supposed to) and each increase
in orchestra output would result in nothing but more and more distortion
until ultimately, they became unlistenable unless one turned the volume down
to point where the amp was no longer overloading the transformer. Not very
useful by today's standards.

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  #12  
Old August 22nd 08, 11:27 PM posted to rec.audio.high-end
Sonnova
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Posts: 1,337
Default Acoustat MK-121-B

On Fri, 22 Aug 2008 06:26:06 -0700, wrote
(in article >):

> Just to throw this out for a 25 + year old speaker. I have Acoust
> model X with the servo amps. I have had (myself) the amps refurbished
> with all modern parts. The frames and panels are original with the
> exception of modern dampening and other tech. I go to homes with $30K
> plus newer systems. I do not come home wanting more. My sound stage
> is as good if not better, bass, and high frequencies are right there.
> Any one reading these threads who has Acoustats, do not let them
> divert your attention. They are worth the effort.
>


I don't doubt that many of them are very much worth saving. There is, after
all, something magic about electrostatic speakers. Most are push-pull design
and therefore are capable of much lower distortion than are cone speakers and
most planar dynamic designs (which are single-ended, being driven only from
magnets on the front side of the diaphragm). Also, electrostatics (especially
full range) tend to be very coherent from top to bottom since all frequencies
radiate from the same surface and they tend to be naturally time-aligned (in
the E.M. Long sense) for the same reason. If the power supplies are adequate
and the transformer is properly designed, they can be very satisfying. OTOH,
Electrostatics tend to be light in the bass, they tend to beam and many have
a very small listening "sweet spot" **. Older designs have very little
response at either the top or the bottom (the original Quads) and tend to
suffer from arcing (extremely high voltage is required for them to work)
caused by a curious electrostatic field effect known as charge migration
where all of the static charge tends to concentrate at the point where the
diaphragm comes closest to the stator plates (the perforated panels covering
the diaphragm on both sides of the speaker). This point is, of course, the
place where the diaphragm moves the most and that's its physical center. If
not compensated for, this phenomenon causes only the center of the speaker to
produce any appreciable sound, and of course, excess excursion here will
cause the aforementioned arcing which can actually punch holes in the
diaphragm.

Modern designs have gotten around these various shortcomings and good modern
electrostatics are very good indeed, but the further one goes back in time
with earlier designs, one is going run up on these limitations. For instance,
back in the 1970's a company called Beveridge made some very expensive
electrostatic speakers with dedicated tube amps. The plates of the push-pull
tube amps connected directly to the stator plates of the speakers, thus
eliminating the double impedance conversion needed with most tube amp powered
electrostatics. While the Beveridges sounded quite good for their day, IIRC,
they could hardly play above a whisper without arcing. Arnie Nudel's Infinity
Servo-Static electrostatics were quite spectacular - on those rare days when
all of the small panels that made up the speaker's incredible surface area
worked at once - something that many critics maintained was a statistical
impossibility. And then there were the original Quads, where it all started.
These quirky speakers had marvelous midrange but absolutely no bass below
about 70 Hz and no treble above about 6 KHz. I've seen hybrid designs in the
'70's where a large frame held two Quads per side (one inverted over the
other to form a continuous arc from top to bottom) with a Decca ribbon
tweeter mounted between them and a large woofer in a box at the bottom of the
frame (forget who made these things but they actually sounded really good for
the time. They were terribly expensive though, as I recall). Of course, who
can forget the Dayton-Wrights of the late sixties and '70's which got around
the arcing problems by encasing the electrostatic elements in a bag full of
some kind of inert gas (hexaflourine?) to allow for more excursion without
danger of arcing. Finally, the first few generations of Acoustat speakers had
many of the above problems and should be avoided for the reasons mentioned.

**I once reviewed a pair of Roger Sanders' InnerSound electrostatics that I
thought sounded very good. The problem with them was that they had me
seriously contemplating checking antique stores for one of those "head vise"
contraptions that you often see holding people's heads still in old 19th
century deguerreotypes! As a listener, you literally couldn't move your head
an inch without losing all the highs. Setting the speakers up required that
one use a flashlight atop ones head pointing forward so that the beam hit the
wall exactly halfway between the two speakers. Then, you had to toe the two
speakers in until you could see the reflection of the flashlight beam equally
in both metalized mylar diaphragms! As far as I was concerned, this was
unacceptable, irrespective of how good the speakers sounded when optimally
set-up, and they WERE very good indeed. Who wants speakers that couldn't be
shared with others? This is a problem with lots of electrostatics, although
probably not to the extent of the InnerSound experience. Martin Logan gets
around this by curving his panels and they have a much wider listening angle.
In fact the "sweet spot" in most MLs extends to more than 30 degrees
off-axis.
  #14  
Old August 23rd 08, 04:47 PM posted to rec.audio.high-end
[email protected]
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Posts: 102
Default Acoustat MK-121-B

Sonnova wrote:

> They sure used to. At one time, official McIntosh dealers would hold
> amplifier "clinics" in which factory technicians with a truckload of
> equipment would set-up in a dealer's premisses and would check-out, adjust
> and repair - without cost (!) any McIntosh amp or preamp brought in by
> its owner, regardless of age, and do so RIGHT THERE. If the amp needed new
> output tubes, it got new output tubes. If it needed new capacitors, it got
> new capacitors. That's what I call customer service. Of course, they
> stopped doing that sometime in the 1970's.


McIntosh also encouraged their dealers to purchase expensive stereo
microscopes enabling them to inspect phono styli. With a dealer in my
area, this was a free service--to anyone. Although I never owned Mac gear
(I was a kid at the time) the dealer never balked at helping me out.

I am glad McIntosh has survived (although back then the equipment was simply
good value and built well, it is now priced distinctly in the
statosphere--maybe the result of not moving manufaturing facilities to
China). Sadly, in the late 70s and early 80s the high-end press always
talked the company down. In those days, you "needed" Levinson, or Audio
Research gear. It was just the way it was.

> You have a point. I had a pair of Acoustat Spectra 11s once and sold them
> because their transformer wasn't very well designed and they would get
> congested sounding as they got loud almost like a very poorly designed
> broadcast limiter. The music would build to a crescendo, but at some point
> would stop getting louder (even though it was supposed to) and each
> increase in orchestra output would result in nothing but more and more
> distortion until ultimately, they became unlistenable unless one turned
> the volume down to point where the amp was no longer overloading the
> transformer. Not very useful by today's standards.


Yes. Ironically, you also needed a beefy amp to drive the speakers. I
destroyed a decent, but typically adequate amp trying to drive Acoustats.
I was eventually forced to purchase the large Acoustat amp; yet, in spite
of the quality and power of this large mos-fet amp, the speaker always
sounded best at low levels.

Back in the 80s there were a lot of bad sounding speakers. The Acoustats
were not "bad" sounding. They just had a lot of limitations, and were
never SOA.

Michael

  #15  
Old August 23rd 08, 07:32 PM posted to rec.audio.high-end
[email protected]
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Posts: 102
Default Acoustat MK-121-B

Sonnova wrote:

> And then there were
> the original Quads, where it all started. These quirky speakers had
> marvelous midrange but absolutely no bass below about 70 Hz and no treble
> above about 6 KHz. I've seen hybrid designs in the '70's where a large
> frame held two Quads per side (one inverted over the other to form a
> continuous arc from top to bottom) with a Decca ribbon tweeter mounted
> between them and a large woofer in a box at the bottom of the frame
> (forget who made these things but they actually sounded really good for
> the time. They were terribly expensive though, as I recall).


The most famous iteration was Mark ("I never met a preamp that cost too
much") Levinson's HQD system, using the 24 inch Hartley woofer, all driven
by half a dozen (cheaper by the six pack--not!) ML-2, 25 watt class A amps.

Peter Aczel came up with a similar home-made device using the Janus woofer
and (I'm doing this from memory, so don't hold me to it) Dick Sequerra's
Pyramid tweeter. I think SME used a stacked Quad setup in their listening
room, too.

Michael
  #16  
Old August 23rd 08, 07:33 PM posted to rec.audio.high-end
Sonnova
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Posts: 1,337
Default Acoustat MK-121-B

On Sat, 23 Aug 2008 08:47:04 -0700, wrote
(in article >):

> Sonnova wrote:
>
>> They sure used to. At one time, official McIntosh dealers would hold
>> amplifier "clinics" in which factory technicians with a truckload of
>> equipment would set-up in a dealer's premisses and would check-out, adjust
>> and repair - without cost (!) any McIntosh amp or preamp brought in by
>> its owner, regardless of age, and do so RIGHT THERE. If the amp needed new
>> output tubes, it got new output tubes. If it needed new capacitors, it got
>> new capacitors. That's what I call customer service. Of course, they
>> stopped doing that sometime in the 1970's.

>
> McIntosh also encouraged their dealers to purchase expensive stereo
> microscopes enabling them to inspect phono styli. With a dealer in my
> area, this was a free service--to anyone. Although I never owned Mac gear
> (I was a kid at the time) the dealer never balked at helping me out.


I too was a kid but my dad owned McIntosh amps and a tuner/pre-amp.
>
> I am glad McIntosh has survived (although back then the equipment was simply
> good value and built well, it is now priced distinctly in the
> statosphere--maybe the result of not moving manufaturing facilities to
> China). Sadly, in the late 70s and early 80s the high-end press always
> talked the company down. In those days, you "needed" Levinson, or Audio
> Research gear. It was just the way it was.


A McIntosh M75 monoblock was 75 Watts (in the early '60's) and cost over $250
(this is when a Dynaco MkIII sold for about $80). That's at least $2-$3000 in
today's money, meaning that two of them would cost $400 or the equivalent of
$4-$6,000 2008 worthless Bush Bucks. I'd say that since today's Mac MC275 amp
is $4500 Bush Bucks, that McIntosh equipment is still pretty much the same
value it was then and has just kept-up with inflation.

McIntosh sort of lost their way in the 1970s with the introduction of
solid-state gear. Their expertise was in their exquisite bifilar wound output
transformers. Of course, transistor amps don't need output transformers, but
McIntosh's early SS designs incorporated them anyway (interstage transformers
too, IIRC). The result was that Mac 1st (and possibly second) generation
Solid-State amps didn't sound even as good as other companies' early
transistor efforts, and THEY were often lousy (early Dynaco ST-120s, and
Harmon-Kardon Citation 12s for instance). Add to that a cheaper, "budget"
line called simply 'Mac' and made in Japan, and you have a perfect recipe for
a more than slightly tarnished reputation. The high-end press in those days
was having none of it, of course and saw McIntosh's fall as illustrative of
the plight of the entire audio community as company after company abandoned
decent performing tube designs for lousy sounding, unreliable solid-state.

>> You have a point. I had a pair of Acoustat Spectra 11s once and sold them
>> because their transformer wasn't very well designed and they would get
>> congested sounding as they got loud almost like a very poorly designed
>> broadcast limiter. The music would build to a crescendo, but at some point
>> would stop getting louder (even though it was supposed to) and each
>> increase in orchestra output would result in nothing but more and more
>> distortion until ultimately, they became unlistenable unless one turned
>> the volume down to point where the amp was no longer overloading the
>> transformer. Not very useful by today's standards.

>
> Yes. Ironically, you also needed a beefy amp to drive the speakers. I
> destroyed a decent, but typically adequate amp trying to drive Acoustats.
> I was eventually forced to purchase the large Acoustat amp; yet, in spite
> of the quality and power of this large mos-fet amp, the speaker always
> sounded best at low levels.
>
> Back in the 80s there were a lot of bad sounding speakers. The Acoustats
> were not "bad" sounding. They just had a lot of limitations, and were
> never SOA.


No, not at all. I always thought my Spectra 11s sounded great a low volumes.
They were far from bad sounding. They just couldn't play at anything
approaching "realistic" volume levels, even in a relatively small room.
  #17  
Old August 24th 08, 12:20 AM posted to rec.audio.high-end
[email protected]
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Posts: 102
Default Acoustat MK-121-B

Sonnova wrote:

> The high-end press in those
> days was having none of it


The high-end press in those days was self absorbed and not very rigorous in
their ways (with one exception). From them, I would not place much value
in what was going down.

> No, not at all. I always thought my Spectra 11s sounded great a low
> volumes. They were far from bad sounding. They just couldn't play at
> anything approaching "realistic" volume levels, even in a relatively small
> room.


Read closely what I wrote. I never said they were bad sounding. They just
had limitations, and were never SOA. For a reasonably priced speaker they
were OK.

Michael

  #18  
Old August 24th 08, 03:04 AM posted to rec.audio.high-end
Sonnova
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Posts: 1,337
Default Acoustat MK-121-B

On Sat, 23 Aug 2008 11:32:52 -0700, wrote
(in article >):

> Sonnova wrote:
>
>> And then there were
>> the original Quads, where it all started. These quirky speakers had
>> marvelous midrange but absolutely no bass below about 70 Hz and no treble
>> above about 6 KHz. I've seen hybrid designs in the '70's where a large
>> frame held two Quads per side (one inverted over the other to form a
>> continuous arc from top to bottom) with a Decca ribbon tweeter mounted
>> between them and a large woofer in a box at the bottom of the frame
>> (forget who made these things but they actually sounded really good for
>> the time. They were terribly expensive though, as I recall).

>
> The most famous iteration was Mark ("I never met a preamp that cost too
> much") Levinson's HQD system, using the 24 inch Hartley woofer, all driven
> by half a dozen (cheaper by the six pack--not!) ML-2, 25 watt class A amps.
>
> Peter Aczel came up with a similar home-made device using the Janus woofer
> and (I'm doing this from memory, so don't hold me to it) Dick Sequerra's
> Pyramid tweeter. I think SME used a stacked Quad setup in their listening
> room, too.
>
> Michael


I believe that the ones to which I was referring were the Levinson HQD system
because the dealer at which I heard these things was an authorized Levinson
dealer.
  #19  
Old June 5th 18, 11:36 AM posted to rec.audio.high-end
[email protected]
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Posts: 1
Default Acoustat MK-121-B

Il giorno venerd=C3=AC 15 agosto 2008 05:09:32 UTC+2, ha =
scritto:
> Hello, I have acquired a pair of Acoustat tower speakers, they are the
> MK-121-B model. I was hoping that someone on this list could let me
> know if these are a rare find or just old junk!
>=20
> Also, any advice for setting them up, or what they would be worth to
> the right buyer.
>=20
> Thanks in advance!
>=20
> Chad


Hi! I have Monitor 4 and search two MK121, Where I can purchase?
Thanks
  #20  
Old June 5th 18, 06:24 PM posted to rec.audio.high-end
Peter Wieck[_2_]
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Posts: 20
Default Acoustat MK-121-B

Chad:

The last post was just under ten (10) years ago.
 




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