Speaker wire connections/terminals for use with ML's

[Bernard]

I would agree in jewelry use, but my idea is to tip my cables with it to fill any voids in and around the few strands of my Audioquest cables. It is more to coat against oxidation and to make a better contact with my termination spades. Once assembled and positioned it should hold nicely...............

So I assume that you are going to only crimp the connection without using any solder, as the solder would fill in the spaces....you could use silver solder.

On a somewhat related matter, many years ago I read an interview with the manufacturer of my tonearm (a Syrinx at the time) that in the newer models they were soldering the wire to the cartridge clips instead of just crimping them as it sounded better. As I had the older version arm I got out my soldering iron and fed some solder into the crimped connection. I was amazed at the improvement in sound. Of course, this was at a much lower signal level that the speaker spades.

 

[nsgarch]

Counter-intuition

Something is escaping me here: I always thought that stats behaved like giant capacitors

Well, they're constructed like a giant (unrolled) capacitor, in that there are three "foils" separated by air dielectric. However, unlike a capacitor, it is not charging and discharging, it just stays charged, with the polarity of the two stators changing as an analog of the signal. But they are not passing an alternating current from one side to the other, like a capacitor in a circuit. Think of the three elements (two fixed, one flexible) like three electrical cul-de-sacs, just sitting there with a high potential (voltage) applied to each one -- a static (non-moving) charge.

What causes the flexible diaphragm to move forward or backward is electrostatic force -- a very very weak force, across the air space, created simply by the slight attraction or replusion of the diaphram to the front/back plates. I emphasize weak, because unlike the forces created in an electomagnetic driver, static force, as you know, is barely enough to make your hair stand on end There is no reactive force (like from a cone driver) because the mere movement of the diaphragm between the stators can never create even a tiny electric current. Whereas a voice coil moving back and forth in a magnetic field is in itself an electrical generator, sending an opposite signal back toward the amp.

Also, if there is not much current flow, it stands to reason that you do not need a high power amp to drive them,

Guess what? You don't! And yes, I've read about (but not heard) Soundlabs being driven with OTL tube amps (not SET's.) Which brings me to my favorite part: Amps for Stats (hybrid woofers separately powered of course ;-)

First, may I take a minute to remind everyone that the grandaddy of elecrostats, the Quad 57 was originally powered by a little 15W/ch tube amp, no problem. Yet the 57 has a nominal 16ohm impedance, but swings from 1.8 ohms to 60 ohms!

But, it is well-known that you do need higher-powered amps to drive MLs

Only if you are using a SS amp and/or driving a hybrid model. The CLS, Vantage, and Summit require only a modest tube amp.

OK. Watts (power) = Amps (current) x Volts (potential force) In a stat, there's no flow of electrons to speak of (where can they go?) They just pile up and sit there in those cul de sacs as a charged potential (voltage.) SS amps blow up if you short the speaker terminals, and 1 ohm is getting precious close to a short! As the load impedance goes down, and the SS amp's output (in Watts) starts to rise, all the stat wants from those Watts is high voltage, but a SS amp's power (watts) is primarily made up of high current (x) lower voltage. However, if you use a really high powered SS amp, one that's practically idling, even during loud passages, it's in no danger of clipping/oscillating or producing distortion even when the load occasionally drops to one ohm. But that explains why you need a big SS if you want your stat to sound good with SS. If it's a low powered SS amp, just don't play it too loud and it will be OK. (This doesn't apply to SS amps with output transformers, like McIntosh.)

Tube amps will suffer if you run them with nothing connected to the speaker terminals (just the opposite of SS amps.) Their power output (Watts) doesn't vary much with load impedance. So as you crank up the volume, or reduce the load (impedance of the speaker,) the current AND the voltage both increase together. So with a tube amp, a stat gets plenty of voltage at fairly modest power output (watts.)

Most of you know that except for a few resistors and capacitors (crossover network,) when you connect an amp to a conventional speaker, its power goes through the voice coil. Does everyone know what the amp 'sees' when it's connected to stat? (Not the panels ;-) It's connected to an input transformer that converts the amplifier's signal to a very high voltage, low current (amperage) potential that is then connected to the (front and back) stators. Believe me, at 5,000 volts or so, if there were any current in that panel, you couldn't even put you finger near your speaker without being electrocuted!

The output from a power tube is already a high voltage, high impedance signal -- just what the doctor ordered for an electrostat! So why bother with the amp's output transformer, or the stat's input transformer? Couldn't one just hook up the power output tube(s) directly to the stat's panels? Yes! (OK, there's a little more involved, but really not too much!)

So although I can't answer your question about SET amps, (they're typically very low power, and stats aren't efficient) OTL tube amps work very well with electrostats, and should definitely be a consideration.

If one has grown up with even a little understanding of how conventional speakers/amps work, then trying to apply that same understanding to electrostatic speakers becomes counter-intuitive, and will only give one a severe headache. Find somebody who really understands how an elecrostat works from an electronic point of view (we all get how they make the air move ) and have them explain it to you in detail.

 

[Bernard]

Well, they're constructed like a giant (unrolled) capacitor..........

Thanks for the explanation. I had forgotten one basic thing about stats: it's not the music signal that charges the capacitor; it is the HT supply in the speaker that does so. The music signal just modulates the diaphragm, producing sound.

 

[hcheu]

when used with stats, highly stranded cables tend to build up a lot of capacitance, since they're mostly providing a strong static potential, but not much in the way of current flow back and forth. So fewer, or solid conductors are said to be preferred for use with stats to avoid high frequency rolloff.

Hi "nsgarch"
I found the same from my own experience comparing Linn 400K and Cardas golen reference cables myself. The Linn, at a small fraction of the Golden Reference's price, works better. The only thing I could think of, as you have confirmed, is cable capacitance. But Linn is still not ideal. Do you have any recommendation?

 

[nsgarch]

I found the same from my own experience comparing Linn 400K and Cardas golen reference cables myself. The Linn, at a small fraction of the Golden Reference's price, works better. The only thing I could think of, as you have confirmed, is cable capacitance. But Linn is still not ideal. Do you have any recommendation?

I recommend that every MartinLogan stat owner (and especially if you also use a ss amp) read Roger Sanders' "white paper" on the special requirements of speaker cables used with electrostats: http://www.sanderssoundsystems.com/Cable White Paper.htm
Sanders of course makes a cable just for stats. Tara Labs and Purist both have new solid conductor designs, and of course the Speltz Anti-cable seems like a good candidate for relatively little money.

 

[tonepub]

The old Acoustat X speakers that used an OTL amplifier and no
transformer network was quite good....

There is still a guy out there that rebuilds these amplifiers and
you can even use them in place of the interface on the "modern"
Acoustats. (models 1-4, including 1+1 and 2+2) Very transparent sounding.

The Old Quad 57's did well with small, low powered tube amplifiers
because they had no dynamic range, a pretty limited frequency response
and would not play loud at all.

The reason most tube amps suffer with modern electrostatics (ML included) is the varying impedance curve. The Summits go down to .7 ohms at 20k.
That means current, and current means power. Most people complain that their Summits (or Vantages) sound "soft" with tubes and that is because a lot of tube amps just can't put out significant power at less than one ohm.

The older CLS and even the Aerius only went down to about 2 ohms at 20k. Much easier to drive than .7, which is almost a short.

I've heard the Summits with ARC ref amps as well as the big Manleys with excellent results, but not with small tube amps and certainly not an SET...
You need power for dynamic range....

 

[nsgarch]

The Old Quad 57's did well with small, low powered tube amplifiers because they had no dynamic range, a pretty limited frequency response and would not play loud at all.

You must have read this somewhere. It's the stock myth about Quad 57's and you're perpetuating it. My actual experience listening to my friend's original 57's driven by a 40W/ch Marantz 8b is they have stunning midrange, better bass than any other full-range pure stat, except Soundlab, excellent dynamics and high frequency response. Of course we have better sources, preamps, and cables now, so maybe those vintage myths need revision and these great sounding speakers given an updated assessment

The reason most tube amps suffer with modern electrostatics (ML included) is the varying impedance curve. The Summits go down to .7 ohms at 20k.

More misinformation. It's solid state amps, not tube amps, that "suffer" when the speaker impedance drops to a short circuit. Lots of ss amps went into high frequency oscillation and were blown up by ESL's in the old days, before ss amps got bigger, and protection circuits were added.

That means current, and current means power.

No, watts means power. Watts = current (amps) X potential (volts). And no, stats don't require big watts as long as they can get strong voltage to keep those panels charged. Stats have little use for current since there isn't any electron flow, unless the panels begin arcing, God forbid!

Most people complain that their Summits (or Vantages) sound "soft" with tubes and that is because a lot of tube amps just can't put out significant power at less than one ohm.

I don't know any "most people", however the half dozen tube-driven Summit/Vantage owners I talk with, would find "soft" a totally ludicrous characterization!

Output transformers dictate that tube amps put out more or less the same power (watts) at any load impedance, even 1 ohm. And since electrostatic panels don't consume current, the tube amp's watts (current x volts) are consumed mostly as volts, to charge the panel elements. By contrast, as the load impedance goes down, a (transformerless) SS amp must deliver more current to satisfy Ohm's Law (since its voltage stays constant.) That is why a 100W/ch tube amp and a 200W/ch ss amp are essentially equal in the eyes of an electrostat An electostatic driver works through the tiny attractive or repulsive forces produced by high voltage potentials stored in its elements. There is no voice coil or ribbon through which electrons flow (current) making a tube amp ideal for driving a purely electostatic device. And OTL (output transformer-less) tube amplifiers (not SET) have also had great success driving electrostats, since basically only one transformer is necessary between the tubes and the panel.

I've heard the Summits with ARC ref amps as well as the big Manleys with excellent results, but not with small tube amps. You need power for dynamic range....

No, that's another myth. You need power for high sound pressure levels in large spaces using electrodynamic drivers (voice coils.) Electrostatic drivers are champs when it comes to dynamics (= rendering the entire loud-to-soft range in proper proportion.) Big Wolcotts or ARC amps are only necessary if they have to drive woofers along with the stats. Otherwise, you can do just fine with a 150W +/- tube amp. Don't take my word for it, just read your Summit Owner's Manual

 

[Jungle Jack]

Hello,
Another connection option that I have used to good effect are the WBT jumbo spades. Though somewhat expensive, the quality of these German built terminations are truly outstanding. They also have really cool locking bananas that work quite well. These are available through Parts Connections I believe.
Cheers,
Mark