Arc Damage

[Gliding Dutchman]

Hi there,

I did a search for the term "arc damage" and found no tread post regarding the matter.

...so this made me wonder... are ML panels immune to arcing?

If you owned QUAD ESL speakers you'll now the term "arc" all to well... he-he!

GD

 

[roberto]

Hi there,

I did a search for the term "arc damage" and found no tread post regarding the matter.

...so this made me wonder... are ML panels immune to arcing?

If you owned QUAD ESL speakers you'll now the term "arc" all to well... he-he!

GD

No problem with arc MLs. I have being with the company since 87, and never had an arc problem, even that we played them very loud. Happy listening,
Roberto.

 

[Bernard]

If you owned QUAD ESL speakers you'll now the term "arc" all to well... he-he!

GD

I had Quad 57s for 22 years and they never arc'd. I drove them first with a Quad 303 (45W/ch), then a Bedini 20/20 (20W/ch), a Dyna Stereo 70, and then a Copland 50W/ch tube amp. No sparks at all.

 

[amey01]

I think ML have done some very extensive research on the issue and basically combat it. I wouldn't say they're "immune", but I'd be very surprised to hear any report of it in ML.

 

[C.A.P]

I have had a few shocks from them while playing around with the panels. Its not a big one but it lets you know they mean business.

 

[Gliding Dutchman]

Me too CAP...! I pushed too hard from both sides of my one faulty panel and the speaker firmly "told" me to let go... shocking!! He-he!

D

 

[leif_erikg]

Arc's???

Never seen an arc on my Request or Clarity's

 

[JonFo]

I've messed around a lot with my set, and have never seen evidence of an arc in the panels.

I push them really hard (all panels individually driven by 800@4Ohm, 1600@2 Ohm w/ch), and have never heard diaphragm slap or seen arcing.

The only time I've heard anything is when a small moth got into one of the panels and went 'zzzit', I then had to vacuum the remains off, but no panel damage at all.

 

[C.A.P]

Me too CAP...! I pushed too hard from both sides of my one faulty panel and the speaker firmly "told" me to let go... shocking!! He-he!

D

Exactly ! been there done that !

I've messed around a lot with my set, and have never seen evidence of an arc in the panels.

I push them really hard (all panels individually driven by 800@4Ohm, 1600@2 Ohm w/ch), and have never heard diaphragm slap or seen arcing.

The only time I've heard anything is when a small moth got into one of the panels and went 'zzzit', I then had to vacuum the remains off, but no panel damage at all.

Oh the famed left over powder and shrapnel from the arrant moth that got to close. Yup been there done that too.

 

[Rich]

are ML panels immune to arcing?

From the ML website regarding panel manufacture:

We then coat the perforated metal with a Nylon insulator and fire it in a huge oven at over 575 degrees Fahrenheit to fuse the Nylon directly to the steel. This not only provides critical insulation but also eliminates the need for a grille cloth, which could degrade sound quality. Each stator is arc tested to 10,000 volts (twice the panel's working voltage).

. . .

We plasma-deposit the ultra-light, 0.0005-inch-thick polyethylene terathylate (PET) diaphragm with a conductive coating in a $20-million, oxygen-free argon environment chamber. This ensures extreme consistency across the diaphragm surface and enables it to accept high voltages without danger of arcing.

Basically, they have proprietary coatings for the metal grills and the mylar diaphragms that inhibit arcing. It isn't necessarily completely non-existent, but the lack of any previous threads on it in a forum as comprehensive as this should give you an idea that it is pretty much a non-issue.

 

[rhd1953]

My CLS IIa's will arc with enough watts!

If the room is dark you will see a tiny spark and hear a sharp snap! If it occurs offen enough a 'grey' spot will appear on the black stator (at that spot).

In summary, once weak (poor or damaged insulation) spots occur, following arcs/sparks will occur at that point(s). My amps are 180 watts @ 4 ohms. I've owned my CLS II's since 1989 and replaced the panels once.

I doubt that a 25 watt amp would ever produce an arc/spark.

 

[Gliding Dutchman]

I doubt that a 25 watt amp would ever produce an arc/spark.

Ey?? My amp produces around 200 watts per channel into 4 ohm rising to 550 peak at 1 ohm...

Well, it seems actually a bit weak for the CLS II panels.

D

 

[rhd1953]

To clarify...

Perhaps I wasn't clear. My CLS II will arc at very low frequencies (bass) if driven hard. They have never "arced" at mid or high frequency inputs. When my CLS II's arc I hear a sharp snap.

My old panels had "grey" areas at these arc points (on the black stators). The protective coating no longer provided complete insulation.

You were asking about arcing and damage, right?

 

[Gliding Dutchman]

Yes, yes... but does this arcing damage the diaphragm?

 

[rhd1953]

I'll check...

I still have my old panels, I'll check them. I would say yes though, neither surface is designed to be exposed to arcs. That's the point of the insulating coating on the stators. If you could recoat that spot (on the stator), then perhaps the diaphragm couldn't arc there.

 

[Gliding Dutchman]

Wish I could buy your old panels as I am having an uphill time refurbing mine...

 

[rhd1953]

Not usuable

You really really wouldn't want my old ones. See photos.
I live about 400 miles from Martin Logan (Kansas), the best replacements are there!

 

[Gliding Dutchman]

I am again thousands of miles from you...

La-tee-da... just have to refurb my panels myself. The only option.

You see, new panels are also a problem. The owner of the company that was the agent for ML in South Africa died in December last year and the company collapsed - I actually bought these CLS II's from the previous owner because he ordered new panels from the SA agent and then the sad news happened.

GD

 

[Adri]

I am again thousands of miles from you...

La-tee-da... just have to refurb my panels myself. The only option.

You see, new panels are also a problem. The owner of the company that was the agent for ML in South Africa died in December last year and the company collapsed - I actually bought these CLS II's from the previous owner because he ordered new panels from the SA agent and then the sad news happened.

GD

If there's no official agent, importer or distributor for ML in South Africa, you can order them directly from ML USA in Kansas.
Probably works out even cheaper then using an agent, if I look at the inflated prices for replacements parts and panels in Europe.

Adri.