[gerG]

Contrary to the appearance, some thought went into this. Bottom line: to avoid cracking or reduce crack growth, I wanted to put the outer perimeter in compression (reduce tensile hoop stress in the jargon of the trade). This requires a simple band with quite a bit of tension around the outside. The quick solution is a zip-tie, until I devise something more elegant. The location and direction of the zip-tie is kind of important. I tried a few orientations and this worked best. Use a good small tie (color will always affect the sound

). The important thing is to get hold of a zip-tie gun to tension and cut the tie. It must be tight to do any good. Pics:

gerG

 

[gerG]

Just one more, because I think these cans are so pretty! What a gorgeous sexy design. I only hope that I can get them to sound as good as they look.

gerG

 

[Xecter]

A design flaw, Easily FIXED!


To be absolutely honest, I did not notice the Zipties on your second post, until i read what you did.


What causes the cracks? Twisting?

 

[doobooloo]

Nice practical mod, gerG!

But what do you mean, you hope to get them to sound as good as they look. They don't sound that good? I thought the A1000 was well loved by the owners here!

 

[gerG]

Xecter, I am not certain what is causing the stress, but it is a stress fracture. To be honest I had only read descriptions of the failure. Mine aren't cracked, and I hope to keep them that way. After I posted this I saw Construct's photo:

I have read theories about the limit pin being the culprit. I hope that is it, because those will be coming out of there anyway. I will get around to taking them apart one of these days and figuring it out.

btw, has anybody seen any official info from AT on this issue?

Hey doobooloo, good to hear from you! I do think that these are the best sounding AT cans that I have heard. Unfortunately they are still outclassed by any of my Beyers. The bass response needs serious help (DADS is a screw-up, imho), and there are a couple of holes in the midrange. Fortunately they respond reasonably well to equalization. They are also reasonably flat (above 80 hz), without anything terribly obnoxious in the midrange or treble. They show enough promise that I plan to keep them and see what I can get them to do. Worst case, I plug them into my PC and listen to Philosomatica (internet radio station) using a parametric EQ.


gerG

 

[bangraman]

If you're able to unload the area around the pivot, then this mod will work. Zipties won't unload the area since they're sufficiently elastic to let the cracking continue. If you are going to mod them against the problem, it is advised you glue/wrap a piece of hard rubber to the steel stop pin. You may have to experiment with durometers.


As for removing the pin, I hope you're going to give the A1000 two-sided cables... Otherwise you'll have to be very careful with them!


After lengthy consideration, Cloth Ears considers the A1000 not to be hi-fi in the vein of the W's. They are more like Gratos. Increase voltage swing, up the current and damn the detail!

 

[doobooloo]

gerG - I'm glad to hear that you think they're the best ATs you've heard yet, because I'm very curious about the AT sound, I'll be trying one out sooner or later

bangraman - I think the ziptie, if tied hard enough, will provide significant support on the stress concentration point to greatly reduce the chances of the crack happening. I don't think the ziptie is elastic enough, IMO, to allow the cracking to happen unless there's some serious mishandling...

 

[bangraman]

It won't. If it does, then I'm in the wrong job...


A tightly fitted steel 'ziptie' (they are available in widths probably small enough to fit) will do the job better.


Another alternative: Give the steel pin less leverage to crack the plastic. You can fill in a significant portion of the hole currently fully occupied by the steel pin. Cut the pin down to size so that it's leverage acting on the plastic is greatly reduced. Or something like that.

 

[wallijonn]

in your second picture - there seems to be 3 screws. what's inside that plate?

would an automotive hose clip work? i can see where the type which has to be opened by compressing the fingers, and the type which is adjusted by turning a screw, working. otherwise a stainless steel sleeve in the form of a "C" might work, (also retainer, spring clip, olives, O clips, wormdrive hose clips). again, i have only seen them at automotive stores, but i would think that surgical steel stores may have the part you need.

 

[gerG]

Hi bangraman!

The zip tie is in serious tension. the idea is to hold the outside of the cylinder in compression. Tensile stresses will still be there, but reduced substantially.

Do you have any photos showing where the cracks initiate? Also some teardown shots would be handy if anybody has taken them apart already.

Of course they will get a dual cable (I have a new config in mind). Any idea where I can get a spare left ring? It has a flat spot for cable entry, while the right one is conical all the way around.

As for sound, I agree, they don't sound like the Ws. I consider that good, because the Ws sound just awful to me. I don't think that they sound anything like Grados either, which I also consider a big plus. Again, we are all after different experiences in sound. What I am after is best approximated by the DT931s, but you have to eliminate that obnoxious 10db peak at 5500 hz to get the glare out of them. Then everything comes into focus!


gerG

 

[bangraman]

The cracks initiate at the top of the broken bit in that picture a few posts ago. It occurs along the area directly around the steel pin. Then the ABS (which is quite brittle) starts cracking further. The plastic area around the steel collar retaining the lower earcup assembly in place also starts flaking away at the point of initial damage, because the area depends on the integrity of the plastic around it (which is now cracking).


The cause is definitely the leverage exerted by the steel pin when you put them on. Looking at my friends putting them on, I noticed that people tend to really stretch the phones outwards, whereupon the listener's wrists swing inwards to twist the phone before they put it on the ear. This stretching and twisting is a major part of the stress exerted on the plastic area by the steel pin. The most effective way to limit damage to the are would be to reduce the leverage of the steel pin.


Regarding the sound, I think we have to agree to have a difference of opinion

 

[gerG]

Ouch, I was afraid of that. That pin is the main pivot, right? There are a lot of stresses concentrated in that location. The torque from the headband and from the head pads both get reacted through there. Is there a chance that the lower part of the joint is contacting the upper part (too little clearance) and pressing against it? That won't help.

Disagreement on sound is good, otherwise we all buy the same damned cans and this place gets boring

Thanks for the info.


gerG

 

[bangraman]

No... The steel pin is separate to the pivot.


It's difficult to describe with words, but here goes.


When you look inside that general area above the pivot (just unscrew the screws around the 'limited edition' number plate and take a look inside), there are two steel bits, one which you can't see just yet. One is the main pivot, on which the miniature cartridge bearing spins. The pivot in is topped out by a round steel clip which keeps the earcups fron falling off the phone

The clip rests on part of the general plastic moulding. removing the clip and allowing the earcup to drop down reveals the separate steel stop pin.


The stop pin is separate from the main pivot. It goes quite a long way up the plastic bit above the pivot area, and sticks out below to catch on the lower cast alloy assembly during fore and aft movement, to act as a stop detent. When the pin hits the detents on the lower cast alloy assembly, the pin exerts leverage on the plastic part above. The area where it starts cracking is almost directly beside where the aforementioned round clip rests. Once the crack starts expanding, the integrity of the main pivot mounting area also starts to be degraded.

 

[gerG]

Excellent description, thanks. It also tells me how to get them apart and what to go after. Unfortunately I have to get ready for a trip, so it will have to wait.

Have a great weekend.


gerG

 

[Suedama]

A better, and more elegant solution, is to wrap something like thread or dental floss around the area. The pressure exerted by multiple wraps of thread or the like is incredibly powerful and I'll bet it's much stronger than the plastic band. This is the way the old wooden golf club heads used to be secured to the shaft. It was called "whipping." (If you want it to look nice, the ends of the thread have to be laid down in such a way that the whipping is on top of the thread ends. )