KOSS ESP-950 Thread

[Buddhahacker]

  But first I want to ask them few questions

Try calling them.

 

[s1rrah]

  A word about the infamous squeal. I've had my 950s since 1992, and the squeal has finally reared its ugly head for the first time in all those years. There have been some suggestions here that it occurs due to dust inside the mechanism. So I took a can of Dust-Off compressed air and sprayed it into the perfed metal that sits on the outside of the ear cups. Sure enough, the squeal went away, headphones sound just like they did before.

 
 Every Koss 950 I've either owned or heard .. 

All, at some time "squeal" .. 
 
Welcome to the club.
 
They are briliant sounding headphones, though and perhaps that's why folk still buy them.
 
But the squeal is an issue. For sure ... 

 

[AnalogSavior]

I've read that the squeal is most likely due to dust, but that it may also be related to the bias difference when running them through Stax amps, since it is considered a popular upgrade.  I don't know if this was your case or not, but I find it interesting how universal (and never adequately addressed) this issue is.

 

[Kokomo O]

No, I'm using the stock E90. I think it was only dust. The first time it happened, it was on the left. Since I posted about it, I had it happen on the right, the squeal was the same pitch but somewhat lower volume. Again I took the Dust-Off to it, and again it disappeared.

 

[bobby12]

How much did you all pay for your ESP-950? I'm looking to buy my final headphone during Black Friday and these are high on my list.

I know these come with a lifetime warranty, but can anyone comment on the durability of them?

 

[Kokomo O]

I've had mine for 22 years. I had a problem at one point that somehow resolved itself--for some reason the left channel started misbehaving by playing at a lower level than it should have, and with static. I put the headphones aside for a while (this was before the lifetime warranty) and when I next picked them up a couple of years later, when I heard about the lifetime warranty and thought I'd send them in, there was no problem. Then a few days ago, they caught the famous squeal, which I fixed with compressed air. That's it.

 

[bobby12]

I've had mine for 22 years. I had a problem at one point that somehow resolved itself--for some reason the left channel started misbehaving by playing at a lower level than it should have, and with static. I put the headphones aside for a while (this was before the lifetime warranty) and when I next picked them up a couple of years later, when I heard about the lifetime warranty and thought I'd send them in, there was no problem. Then a few days ago, they caught the famous squeal, which I fixed with compressed air. That's it.

Wow! Your headphones are older than me lol.

These look very promising for the price especially if you factor in the lifetime warranty. Can't wait to try my first eletrostatic headphone

 

[Kokomo O]

Ha, that's pretty funny.
 
I had coveted these ESPs ever since they had the original ones out in the '60s. I don't remember what they cost, but it was too much for the 10 year old me to contemplate. I picked them up for $500 in '92 and it may be the best purchase I ever made.
 
Oh, and about a year ago I replaced the ear pads. Koss charges all of $5 for new ones. 

 

[dwest1023]

I'm on my second pair. I sold the first pair after I got out of high end audio. Got them from a dealer friend for $275. When I got back into high end, had to have another set. Bought a new set for $600. I  think the (50 have the BEST mid-range you can get. Overall sound is Balanced. I love them.

 

[milosz]

I don't think you can clear dust that's inside the driver with compressed air / duster gas.  The drivers are sealed inside dust covers-  in essence, the drivers are inside a plastic bag. The best a spritz from a can of Dust-Off could do would be to blow the dust off the outside of the dust seals.  The squeal is thought to come from very tiny bits of dust that get between the stator and the diaphragm, dust which was likely there since the drivers were made, but somehow migrates into the space between stator and diaphragm. The dust will cause a little corona discharge, which makes the squeal.
 
Maybe by spraying the dust covers you "rattled" the inside of the drivers and shook the dust down from it's squeally location inside the driver into some crevice of the driver framework where it won't squeal.
 
ESP-950's have a lifetime warranty, so if mine ever squeal, I will just send them to Milwaukee....
 
FYI  My 1969 ESP-9's had a squeal, off and on.  Part of the Koss tradition.  Stax has their Stax-fart, Koss has it's squeal.  (I've also heard that Stax 'phones sometimes also develop a squeal, although this is rare.)

 

[TimSchirmer]

These are soooooooooo good. Now that I have a Meridian director, I can just throw it in the ESP-950's box where that battery pack usually goes and I have a really awesome transportable electrostatic rig. Low footprint is important for me as I move to different countries every few years.

 

[Kokomo O]

  I don't think you can clear dust that's inside the driver with compressed air / duster gas.  The drivers are sealed inside dust covers-  in essence, the drivers are inside a plastic bag. The best a spritz from a can of Dust-Off could do would be to blow the dust off the outside of the dust seals.  The squeal is thought to come from very tiny bits of dust that get between the stator and the diaphragm, dust which was likely there since the drivers were made, but somehow migrates into the space between stator and diaphragm. The dust will cause a little corona discharge, which makes the squeal.
 
Maybe by spraying the dust covers you "rattled" the inside of the drivers and shook the dust down from it's squeally location inside the driver into some crevice of the driver framework where it won't squeal.
 
ESP-950's have a lifetime warranty, so if mine ever squeal, I will just send them to Milwaukee....
 
FYI  My 1969 ESP-9's had a squeal, off and on.  Part of the Koss tradition.  Stax has their Stax-fart, Koss has it's squeal.  (I've also heard that Stax 'phones sometimes also develop a squeal, although this is rare.)

You are probably correct. The squeal has reappeared in both sides, and I was going to report this. I have again sprayed them with the compressed air, but I do think I will have to send them in. It's unfortunate, because they're my only headphones, although I do have a pair of IEMs, and good ones, but they're just not the same.

 

[TimSchirmer]

Koss will fix them. It usually takes a few days, but the service is great.

 

[Michgelsen]

  Stax has their Stax-fart, Koss has it's squeal.  (I've also heard that Stax 'phones sometimes also develop a squeal, although this is rare.)

 
Sennheiser HE60 can also have its squeal, as its dust covers aren't completely blocking the smallest dust. Happened to mine, although the squeals come and go. Sometimes you don't hear them for a very long time, or only very briefly.
 
 
On a different note, do not use compressed air or a vacuum cleaner to clean the headphones. You risk tearing the diaphragm.

 

[Rossliew]

Anyone know if i can order the ESP950 with a 230V amp from Koss directly ? Their web shop does not have any option to choose voltage output requirements.