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post #16 of 346
Thread Starter 
Quote:
Originally Posted by spritzer View Post
All electrostatics need dust covers, though Martin Logan in their infinite wisdom decided against it . It's normally a plastic film on the ear side and some fine woven mesh on the other side to lessen any reflections inside the driver.
I thought the headphones don't use dust covers? I didn't notice such feature in ESP7 and ESP10, how about the Stax? I was really surprised when I realize what that film was for ( I first thought somebody messed up and put the diaphragm in front of the stator )
Is the dust cover film supposed to be all wrinkled up like that? Did they make the wrinkles on purpose (to reduce direct sound reflection back to the driver? or other purpose? )


Quote:
Originally Posted by spritzer View Post
The cable is very similar in construction to the one Sennheiser used on the HE's with an outer coat and loose wires inside.
this 950 wire is not loose inside the outter tube. It really is a mini coax without the shield mesh......

Quote:
Originally Posted by spritzer View Post
Btw. Congrats on the new phones. I was going to bid on that set but I'm glad I didn't outbid you.
hehe, to be honest with you, I was worried about that.....
post #17 of 346
hm, I think my extension cable was just teflon coated wire. I used a solder pot to remove the teflon, similar to the Cardas wire...

In the morning I'll link to my ESP950 drivers.

Take care!
post #18 of 346
Thread Starter 
any possibility of some detailed pictures of the extension cable? I wonder if it is using the exact same wire as the headphone cable. Thanks


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post #19 of 346
These phones make a good alternative to the Stax lambdas. And let's face it who else is making electrostatic phones other than Koss and Stax. It is odd that there seem to be more stat speaker manufacturers.

These phones are light but durable, I have had them for over 10 years and had no mechanical problems. Any electronic problems, mainly with the amp, have been fixed under Koss' exemplary warranty.

I also have the ESP6 and ESP9 and they are quite the opposite of the 950 in solidity. But you also get a lot of weight with the earlier models (especially with the ESP6) and some pretty tight clamping on the head.

If you think $1,000.00 SRP is high, their initial price was closer to $2,000.00. Fortunately you can regularly get the phones and amp new for about $600.00

There appears to be some consensus among those who have tried them that the phones are better than the amp that comes with them. Certainly I can confirm that they sound better from a Stax amp, than the supplied Koss amp and I assume they would sound good from a Stax transformer. Too bad that Koss doesn't just sell the phones with Stax wiring and without the amp.

http://www.head-fi.org/forums/showthread.php?t=258802

http://www.head-fi.org/forums/showthread.php?t=260041

The Koss amp can be improved with a better outboard power supply than the walwart it comes with. But you really need a better amp to get the best from these.

Now if I could only get the ESP9 to work properly on a Stax amp.
post #20 of 346
Thread Starter 
edstrelow, can the ESP9/Stax amp situation be due to the high capacitance cable on the ESP9? was the ESP9 recabled to Stax ribbon when you did the stax plug conversion?


By the way, just ran aross a SR-40 auction on ebay and the cable look exactly (at least on the outside) like the ESP950's cable, except the SR-40 only use 4 wires and has a Stax plug on it....
post #21 of 346
Quote:
Originally Posted by AudioCats View Post
edstrelow, can the ESP9/Stax amp situation be due to the high capacitance cable on the ESP9? was the ESP9 recabled to Stax ribbon when you did the stax plug conversion?


...
Interesting suggestion. Obviously I got rid of the Koss circuit boards in the ESP9 earcups and drove the transducers directly from the Stax amp, but I didn't change the cable.
post #22 of 346
Thread Starter 

Recabling the ESP950?

I just measured one of my twisted pair silver/teflon IC cable, the inter-wire capacitance of a 4' cable is 40pF (26ga silver, 8mil teflon), which is only 4pF higher than the stock 950 cable's adjacent wire capacitance. Am thinking about a silver recable right now

Now I am not saying the ESP950 cable (36pf adjacent capacitance for 4' length) is bad, it still has much lower capacitance than the ESP10's coil cable (10' coil cable has adjacent wire capacitance of 186pF, that is 74pF for a 4' length).

Must buy more silver!
post #23 of 346
Quote:
Originally Posted by AudioCats View Post
I thought the headphones don't use dust covers? I didn't notice such feature in ESP7 and ESP10, how about the Stax? I was really surprised when I realize what that film was for ( I first thought somebody messed up and put the diaphragm in front of the stator )
Is the dust cover film supposed to be all wrinkled up like that? Did they make the wrinkles on purpose (to reduce direct sound reflection back to the driver? or other purpose? )
The dustcover is inside the driver on the old ESP's acting as an insulator as well. It isn't a bad idea but Stax has always placed it away from the stators.

The dustcover isn't stretched to minimize reflections.

Quote:
Originally Posted by AudioCats View Post
this 950 wire is not loose inside the outter tube. It really is a mini coax without the shield mesh......
It's not loose in the Sennheiser cable either but the Stax wires aren't built like this. They only use the outer insulation.

Quote:
Originally Posted by AudioCats View Post
hehe, to be honest with you, I was worried about that.....
I figured I'd wait a bit longer. I've got to stop buying all this stuff.
post #24 of 346
As a foil to this predominantly technical discussion of the ESP950 I'll add I recently acquired these with a Stax termination as a 'back up' to my HE60s. I've found that although they're not as long-term comfortable as the HE60s (they remind me of the excessive warmth of the Lambda enclosures), their SQ is quite pleasant and enjoyable (though not at the HE60 level of resolution that I've become accustomed to). Although they do perform with a surprisingly more even/balanced response across the spectrum from my bedside SRD-XPro than the HE60s. The HE60s are still the preference from the Woo and EA-4.

All of this is over a short timeframe of ownership (and therefore listening) though. So I'll update this thread (if it truly does blossom into a Stax Thread competitor) after a much longer time with the Koss.

However I will also say I haven't tried them with their own amp yet (I've read the impressions of others and as mine are Stax terminated and I've plenty of Stax ended amplification around I simply haven't made the time/bothered to give them a try through their own amp ). And, of course, the EA-4 Koss outlet is McAllister's own unique 'Koss' plug end, not the true Koss plug .

They are at a performance level, though, that suits my needs as a 'back up' (in case the HE60s ever need to leave for repair) and as an alternate listening experience. Which is interesting because the housing is the only drawback for me - they won't get use during the summer over here in Australia - too sweaty over too short a time - but they'll serve well during cooler times. Sort of like my Normal Lambdas that I definitely regret moving on now (although I'm sure others will come up if I really end up missing them too much - they were just a great winter phone for my bedside rig when I was sick - better than having the SR-001s in the ears). So the Koss's will serve well in those circs, too I think.

O.k., enough personal impressions - back to you guys to talk technical aspects/dissection of materials/etc.
post #25 of 346
Thread Starter 
Quote:
Originally Posted by spritzer View Post
The dustcover is inside the driver on the old ESP's acting as an insulator as well. It isn't a bad idea but Stax has always placed it away from the stators.
any picture of what the Stax dust cover look like? very curious.... I got some small piece Mylar coming, am thinking about building some DIY drivers somewhere down the road
post #26 of 346
Thread Starter 
Quote:
Originally Posted by webbie64 View Post
As a foil to this predominantly technical discussion of the ESP950 I'll add I recently acquired these with a Stax termination as a 'back up' to my HE60s. I've found that although they're not as long-term comfortable as the HE60s (they remind me of the excessive warmth of the Lambda enclosures), their SQ is quite pleasant and enjoyable (though not at the HE60 level of resolution that I've become accustomed to). Although they do perform with a surprisingly more even/balanced response across the spectrum from my bedside SRD-XPro than the HE60s. The HE60s are still the preference from the Woo and EA-4.

All of this is over a short timeframe of ownership (and therefore listening) though. So I'll update this thread (if it truly does blossom into a Stax Thread competitor) after a much longer time with the Koss.

However I will also say I haven't tried them with their own amp yet (I've read the impressions of others and as mine are Stax terminated and I've plenty of Stax ended amplification around I simply haven't made the time/bothered to give them a try through their own amp ). And, of course, the EA-4 Koss outlet is McAllister's own unique 'Koss' plug end, not the true Koss plug .

They are at a performance level, though, that suits my needs as a 'back up' (in case the HE60s ever need to leave for repair) and as an alternate listening experience. Which is interesting because the housing is the only drawback for me - they won't get use during the summer over here in Australia - too sweaty over too short a time - but they'll serve well during cooler times. Sort of like my Normal Lambdas that I definitely regret moving on now (although I'm sure others will come up if I really end up missing them too much - they were just a great winter phone for my bedside rig when I was sick - better than having the SR-001s in the ears). So the Koss's will serve well in those circs, too I think.

O.k., enough personal impressions - back to you guys to talk technical aspects/dissection of materials/etc.
cool! back up for HE60 eh?

Impressions/ personal experiences are alway welcome......
post #27 of 346
Thread Starter 
One question about the E90's factory wallwart: what is the output rating of it? and does anybody know what its open/no-load voltage is?

Since the E90 supposedly uses an op-amp as current follower inside, I wonder what the max operating PS voltage is for that opamp..... maybe it is possible to use power supply voltage higher than 12V and get even better performence.

Not that I have a E90, just curious....
post #28 of 346
Thanks a lot for sharing all those pictures.
The ESP950 looks like a nice pair of cans, which from what I hear are comparable to the Stax Lambda's when it comes to sound quality.

Finish the transformer box, and post some impression...
post #29 of 346
Quote:
Originally Posted by AudioCats View Post
any picture of what the Stax dust cover look like? very curious.... I got some small piece Mylar coming, am thinking about building some DIY drivers somewhere down the road
Here is a bad picture of the SR-007. It isn't mylar that is used for dust covers but PVC. There is no stretching involved so why pay extra for a material that is terribly noisy if not stretched.
post #30 of 346
Thread Starter 
Thanks for the O2 picture, but I am not sure I saw the dust cover film..... is it the haze on top of the gold disc?



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