The Koss ESP950 thread (ESP owners, please contribute! :)
Oct 18, 2007 at 4:03 AM Post #61 of 731
Quote:

Originally Posted by spritzer /img/forum/go_quote.gif
The ESP10 is transformed by a good Stax amp but due to the extreme damping used they sound a lot like the ESP9 and 6.


did you get rid of those two 82pF capacitors and connect the cable directly to the stators? Or just converted the plug?



I am now really curious how good the ESP7/9's can be with higher grade transformers. If I can find a "phones only" set I will probably do a silver recable and see what happens
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Oct 18, 2007 at 4:10 AM Post #62 of 731
Quote:

Originally Posted by edstrelow /img/forum/go_quote.gif
...... my old one which had lost its high frequencies due to some ill-advised modifications.( the story is too long to go into)


How did you manage to do that? Come on, this is the ESP thread, share the story so we can all learn
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Oct 18, 2007 at 4:36 AM Post #63 of 731
Quote:

Originally Posted by AudioCats /img/forum/go_quote.gif
How did you manage to do that? Come on, this is the ESP thread, share the story so we can all learn
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I didn't do it so I don't know what was actually done. An engineer and electronic designer named Bongiorno was adapting the E9 to run off his balanced Class A amp and offered to get rid of the high frequency emphasis at the same time. Seemed like an ok idea but I didn't like the results at all. So I was intrigued that the replacement E-9 has a switch that kind of does the same thing. All I remember was the sight of him ripping things out from the E-9 and cussing the "rat's nest" of wiring in the E-9.

His amp was great but I finally sold it because I couldn't use it with my Polk SDA's which have a common ground.
 
Oct 18, 2007 at 4:57 AM Post #64 of 731
looking at the E9 schematic (found it somewhere in the Stax thread, probably posted by you, or ericj? Can't really remember), he probably took out the EQ from the transformer's primary side (R9, R10 and C15, C16). This EQ circuitry increases treble. The ESP7 has a similar design. (The EQ caps in the E7 box are 4uF/25V Callins non-polar, any idea what the cap value is in the E9?)




.
 
Oct 18, 2007 at 7:40 AM Post #65 of 731
Quote:

Originally Posted by AudioCats /img/forum/go_quote.gif
did you get rid of those two 82pF capacitors and connect the cable directly to the stators? Or just converted the plug?


I removed the caps and the resistors in both cups, rearranged the wiring and had to make an adapter since the wires aren't in any way pin compatible with the Stax standard.

I am now really curious how good the ESP7/9's can be with higher grade transformers. If I can find a "phones only" set I will probably do a silver recable and see what happens
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[/QUOTE]

They do sound pretty nice but the comfort is simply horrible.
 
Oct 18, 2007 at 9:45 PM Post #66 of 731
Quote:

Originally Posted by spritzer /img/forum/go_quote.gif
They do sound pretty nice but the comfort is simply horrible.


I just bent the metal bands back on the ESP 6 and 9's and find they are not uncomfortable. I also use replacement earpads, from some version of a Pro-4 I believe. That may help too.
 
Oct 18, 2007 at 10:37 PM Post #67 of 731
Quote:

Originally Posted by edstrelow /img/forum/go_quote.gif
I just bent the metal bands back on the ESP 6 and 9's and find they are not uncomfortable. I also use replacement earpads, from some version of a Pro-4 I believe. That may help too.


I've bent them too but I need some new pads. There isn't a Koss distributor here and I'm not sure if they are willing to ship to me. The ESP10 is great with my old SR-007 pads as the drivers are just in the right distance. I had to do some mods to increase the thickness of the pads but they work great now.
 
Oct 18, 2007 at 11:20 PM Post #68 of 731
About the ESP6/7/9/10 pads:
if they are not broken/leaking, you can clean them and then inject air into the chamber (from the underside), to fill the pads half way full, so you will get good seal and softness at the same time. I use the needle/syringe from a ink-jet printer cartridges refill kit. After the pads are fill to the desired %, seal/cover the hole with a piece of tape. The air inside the pad is not under any pressure, so a piece of good quality tape is plenty strong enough as a seal.

Properly filled pads are pretty nice, now if we can figure out a way to reduce the ESP6/7/9's weight ....

Have fun
 
Oct 18, 2007 at 11:37 PM Post #69 of 731
Quote:

Originally Posted by AudioCats /img/forum/go_quote.gif
About the ESP6/7/9/10 pads:
if they are not broken/leaking, you can clean them and then inject air into the chamber (from the underside), to fill the pads half way full, so you will get good seal and softness at the same time. I use the needle/syringe from a ink-jet printer cartridges refill kit. After the pads are fill to the desired %, seal/cover the hole with a piece of tape. The air inside the pad is not under any pressure, so a piece of good quality tape is plenty strong enough as a seal.

Properly filled pads are pretty nice, now if we can figure out a way to reduce the ESP6/7/9's weight ....

Have fun



I did a similar experiment on my pads and that worked but they are far from being comfortable. I might be overly spoiled though as I have some of the most comfortable designs ever here.
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Oct 19, 2007 at 12:15 AM Post #70 of 731
Quote:

Originally Posted by spritzer /img/forum/go_quote.gif
I might be overly spoiled though as I have some of the most comfortable designs ever here.
orphsmile.gif



yeah, so you like to put HE90 pads on ESP950 and O2 pads on ESP10, huh
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wait, how much are the O2 pads? are they more then my ESP10 too?
 
Oct 19, 2007 at 4:35 AM Post #73 of 731
In retrospect I didnt like my ESP9 at all. Of course at the time I thought it was the head crippling bees whole damn legs clear up to its bum. But it was still better than any electret I've owned, none of which were stax electrets.

SR-3N > ESP9 imo.
 
Oct 19, 2007 at 7:43 AM Post #74 of 731
Quote:

Originally Posted by AudioCats /img/forum/go_quote.gif
yeah, so you like to put HE90 pads on ESP950 and O2 pads on ESP10, huh
wink.gif


wait, how much are the O2 pads? are they more then my ESP10 too?



75$ last I checked. It's a lot less then the HE90 pads.

Quote:

Originally Posted by AudioCats /img/forum/go_quote.gif
Can somebody provide some info on how the ESP9, when driven by an E9 box, compares with a Stax electrect such as SR-40/80 driven by a transformer box like SRD-4? sound quality wise.
Birgir? Edstrelow? ericj? Anybody?

Thanks!
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I like the Stax phones from the same era a lot more then the ESP9. It's a bit murky and odd mostly due to the closed nature and how they were driven.
 
Oct 19, 2007 at 5:51 PM Post #75 of 731
Quote:

Originally Posted by AudioCats /img/forum/go_quote.gif
How much better are the new foam filled Pro-4 pads, comparing to the original ESP6/7/9 pads? do they provide a good seal?


I don't know if better but certainly no worse and only about $6.00
 

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