[obobskivich]

I don't care whether Grados are accurate, or balanced, per se - they just sound so much more like real live music than anything else I've tried.  Like tube amps, they present a sound of realism that few alternatives are able to present, though those alternatives may be more accurate, or balanced.  A little distortion "is a good thing."  And they are also as clear and detailed as anything else I've tried, or moreso than most - though the Stax SR507's are close - just not quite as much drive, PRAT, and bass.

I'd agree with this. I think the ESP/950 are the "other side of the coin" so to speak.

 

[Mad Dude]

I currently have some issues with the E90, and I'm wondering if anyone else is experiencing the same problem:
Is anyone else using the E90 energizer along with another (headphone-) amp from the same source? If yes, have you ever noticed any issues?
 
I have connected both the E90 and the Meier Concerto (via Y-splitter) to my CD player since I've bought the ESP-950. So far, I've never had any problems with this, or at least I never noticed any. However, I recently bought a HD800, and noticed some distortion when listening to it - very much like clipping on a badly mastered recording - even on classical recordings, which definetly should not exhibit such issues. I also noticed that whenever I compared the HD800 to the ESP-950, the problem was gone. I then discovered that apparently the E90 is causing this distortion, but only while it's switched off, even with the power cable disconnected. Switched on, the distortion immediately disappears. Weird!
I suppose this distortion (?) was always present but I've never noticed it with the HD600, whereas the HD800 makes it quite apparent.
 
 
On another note, I'm beginning to see why the ESP-950 is not quite as popular is it probably should be - the often talked about build quality is an issue, I have to admit. I often feel that the ESP-950 has to be treated like a raw egg. The squealing issue, which returns every couple of days, is also annoying. Also, the pleather earpads make them rather uncomfortable to wear (at least now, with summer temperatures). It's a real shame, sound-wise it is very close to what I'd consider perfection...
(In short, my HD600 is once again my go-to headphone

)

 

[kevin gilmore]

diode clamps on the inputs to the power supply. When you turn it off, it limits
the input signal to 1.4v peak to peak.

 

[Mad Dude]

Thanks for the reply Kevin, but please forgive me if I'm being stupid - do you mean that the input voltage should be limited in order to avoid the distortion issue, or that the voltage is being limited by the E90 and as a result produces the distortion?

 

[kevin gilmore]

The voltage is being limited by the e90 when the power is off. If you can turn voltage driving the e90 a bunch
it won't clip.  Much better would be to just disconnect it, as it is still a fairly low impedance load.

 

[obobskivich]

My two cents:

My E/90 shares a splitter with some speakers, and I have no trouble. They're relatively sensitive, but still, have never had a problem. It also doesn't bother the up-stream processor.

If you need to switch between them though, as this sounds like an issue, an A/B toggle would be the simple answer.

 

[charliex]

Quote:

Get new pads, they might fix most or all of what you're experiencing.
http://www.koss.com/en/products/accessories/ESP950_Ear_Cushion__ESP950_Ear_Cushion
Yeah, they really are just $5 each.

 
ALL their pads are $5.00 a set and there are many styles and sizes to choose from - some could probably work well
with other brand headphones such as Beyerdynamic, Sennheiser etc.. Could be a discovery here!  They also have a
number of portable headphone cases and more.  And to top that off,shipping is free on all orders over $7.99

 

[Mad Dude]

Alright, it seems like I'll need a switch to toggle between the E90 and any other amps. Thanks again for the replies!
The distortion really is very faint, and I've never noticed anything with the HD600 or the Stax SR404.

 

[singh]

@ mad dude , you should get a replacement for the ESP950 , the squealing issue for me vanished after a few days .
 
@charliex , Only one Pad ( on the Koss website ) is compatible with EP950. More earpad materials would be welcome though. But comfort wise am quite happy with the ESP950

 

[milosz]

 
 
On another note, I'm beginning to see why the ESP-950 is not quite as popular is it probably should be - the often talked about build quality is an issue, I have to admit. I often feel that the ESP-950 has to be treated like a raw egg. The squealing issue, which returns every couple of days, is also annoying. Also, the pleather earpads make them rather uncomfortable to wear (at least now, with summer temperatures). It's a real shame, sound-wise it is very close to what I'd consider perfection...
(In short, my HD600 is once again my go-to headphone

)

 
If they squeal, send 'em back to Koss.  Lifetime warranty.  They should not squeal.  Mine don't.

 

[BoogieWoogie]

I got a esp950 setup from US and because of the voltage I need to get a transformer. Any one knows what the specs need to be ?

 

[jcx]

the E/90 is powered by a 9 Vdc 1 A wall wart, center positive, line rating 15 W
 
mine measures 14 Vdc open - clearly not regulated - must accept a range since it also uses 6 cell battery pack which could be as low as 7.2 V with rechargable 1.2 V cells
 
some have sugested using regulated DC supply - the E/90 spec sheet claims 320 mA typical current draw

 

[BoogieWoogie]

Thanks its working. When I fire it up it blinks red for 2 seconds and then fixes a green light, this is normal ?

 

[obobskivich]

Thanks its working. When I fire it up it blinks red for 2 seconds and then fixes a green light, this is normal ?

Mine does not blink, but it does start red and then fixes green. The manual says that is normal. I forget what blinking means.

From the manual wrt blinking:

LED Does Not Light Or Is A Solid Red Color -
* Check battery power. The LED on the E/90 will flash red as batteries run down. The LED will become a solid red when batteries are dead. If battery voltage is too low the LED will not come on.

 

[Mad Dude]

Quote:

Thanks its working. When I fire it up it blinks red for 2 seconds and then fixes a green light, this is normal ?

 
Mine does the same, blinks red for a few seconds and then turns green. I suppose it's normal behaviour.