[Reticuli2]

running a 3.5mm male to 3.5mm male cable interconnect from the front 3.5 to my waist band eliminates the hum.
 
Did I screw something up before when I sent sound through both the front and rear inputs and it was garbled?

 

[manywelps]

I think it's a plain ground loop.  I can touch the bifrost it's connected to, and it goes away.
 
When I turn on a Wii U on the same circuit (connected to bifrost via optical), the hum gets way worse.  Touch ANY ground will stop it.  (Bifrost case, either of the L/R grounds on the RCA connections, or the front 3.5mm.)

 

[manywelps]

Yeah it was a ground loop, a Hum Eliminator solved that problem right up.
 
Speaking of which, are there better pads for 950's?  Like velour or leather?  The stock pads don't breath at all...

 

[Magick Man]

I need a new extension cable for my ESP950s and Koss is giving me the runaround (and being pretty obnoxious about it, crappy CS from them). Where can I buy one?

 

[Starkeyg]

Hello all,
 
Have searched quite a bit and am still looking to find a schematic of the ESP 950 power unit.  Does anyone have a copy to look at?
 
I did add some Os-Con caps across the power input connector and that did help the bass some.  Increasing it over 100 uf though did not improve things any.   Getting a local storage for current demand at the direct power input negates most of the resistance and inductance the long power cable gives as well as any resistance in the power connector.  So FWIW about 100uf seems to be about the max that makes any improvement as far a I can tell.  Costs very little and likely gives all the same results a larger power supply would as the current power supply is only putting out about 1/3 of what it is rated at for my listening levels. 
 
Anyway, anyone have a copy of the schematics they could share?
 
Regards,
Greg 

 

[Magick Man]

I need a new extension cable for my ESP950s and Koss is giving me the runaround (and being pretty obnoxious about it, crappy CS from them). Where can I buy one?

They contacted me to tell me that they have the cables in stock again, so I ordered a couple, and they apologized for being wankers. So it's all good.

 

[Mr.Sneis]

Figure this is a good a place as any to post something about these ESP-9's I've been working on.  I was lucky to snag an affordable pair from another HF'er.  Well the lucky part remains to be seen as these will remain a work in progress for now. 
 
These were bone stock and even with new Pro 4AA pads they did not work very well; they clipped/overloaded like mad and very iffy sound from both channels.  I have a few different amps that indeed let me see that they were in overload condition when anything resembling bass came into the picture.
 
I've sunk quite a bit of time into these so far and still have a long ways to go in the rehab/refurb process.

-Cleaned the old foam and replaced with hand cut random packaging foams I had lying around - I thought this would fix everything but after about three attempts not even close!
 

 

-Cleaned the circuit board contacts on each cup - This seemed to help slightly

-Replaced the capacitors and resistors on each cup - This also seemed to help slightly
 


 
 

-Disassemble and replace the wires that run through the headband with a soldered connection - This required a ton of work and glue but I think it may have at least cleared up the channel imbalance.
 

 
 
In their somewhat current working state at moderate listening levels these actually sound very good, the fit is awful however ~ I suspect the headband arc is ever slightly out of round or my head shape is just too weird. When you get to louder volumes they still clip and lose steam, the threshold for this is what I would consider only moderate listening level.
 
Next up I will tackle the E9 for replacement of as many components as I can, it's an absolute nightmare but hopefully it will solve or lessen the clipping issues. 
 

 
 
Parts seem to be very high voltage ratings 1000v and 1500v for many of them which makes finding modern replacements a bit of a challenge and awkward for fitment.  I think it was mentioned by Spritzer previously the bias is around 400v.  The diodes from the manual list Solitron MV16A and a 1R175A Zener which is not too helpful.  I have gone with SF1600 for the diodes and 1N5955BRLG for the Zeners, hopefully I won't be blowing anything up!

 

[timb5881]

Having owned my ESP-950 phones since about 1993, I have always wondered why no one ever made a third party amp for it. There are most likely several thousand 950 units out there. Or the more interesting option would be a third party amp that had sockets for all the Stax (both pin outs 5 and 6), and all of the Koss models. Just add a selector switch for all the required bias's for the various models. I know there are a few other manufactures of electrostatic phones, but not many of the headphones are really availble ( I really do not think there all that many Orpheus headphones availble)

 

[DegenerateSlob]

Hey guys,

This morning I sat down to find my ESP950s have a slight buzzing coming from the left ear piece. This occurs even when it isn't plugged into a source, just the electrifier. I received these back from KOSS only two months ago, while having bought them about four months ago and am not eager to relive that experience, especially given that I just put after market earcups on them. Wondering if this type of problem is usually from the electrifier, or from the phones themselves. Thanks!

 

[HatIsMyFriend]

Is there any other electrostat on the market that one might compare the ESP950 to? I'm unable to find a demo locally at the moment, but they do look interesting.

 

[axtran]

Is there any other electrostat on the market that one might compare the ESP950 to? I'm unable to find a demo locally at the moment, but they do look interesting.

I own both of these, but I think my Stax SR-407 is pretty similar to my Koss ESP-950. I do like the ESP-950 sound better though.

 

[tiamat556]

massdrop is gonna release the esp95x for 500 USD soon

https://www.massdrop.com/buy/massdr...leCampaignId=394582&iterableTemplateId=565561

 

[axtran]

Awesome collaboration product! I suspect it'll sound the same... which is a steal for everyone to get to have one in their collection. Doesn't beat my price that I got mine for though

 

[timb5881]

Awesome collaboration product! I suspect it'll sound the same... which is a steal for everyone to get to have one in their collection. Doesn't beat my price that I got mine for though

I think I paid about $459 for mine, with case and battery pack new in 1992

 

[barondla]

Just joined the Massdrop for these. Should be interesting.