Electrostatic Headphones

[MLStrand56]

Back in the 70's I bought a pr. of Electostatic Headphones. They sounded Amazing, in the 70's, even with the early 70's low-tech amps.

The Only problem with Electrostat Headphones, is the extremely short headphone cord.

Does Anybody know of a Electrostatic Headphone Extension cord, or is that something I have to have Custom Made?

Is there even an Standardized Electrostatic Headphone standard?

MLStrand56

[jcx]

both Stax and Koss sell specialty construction cable with the correct connectors for their electrostatic headphones

electrostatic headphones are very high impedance, nearly pure capacitance loads of ~100 pF

but any pair of wires has a capacitance between them, depending wire size, insulation thickness, type cables often have 10-30 pF/ft of their own capacitance

electrostatic headphone cable manufacturer's use very specialized cable - small wire, foamed dielectric, relative large spacing - all to minimize the cabling C

even with this special construction the attached cable C can be 30% or more of the headphone C

so if at all avoidable – don't use added cable with electrostatic headphones, it adds substaintially more load to the amplifier
if you must extend, buy the real thing - few can build extension cables with the correct materials

electrostatic headphone amps – particularly some of the published “high end” Class A designs have more energy storage than defibrillators – worst case shock hazard from these could be fatal – another reason not to home brew a set of cables if you have any questions about your knowledge, mechanical skill re high V safety construction requirements – so just buy the manufacturer's extension cable

[stratus46]

I needed to replace the cable on a pair of Koss ESP-9 electrostats. The cable has to be very supple so what to use? I got some Canare L4E5C microphone cable. The only 'gotcha' is you need to Ohm out the white pair and blue pair. For microphone use we just tie the blues together and same for the whites. In headphone use all 4 leads are used independently. MilliVolts kiloVolts what's the difference? Oh yeah, 10^6.

BTW the original cable didn't appear to be anything special though it was a 40 year old design.

G²

[jcx]

talk to Koss? - they have a very impressive repair policy - don't know what they would say about "vintage" pieces though

buying their current ESP-950 extension cable is still probably the best option for getting the wire (even if you don't use the middle lead? are they electret?)

[qusp]

I dont recommend trying to substitute other wires for a stat headphone cable. I make specialty headphone cables as part of my job and do a pretty fine job of it too, but ES cables require not just correct voltage/current handling, but also correct (low) impedance and capacitance. As such the only way I would do one would be either using a replacement cable, or specifying the correct parameters to get a roll of cable made up.

using the Canare would be a very bad idea.

[stratus46]

Originally Posted by jcx

talk to Koss? - they have a very impressive repair policy - don't know what they would say about "vintage" pieces though

buying their current ESP-950 extension cable is still probably the best option for getting the wire (even if you don't use the middle lead? are they electret?)

I talked to Koss about ESP-9s. There is nothing they will do. However, the fluid cushions for the Pro-4AA will fit on ESP-9s but you'll want to warm them up with a hair dryer to get them on the 9s.

G²

[stratus46]

I wish you could see what cable the factory used on the ESP-9s. I don't think you'd be impressed.

G²

[qusp]

the point is, it doesnt matter how spiffy the cable quality is, if the layout and capacitance is wrong, you have made a bad cable. I could throw my most expensive HV rated UPOCC in teflon wire at it and still not get it right without VERY careful construction and measurements

[stratus46]

Originally Posted by qusp

the point is, it doesnt matter how spiffy the cable quality is, if the layout and capacitance is wrong, you have made a bad cable. I could throw my most expensive HV rated UPOCC in teflon wire at it and still not get it right without VERY careful construction and measurements

You misunderstand. I'm not defending the cable I built but the original from the factory wasn't particularly different. That's all.

G²

[jcx]

so the ESP-950 extension cable will be a upgrade