FS: Koss ESP9 electrostatic headphones (in need of service)

[Lawrence001]

I bought these ages ago on a whim aware that over time the energiser tends to need servicing, which generally involves replacing the caps at least, and these are no exception. They start off quiet with some farting noise on one channel on bass notes, which tends to subside as the energiser charges up (which takes a while), but can still come and go occasionally with quiet passages. I believe this will be aging components in the active bias circuit in the box that need replacing.

The foam under the headband deteriorated as usual and had to be removed. It can be replaced with something I'm sure The liquid filled ear pads dried out and have been replaced with some soft foam ones.

Having said all that, they sound really nice when they are fired up and working well, rivalling some very expensive modern planar headphones IMHO.

It's a shame to keep them boxed up forever as I'll never get round to it, so I'm seeing if anyone is interested in restoring them. They really are worth it, these are still world class headphones all these years later. In fact it's hard to believe when you hear most vintage headphones that a model existed back then that sounds as good as some of the best modern ones.

So £50 collected from North London or plus postage.

[Lawrence001]

Bump for these if anyone wants a little project for 2021.

[M6NTL]

Hi Lawrence, I fancy having a play with these - I owned two pairs with a Dual Energiser back in the early ‘80s - they were only bettered by the AKG K1000s I replaced them with.
Can you please get a postage cost to Leicester for me?
Cheers, Mark.


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[Lawrence001]

Sure Mark leave it with me

[Lawrence001]

Actually I'm pretty sure I can get Parcelforce for a flat £12 if that's any use to you?

[M6NTL]

Excellent,
That sounds great!

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[Lawrence001]

Great I'll PM details, can get off next week.

[M6NTL]

Hi Lawrence,
I've PayPal sent the dosh - can't seem to get to the PMs for some reason so I'll email you with my address. Cheers.

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[Lawrence001]

Cheers now sold and hopefully singing well again soon

[M6NTL]

Thank you!

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