How do Koss ESP/9 electrostatics stack up?

[tmblack]

Looking at vintage electrostatics headphones like the Koss ESP/6 and 9 and Marantz.
They resemble electrostatic speakers in the use of step up audio transformers.
They are bulky and probably need servicing.

How do they sound compared to modern headphones?
Like AKG 240s, Sennheiser HD600, or whichever ..... headphones?

 

[jcx]

the ESP950 is current production and comes with a ss amp - the amp is despised on Head-Fi but that could be the cheap plastic box and tiny split knob volume pot - I wonder how "audiophiles" would rate it in a 20 lb Al box with a 2"+ knob?

quality step-up xfmr is surprisingly hard for headphones - the ridiculously low power requirement doesn't save much core material when you need huge Lm to support 500+ Vrms at 20 Hz

 

[tmblack]

The ESP/9 have fairly good xfmrs, the leakage inductance of the transformer might be a concern, many modern headphones roll off the low end below 100Hz but not these ones.
How do the ESP950 compare with previous models?

 

[jcx]

the 950 are the only es I've owned

you can get your fill (or more) of subjective opinion at Head-Fi.org - Headphone forums and reviews for audiophiles

I believe the ESP/950 headphone is considered competitive with Stax (higher end Lambdas?) when driven from a "better" amp

 

[chinsettawong]

I only have a chance to compare ESP/9 with my DIY electrostatic headphones. Even though ESP/9 sounds pretty nice, I feel that my DIY headphones with open back sound more natural. The bass response on ESP/9 isn't as good either.

However, if you can get them cheaply, they are not bad at all.

Wachara C.

 

[imfree707]

Bad Pun

Looking at vintage electrostatics headphones like the Koss ESP/6 and 9 and Marantz.
They resemble electrostatic speakers in the use of step up audio transformers.
They are bulky and probably need servicing.

How do they sound compared to modern headphones?
Like AKG 240s, Sennheiser HD600, or whichever ..... headphones?

I only posted this to make a bad pun and it may/may not be true. They don't stack up to Stax. This pair, $2200

 

[banjo4ever]

I have had a chance to recently audition Koss in Singapore. I would compare them to My AKG 702. I found the mid to a bit harsh, the soundstage and space was good. The bass was thin. Good for vocals.
The build quality was not good. Koss offers a life time warranty on the product. I was also not inspired by the looks.

 

[tmblack]

Is there a source for the 5 pin connector?
Looks the same as the STAX connector.

 

[tmblack]

I found the Koss ESP/9 to be smooth sounding, rolled off compared to modern dynamics.
There shouldn't be any harshness, perhaps the capacitors need to be changed from ceramics to polypropylene in the audio path.
I would like to try them with a tube headphone amp but that would require DIY or modification.

 

[speaker dave]

I had ESP/9 and found them neutral and wide range, probably better fidelity than my Stax SR3. But the weight and the pressure was way over the top.

I still have the SR3 but traded the ESP/9s away.

David S.

 

[starkeyg]

Hi,

ESP9 is quite a bit older model than the ESP950. Really doubt reviews of the ESP9 will tell you much about the newer model.

I have the ESP950s and added a better power supply for the amp (about $35). Work pretty darn good for the price IMHO. Can sometimes find them on sale for ~ $650.00. List is ~$1000.00 but if register for updates from the Koss website, you can instantly get a discount getting the price down to about $850.

Certainly there are better out there. But by the time you spend $1600.00 or more for STAX phones and another $900 or more for a amp for them you are in a different price range.

Build quality is fair, nothing impressive or pretty, but engineered well and works fine, also has a lifetime repair guarantee. If you need pretty cases, exotic wood and such then these are not for you. IMHO

Regards,
Greg