Monsterzero's AKG K240 Sextett buying guide
Buying Sextetts can be tricky, so I will attempt to make it as easy as possible to ID sextetts from other AKG K240s, and also to explain the differences between the three versions.
<<<<<<<<<<This is a Sextett=All silver badging, Holes in headbands.*Note the term "sextett" does not appear anywhere on the HP.

K240 DF=not a sextett

k240 studio=not a sextett

K240 monitor=not a sextett

K240 MK ll= not a sextett
To repeat,must have all silver badging, and have holes in headband. If it doesnt have silver badging and holes in the headband do not even bother.
The K240DF is supposedly closest,but I cannot verify.DF=diffuser..Was used to replace the Sextetts as it was a cheaper way to make. 2022 edit. The DF is quite bass light, similar to the LP Sextett.
There are three versions of the Sextetts, EP, MP, LP. I own all three.
EP=Early Production=bass heavy
MP=Middle Production=medium bass
LP=Late Production=Light bass*some LP actually came with solid headbands.
IMHO the LP doesnt have enough bass for metal,YMMV, etc....I like both the EP and MP for metal, actually prefer the MP, but both will work. The way to ID which version is to look at the color of the six radiators.

Orange=EP sextett=bass heavy

Cream color w/ faint orange on edges=MP sextett=medium bass

Solid white=LP sextett=bass light.
You do not need to disassemble the headphones to ID which version of sextett youre considering. Simply have seller take a photo or two with a flash of inside of cup.
Price: I purchased all three of mine within the last year and didnt pay over 150.00 for any of them. Typically the EP is the most expensive, mostly due to rarity, followed by MP and LP respectively.
I have seen them listed as high as 350.00. Occasionally a pair with original packaging pops up.If that appeals to you then I guess I'd go 200.00 on that but its entirely up to you and your budget.
As Nox mentioned the sound far exceeds the price.They do not sound like 150.00 headphones! The only headphone that I have heard that combines the speed, thump, clarity and forward guitar presentation of the sextett is the original ATH AD2000(non X version), which is actually harder to find than the sextetts. I think the sextett is a more musical headphone than the AD2000, while the 2000s are faster and have a drier sound...both kick ass for metal!
Wear and tear are to be expected on 40+ year old headphones. The elastic headband suspension is one of the first things to go on these HPs, which is a laughably easy fix. If your pair of sextetts sag down while on your head a couple elastic hair ties will remedy this situation.
Amping:I drive mine using vintage receivers, and the combo is great, which isnt surprising since both were made in the same era of audio,when dedicated HP amps and easy to drive HPs didnt exist...so they were kinda made for one another.
Lower tier Schiit amps do not have enough to power these to their fullest capabilities. Hansotek reports great results from his Milo...im suspecting that theres a happy medium somewhere between a Magni,a vintage receiver and a Milo,though.
For further info:
http://www.innerfidelity.com/conten...340-electrostatic-dynamic#Zwha7oZ6gM1TkVxu.97
http://www.head-fi.org/t/243339/akg-k240-sextett-gradod-akg