More DIY Orthos, and Two AKG K 340 Page 2

Two AKG K 340 from Morphsci
My buddy Morpsci is somewhat unsure of the exact history of these cans, but believes they have been modified by Larry at Headphile. I'm not sure these really belong in the DIY modified section, but hey, they're quite unusual, and I was interested in the sound and measurements of these headphones.

The AKG K 340 was their top-of-the-line headphones back in the early '80s. It is a dual element headphone having both a dynamic driver for the lows, and an electret (permanent charge electrostatic) driver for the highs. It does include a small circuit made up of a few resistors and a transformer. The AKG manual and advertisements make it stunningly unclear as to whether or not it's a crossover between the two elements. (It is, of course.)

Top left is the circuit diagram of the K340; top right is the description in the service manual; bottom two images are from advertisements.

Listening to these headphones was a painful chore. I heard them as confused and edgy. They were also quite difficult to drive. I gave up rather quickly. Sorry morphsci (and philodox). Ah well, that's the fun of the headphone world --- playing with all sorts of unusual gear. Measurements follow.

AKG K 340 sample A

Click on graphs image to download .pdf for closer inspection.

AKG K 340 sample B

Click on graphs image to download .pdf for closer inspection.

Wikiphonia pages for Fostex T20RP, and T30RP.
Headphile AKG modifications page.
AKG K340 advertisement and service manual downloads.


inarc's picture

Thanks for the measurements; I had always been curious about the AKG K340.

morphsci's picture

I'm glad to be able to see some measurements. They do require a bit of power and they are definitely not for everyone (maybe just Me and Philodox).

makiem's picture

WOW... 2 AKG K340.? seriously?