How much does the seller want for his K340? I'd be cautious because it's an old headphone that uses a crossover for it's 2-way electrostatic/dynamic driver array and the capacitors are known to have leaked by now. I think K340 is worth owning if you know what you're doing regardless of what you have to power it. My first choice would be a tube amplifier. I like the warmth it brings to the table with AKG headphones of this particular era.
