[6BQ5]

Has anyone tried to run their Hifiman HE-6 headphones from the speaker taps of their RM10?

These are unlike other headphones out there (orthodynamic) and are the most inefficient headphones currently in production. Most people have found they sound very poor when trying to use them from a regular headphone jack, even from a high quality headphone amplifier because they are so inefficient. So people are reporting they are running these off of 100 Watt solid-state amp speaker taps with excellent results.

The recommendation by Hifiman is that the amp should ideally output 5 to 12 watts into a 50 Ohm load. 

Before going down this path, I'm curious how well the RM10 can handle such a load off the 8 Ohm taps and how much wattage it would produce. Would the distortion be higher?

[Roger A. Modjeski]

Hard to believe any headphone can absorb that kind of power. I wonder if they want a 5-12 watt amp into 8 ohms. Remember most headphone amps are in the milli-watt range and often with limited voltage and current.

In any event the RM-10 has a high enough damping factor to consider it a voltage source. Power is equal to voltage squared over impedance. Since the voltage is constant the power is just the ratio 8 ohms/50 ohms or about 6 watts. Try it out on the 8 ohm tap.

[6BQ5]

Thanks for the information Roger.

Yes, the HE-6 is a beast. It is one of the new generation of uber headphones that everyone has been talking about the past year. Rather than dynamic drivers, they use planar technology similar to what you find in Magnepan speakers. (Some) people are giving up on their Stax headphones to go down the orthodynamic route because they feel there is more "body" to the sound. However, they are extremely inefficient though with an almost ruler flat 50 Ohm impedance load. They can get loud with low power amps, but will lack bass and sound flat and congested.

I have not purchased them yet, but before taking the plunge, I wanted to be sure if I could drive them adequately. Some additional information here:
http://www.head-fi.org/t/529873/amps-that-can-drive-the-hifiman-he-6-planar-headphones