How much power is needed to drive HD6xx to its full potential?

I have read that hd6xx scales better with more power. While looking at specs of Amps, how much power (in milliwatts at 300ohms) should i consider adequate to drive hd6xx to its full potential ? And many amps dont mention power output at 300 ohms. In that case, what should be the output at 32 ohms ? There are usually conflicting reviews about ‘the not so powerful amps’ where few people find the power adequate, while others dont. Thanks.

"Full Potential" is such a subjective thing... I've powered my HD650 with 6 different desktop amps, two LG V series phones, 3 AV Receivers, 2 portable amps and 3 different DAP's. I prefer it with my Cayin iHA-6 or THX 789 but that doesn't mean it sounds bad on the other options. The HD650 can get 100db with 1 mW but one must take into account the impedance curve of the headphone as well. The HD650 is 300 ohm nominal but spikes to over 500 ohms at around 85Hz meaning if the amplifier can't swing 1mW into 500+ ohms it's gonna sound weak. If you are buying the HD6XX to listen out of a phone (other than LG V series) it won't be great but there are a ton of options below $200 that will give you most of what that headphone has to offer.
Oct 2, 2020
Right, for the HD6XX, the 500ohm spikes around 80-100Hz (according to, so the cans will loose a bit of fullness if the amp cannot swing that amount of power at 500+ ohms.
Aug 26, 2020
AFAIK the best value you can get to run HD650 or HD6XX out of is a Schiit Fulla. They usually have some on B-stock, too. Been running a Fulla 2 for around 3-4 years now, only recently felt the need to upgrade. I think they're up to the 3rd gen of the Fulla now, and you can get it in black if you're a gAMER
Aug 24, 2020
I would look for reviews about the product and find out in the recommendations of the actual users/owners. That your best bet!
Aug 28, 2020
This. Most pro reviews will mention the various power outputs. Though I can't say I've seen many manufacturers not list power @ 300 or even 600ohms as they know plenty of aficionados have cans with those impedances. And if the manufacturers don't, a review or thread on that amp will inevitably have someone do the measurements and report back. Unless you're looking at a very niche brand or something; but sites like Audio Science Review does plenty of measurements, among others.
Sep 1, 2020
You are absolutely right, thanks for the sound advice !!
Aug 24, 2020
Good question, but nobody will answer you. If they do! you will enlightened and you wont waste your money buying various products.