In electronics, “Z” (capital) is the symbol for impedance. Impedance is the load on a power supply measured in ohms. It is the sum of the resistance and capacitive and inductive reactances in an AC circuit (audio circuits have to be powered by DC but then push AC through the speaker drivers or you will hear nothing). Low “z” means low impedance.
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Lol forgot to answer that
okay…what specs does a headphone have to have to use an OTL or SET tube amp successfully?
if I’m following correctly, I think we’re going into the territory where you have headphones that are high impedance, like a 600ohm DT880 or a low impedance headphone like the 36ohm NAD HP50?
perhaps those in the know can share examples of high and low impedance friendly tube amps as well?
Typically you want a high impedance dynamic with otl, but it really depends on the headphones and amp
For reasonable prices that are somewhat available would be the massdrop Eddie current, hagerman labs tuba, cayin ha-1a mk2, mapletree sidewinder, and more of course without getting too deep into either diy or harder to find amps
That being said for planar or very low impedance I would still recommend a hybrid amp instead as they are more flexible with what they sound good with imo, at least sub 1k
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thanks M0N. can you share some examples of headphone types that don’t usually sound good on tube that actually do? you mentioned planar…most of the time you read planar’s don’t like tube amps. is that due to the impedance issue or something else? if something else, I guess that would explain why a hybrid works, being low impedance?
Some good info in there
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Most headphones can be run from a tube but they might preform better on solid state depending on a headphone.
Well a hybrid is only using a tube on the input stage, not using tubes to actually amplify the headphones, so that changes things
okay, but if I understand what I’ve read correctly, using a hybrid still gives you a tubish sound, even though it’s finished and powered by solid state because it’s fed a tube influenced signal?
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I once tried the Sundara on a Bravo V3 amp. i dont think its a hybrid amp and i used a Russian EH 6922 tube. i remember it sounding so good.
Apparently the focal stellias work well on a tube
Eh, people say that alot for most focals but I really don’t see it, I really prefer the focals on a solid state, I really never put mine on a tube outside the utopia. On a hybrid they do well, but on an otl or set it’s eh for me
Yeah. I do find it interesting how there are fewer and fewer high end/audiophile high impedance headphones.
And most of what we use are made for studio use
is my conclusion right about hybrid amps in that the signal is tube pre-amplified which is why it’s tubish when it’s processed solid state?
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You can think of it that way.
But really the better way to think of it is that tubes work usually at higher voltages, and that signal has to be coupled to the relatively low voltage that the headphones need…
You can do that coupling in a number of ways, really Big Ass capacitors (used by OTL amps for the most part), Transformers (the traditional way), or in the case of hybrids using some sort of SS buffer.
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Given that speaker tube amps are dealing with 4 and 8 Ohm loads there’s nothing to stop someone designing a tube amp that works with low impedance headphones, it’s just that the transformers are more expensive, and they need to provide more current, which probably makes them more expensive.
My ha300 has speaker outs as well, and I know of a few headphone amps that have that feature
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what does that have to do with headphones that like tub amps, M0N?
Not one that I have tried. So far I have gone through Loxjie P20, Vali 2 and Zduoo TA-20. The last two are nice amps, but are in no way “tubey”.
I was responding to polygon regarding a tube amp that can drive both headphones and speakers
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ah! Quad has two options as well…the PA One+ for headphones and the VA One+ that’s for speakers but has a headphone out as well.