Like many people on this site, I have trouble matching the tech specs for a headphone to the published specs of amplifiers. I simply have no idea how to tell which headphone will sound good with which amp. One member here informed me that I was being ignorant and should just compare the output impedance graphs for an amp with the impedance graphs for a headphone. So where do I get these then? I've looked at the websites of several amp manufacturers and never seen an output impedance graph. In fact, most headamp sites don't offer much information about power either. They just say maximum power is something like "one watt." They don't even say whether it's one watt at 600 ohms or one watt at 32 ohms. Basically I need some more information about how to match headphones to amps, and yes I did use the search function. If anybody could help me out on this I would appreciate it. It's only 5 minutes of your time to make a post but your info will really help me save money!
Amplifier output impedence graphs
- Thread starter tvrboy
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GaryJW
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I've heard this before but do not understand it. I would expect a decent amp to be either very low impedance (i.e. tending to perfect voltage source) or very high impedance (tending to perfect current source). There is apparently some standard for 120ohm o/p impedance for headphone jacks but see few amps that claim to meet this (I would assume that this is there by design to prevent damage from shorts as the jack plug is inserted/removed).
It would be very difficult to match impedance with headphones anyhow as they will be substantially reactive (i.e. impedance derived from the dynamic and magnetic behaviour rather than resistance).
There is an adage that for maximum power transfer that the impedance of the source should be the same as the target. However, this is useful either in high frequency applications with reactive impedance or when considering maximum power from a battery. In the latter case (battery) this is an extreme case and if applied to most batteries would destroy them (since as much power is dissipated in the battery as the load). Batteries normally feed impedances that are much higher than own (which leads to efficient energy transfer - most of the power is dissipated then in the load, not in heating the battery). I think that this would be very missapplied in the headphone case (i.e. looking for a 32ohm o/p impedance amp for denon ah-d2000s or 600ohm for senn hd-650s)..
In general (for solid state amps) I would expect that the amp impedance to be very much lower than the headphone impedance. Worth checking in the case of low impedance headphones.
It would be very difficult to match impedance with headphones anyhow as they will be substantially reactive (i.e. impedance derived from the dynamic and magnetic behaviour rather than resistance).
There is an adage that for maximum power transfer that the impedance of the source should be the same as the target. However, this is useful either in high frequency applications with reactive impedance or when considering maximum power from a battery. In the latter case (battery) this is an extreme case and if applied to most batteries would destroy them (since as much power is dissipated in the battery as the load). Batteries normally feed impedances that are much higher than own (which leads to efficient energy transfer - most of the power is dissipated then in the load, not in heating the battery). I think that this would be very missapplied in the headphone case (i.e. looking for a 32ohm o/p impedance amp for denon ah-d2000s or 600ohm for senn hd-650s)..
In general (for solid state amps) I would expect that the amp impedance to be very much lower than the headphone impedance. Worth checking in the case of low impedance headphones.
Anybody else? I know there are people around here who can answer this...
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