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Post by hower on May 12, 2006 9:34:49 GMT
When choosing a headphone, how do we tell if it is easy to drive or not?
Which specification should I look at? How to I tell and compare?
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Post by PinkFloyd on May 12, 2006 9:50:05 GMT
When choosing a headphone, how do we tell if it is easy to drive or not? Which specification should I look at? How to I tell and compare? Generally the lower the impedance the easier the phones are to drive so a 32ohm 'phone should be easier to drive than a 600ohm 'phone. Also look @ the sensitivity of the phone which is measured in db.
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Post by hower on May 12, 2006 10:31:02 GMT
Ok, so does that mean my X-CAN V3 will find it easier to drive a GRADO SR-1 (32ohm) than to drive my present Beyerdynamic DT-931 (250ohms) or even a Sennheiser DT990 (300ohms)?
So, if I change to a SR-1, what benefit will I get? Louder music?
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on May 12, 2006 17:26:25 GMT
as a loose rule mid to high impedance cans need voltage gain to move the diaphragms of the headphones,low impedance headphones current gain because it takes a lot of current to move a low impedance (like a loudspeaker which is usually from 4-16 0hms).
The difficulty in designing a "universal" headphone amps is the requirments can range from high sensitivity low impedance headphones needing low voltage gain but high current gain to medium impedance low sensitivity headphones that need a lot of voltage drive to produce the same volume levels.
what you end up with many times is either a headphone amp designed to drive say Sennheiser headphones with way too much gain for the high sensitivity headphones like Grados and forces you to always use the volume control at the bottom end where L/R tracking is at its worst or a headphone amp wityh low voltage gain that is always at the "full volume" level and still needing more drive for dynamics.
My opinion is a headphone amp needs either be labeled "headphone specific",that is identify the headphones it not only was designed to drive but which cans were used in the evaluation/design stage OR have a high/med/low gain control so you can match the amp to the application and even then you have to make comprimises unless you have separate output topologies for the specific use of.
but that is an "ultimate" approach and would be mostly unworkable in a commercial design due to either cost limitations (hitting a price point that sells to a wide audience rather than just those with deep pockets) or carrying two versions of the same amp which is never smart if you want to move stock and/or avoid one version sitting depending on market popularity of one headphone over another.
The good news is a solid state opamp based headphone amp is easily designed to have a front end with good voltage gain plus a gain adjust switch mated to a discrete or monolithic current gain stage with high voltage handling OR a tube based stage with transformer coupling that has taps for various impedances (adds a lot to the cost and why you don't often see it).
The way a transformer works is it presents a high impedance to the gain stage for easy driving (32-600 ohms is a real bitch for tubes) and depending on which "tap" is chosen will perform self attenuation of the voltage gain depending on the step down ratio making the actual gain stage universal as long as it has a high voltage and current drive capability (5687,6C45,etc) OR uses a dual gain stage/follower stage topology which can be anything from a hybrid design like the X-Cans series or all tube would have either a Cathode follower (output taken from the cathode for near untity gain and low impedance output instead of voltage gain/hi-Z) or a White follower/Mu stage/SRPP (dual element with an upper load on the bottom amp,signal taken from the junction of).
Thge trick as always is to weigh what you would like to do against what is commercially feasable and again usually means comprimise if you want to hit a market price that will move large quanities of product."Ultimate Amps" are more for reviewers to drool over and make for pretty magazine ads but truth is no one is getting rich selling to such a small market and the old "don't give up the day job" rings true unless you are extremely lucky.
so we have affordable comprimised amps that work "pretty good" for most headphones the average budget consious consumer is likely to purchase that will perform mostly good but never truly great with the chosen cans unless you are one willing to "tweak" the amp later and FORCE IT to suit your needs.
Long winded way of saying 90% of all readily available amps are a comprimise as they must be to reach the widest audience but perform well within those limitations.If you want spectacular performance you need to choose YOUR personal reference headphones first then search out the amp that makes them sound the way YOU want them to with music.
I know,I know,shut up Rick !It was a simple damn question ! ;D
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Post by PinkFloyd on May 12, 2006 18:37:27 GMT
As Rick says above but "in general" Grado SR-1 are a piece of piss to drive (easy) and the Beyers have a reputation for not being so easy to drive (very similar to the AKG-K501) the DT-931 less so than the DT880 / DT990.
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Post by hower on May 13, 2006 2:29:24 GMT
Thanks for the detailed answer. It will take me a while to understand it.
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