[Gomoo]

Can someone explain to me how an amp with a size of credit card is able to power a high-end headphone and sound as good as you all say? It's hard to understand.

 

[grandenigma1]

Quote:

Originally Posted by Gomoo Can someone explain to me how an amp with a size of credit card is able to power a high-end headphone and sound as good as you all say? It's hard to understand.

I agree

 

[cerbie]

Well, the Hornet is actually pretty big, now

(link).

But...why shouldn't something so small be able to handle it? It's not like they need cooling or anything like that.

 

[Gomoo]

This is not an answer to my question. If you think about bigger amps with bigger capacitors, how the hell can small capacitors drive big headphones with equal power and sound?????

 

[cerbie]

An amplifier basically takes an input signal (usually low power), and adjusts the power of the output to properly match it. Overall current is fairly small in headphones, and the power requirements aren't much, either. The ideal output of the amplifier is a high-power version of the input, the "straight wire with gain" ideal. Typically this is done by transistor-based ICs, where the input and output sides can pretty much be isolated from one another.

A capacitor in the way is mostly to handle bursts of pull, and to keep a stable voltage. After a certain amount of charge, anything bigger is pointless, unless there are large losses in the system (many separate components vs. few integrated components, FI), or some other design consideration requiring more.

Typically, you won't surpass 15mW by the time you're up to ear-splitting volumes. Being extremely insensitive to the load (which varies by frequency, and quite a bit) is much more important than actual power for headphones. As such, the trouble with fitting them into tiny parts is really cramming the necessary circuitry in there, and keeping noise down, and all the while, work on it by hand (small market = not enough $$$ for much automation), and still fit a battery that is easy to replace.

None of what it does has much to do with its size. The size of them, which is actually exceptionally large, is necessitated by having to use many discrete parts, rather than being able to stick it all inside of a small chip. If the demand were high enough, that could and would be done, and would add only a very small bit of size to current portable players.

Maybe growing up with an electrician and HAM for father has colored my view on such things, but I very much see it as, "finally, it's getting down to size," rather than, "how is something so small sounding so good?" Antennae take up space. Capacitors take up space. The rest really could be microscopic, or very near it, inside of a typical IC package, except that there is not a large enough demand for to warrant it. If the demand were high enough, a very good amp could just be a single IC with a capcitor behind it.

 

[fewtch]

Too bad there's not someone to make an opamp or opamps "designed by ear" to sound good with audio. I get the impression that the ones used these days like the AD8620 and OPA627 just happen to sound good by chance.

P.S. I agree... size really does not matter. However, this is not recognized at all in the "audiophile" community (and I mean *at all*). Put a design like the go-vibe into a huge decorative case, with a nice power supply bigger volume pot and possibly bigger PS caps, and it could go for $1000 as a "superior design for the audio minimalist."

P.S. yes, this is basically a criticism of the general "audiophile" community, for believing that big, glittering toys are always going to sound better than small, compact and well-designed units. Ditto for the concept that wall powered units somehow always sound better than something running on batteries.

 

[Dimitris]

I had the same question answered when i got my SR-71!

The hornet is even smaller so even better!

 

[bhd812]

I think it all comes down to the ear of the builder. Basicly he just tries this or that times 1000 and what ever he likes in the end is the finish sound. the build and the powering of the bigger cans are done cause of his standard ways of building amps...all amps power all cans (you know one exping can) and all amps have the tough case and same design look...inside and out (board make).

thats my Idea...I think