Help me understand - gain and power

[ProRules]

Hey guys.
I'd love if someone could expain and enlighten me on what is gain and what is power.
And what would be needed for beyer's dt 990 - 600 ohms.
Someone told me that 19mw is enough for dt 990 600 ohms, and from there the gain is important mostly.

Thanks!

 

[MindsMirror]

It can be helpful to think of a physical analogy, since electronics can be somewhat abstract depending on your background in the subject. The best one I can think of at the moment is a car analogy, where the gain is like the gear ratio, the voltage is the torque, and power is still power. If you're trying to tow a heavy trailer at low speeds, you will need a low gear with a high ratio to provide enough torque. If you're having a drag race, you will need to use higher gears to go faster. Both situations might still use similar power, but you're using different gears for the different types of work you're doing. The 600 Ohm DT990 doesn't need more power than a typical 32 Ohm headphone, it just needs higher gain and voltage, like the car needs a higher gear ratio to tow the trailer vs doing a drag race.

 

[ProRules]

It can be helpful to think of a physical analogy, since electronics can be somewhat abstract depending on your background in the subject. The best one I can think of at the moment is a car analogy, where the gain is like the gear ratio, the voltage is the torque, and power is still power. If you're trying to tow a heavy trailer at low speeds, you will need a low gear with a high ratio to provide enough torque. If you're having a drag race, you will need to use higher gears to go faster. Both situations might still use similar power, but you're using different gears for the different types of work you're doing. The 600 Ohm DT990 doesn't need more power than a typical 32 Ohm headphone, it just needs higher gain and voltage, like the car needs a higher gear ratio to tow the trailer vs doing a drag race.

Okay that clears up a bit.
How much gain and voltage on average is needed for such cans to get to lets say, 90 decibels?

 

[MindsMirror]

0.39V and 0.25mW would be 90dB, but you need some headroom since the peaks in audio go higher than the perceived or average loudness. It depends what you listen to, but I'd say a safe amount of headroom is 20dB, which would mean 110dB, 3.9V, and 25mW. You normally just need to know the power. If the amp's specs say it can do 25mW at 600 ohms, that automatically means it should have enough voltage and gain also.

 

[imblub]

Keep in mind that there will be more distortion when you approach the maximum power of the amp, making the headroom slightly more important.

 

[ProRules]

0.39V and 0.25mW would be 90dB, but you need some headroom since the peaks in audio go higher than the perceived or average loudness. It depends what you listen to, but I'd say a safe amount of headroom is 20dB, which would mean 110dB, 3.9V, and 25mW. You normally just need to know the power. If the amp's specs say it can do 25mW at 600 ohms, that automatically means it should have enough voltage and gain also.

Then why would people recommand like 140mW amps on 600 ohms?
Hell even the magni 3 which is 230mW.

 

[MindsMirror]

Not all 600 ohm headphones are the same. Some will have lower efficiency than the DT990 which means they need more power. You may also need even more headroom if you listen to very dynamic movies for instance.

 

[ProRules]

Not all 600 ohm headphones are the same. Some will have lower efficiency than the DT990 which means they need more power. You may also need even more headroom if you listen to very dynamic movies for instance.

So what would be the sweet spot? Is 143mW Topping A30 enough overkill?
Or i should head for Magni 3 like everyone says?
Because the Magni would be 170$ compared to 110$ of the A30 duo to shipping.

 

[MindsMirror]

Sounds like the A30 is a better deal for you. The difference between 143 vs 230 mW is barely even noticeable.

 

[ProRules]

Sounds like the A30 is a better deal for you. The difference between 143 vs 230 mW is barely even noticeable.

Okay, thanks