[balou]

Why do you want 34V? Eager to make some home-fried headphones? *g*

Quote:

Also, is the 12v power supply in a computer good enough for audio

Um... a 12v power supply is limited to... 12V. You won't even be able to bring your opamp anywhere near 34v.

And yes, computer power supplies are rather noisy

 

[Ikrit42]

My recommendation, as a fellow newbie in the world of EE:
Get this book, and read it. It will teach you most of what you would need to know to build/design yourself an amp.
I'm just getting to the point where I'd like to start designing my own circuits, and I've done a couple custom layout cmoys and stuff to learn board design from.

 

[spiftacu1ar]

Quote:

Originally Posted by balou /img/forum/go_quote.gif Why do you want 34V? Eager to make some home-fried headphones? *g*

read the above posts, which say that 44v is barely enough...

 

[j4cbo]

A +/- 15 volt supply is more than enough, even for high-impedance headphones.

 

[Gunsou]

Quote:

Originally Posted by j4cbo /img/forum/go_quote.gif A +/- 15 volt supply is more than enough, even for high-impedance headphones.

Not necesarily. It really depends on ur average listening level.

 

[jcx]

Quote:

Originally Posted by spiftacu1ar /img/forum/go_quote.gif read the above posts, which say that 44v is barely enough...

Quote:

Originally Posted by j4cbo /img/forum/go_quote.gif A +/- 15 volt supply is more than enough, even for high-impedance headphones.

Quote:

Originally Posted by Gunsou /img/forum/go_quote.gif Not necesarily. It really depends on ur average listening level.

You need to look at headphone sensitivity, impedance

"Voltage Hungry" Senn are 300 Ohms, 98 dB/mW, these require more V than Grados or K701 (other examples of "hard to drive" headphones - but they need way more current than HD6xx but less V)

Senn HD6xx: 300 mW is +25 dB re 1 mW so the peak SPL at 300 mW into these headphones is:
98 + 25 = 123 dB which requires +/-13.4 V into 300 Ohms

123 dB peak SPL is adequate for clipping free reproducition at live levels for most acoustic music
http://headwize.com/articles/hearing_art.htm
the rare high dynamic range music recording with 20+ dB peak-ave would allow over 100 dB average level - which shouldn't be used for even a couple of hrs per day

and any recording with over 10 dB peak to ave ratio today is cause for comment with the "loudness war" squashing recorded dynamic range on any "popular" genre, backing down from 120 dB clipping level 10 dB peak-to-ave gives 110 dB ave SPL - with a OSHA 30 min exposure limit!

so +/- 15 V supply headphone amps that can swing to >+/- 12-13 V (24-36 Vpp) are fine for most common headphones, some AKG with low sensitivity and the 600 Ohm Beyers may need more to reach live peak SPL, but this is a special niche application
balanced operation allows twice the Vpp output with the same supply and would satisify the Vswing needs of most of these difficult headphones with +/-15 V supply

I think lots of headroom is a good idea but not enough to insist on +130 dB SPL clipping levels from a beginners 1st few homebuilt projects

 

[Gunsou]

with +/-15v supply assuming a +/- 12V swing u will only deliver about 240mW in 300 ohms phones. And that would be the clip limit. In terms of power that may not be enough but as i said and as jcx said it depends on listening level and thus sensitivity of the phones.