designing headphone amp

[mitsos]

Last headamp I built was ages ago, an Apheared47, sort of a suped up CMOY.. 2 dual opamps, a TLE-something virtual ground thingy, and a BUF634. It's got TONS of current. I used someone's perfboard layout and it worked nicely, with a 15VDC wallwart I stuck a regulator into. And it fits into an Altoids tin. 

I found a copy of one of the PDF's (there is another one which has the layout I used) but this is on forum member Kev's (he's still here isn't he?) site:

http://www.diyfactory.com/projects/headphoneamp/a47_assembly_and_schematic.pdf

 

[dagoose]

ok, both designs look nice! i like the second one with the opa222's because it's more simple to build on verboard. Thanks!

 

[mitsos]

hey I found the other layout. This is the one I used.  I also used the Alps pot sold by "tangent"at tangentsoft.com.. It's nice cuz it has a built-in SPST switch at the CCW position, so no need for a separate on-off switch.  I don't know what I ended up using for input caps, but I do remember thinking Wima FKP made a huge difference (vs some Wima polyester and some no-name crap caps).
have fun

 

[zayance]

Hi Guys, i've did myself a Headphone amp going with Wayne Kirkwoods Schematic.
I wanted to bother doing a double sided design, for trying to Home etch it, not a pro in PCB layouts but
So far so good, passing audio, will implement in the little mixer i'm trying to finish.

Just wanted to show the result as i'm pretty happy with the achievement.
I also did a Layout for if going Balanced, and i had a chat with Bruno2000 a couple of weeks ago because i wondered if he had purchased some boards from the ProAudio Design Forum, since i couldn't get them i made them, and he proposed some ideas on it,
RFI protections and Picofuses etc..., that i added to the Balanced Layout, they are not here, as i wanted to make simple for now....
I'm planning to build a Standalone unit for myself, that will have all Bruno2000 ideas, and maybe add some other features for me, will learn things on the way.

PCB dimensions are 100mm*50mm

EDIT: I'll avoid tinning the traces on top in the future, even for beefing them up, a friend of me that saw the PCB reffered me to a phenomenon that occurs when tinning traces, it's called "Tin Whiskers" interesting thing, here is an explanation:
EDIT: Actually didn't quit get it first when i read that, but it's tottaly fine and ok to tin traces on top, that will avoid "Tin Whiskers" actually, thanks to Mad.ax for correcting me on this by PM.
http://www.ami.ac.uk/courses/topics/0153_whsk/

 

[crazytooguy]

Here's my contribution:  It's based on the headphone amp from the Elliot Sound Products website. I really liked the design concept, and adapted it to accept a balanced input, as part of my monitor controller project, using a THAT 1200 balanced line receiver.

I haven't been able to breadboard it yet, so any comments would be appreciated.

 

[crazytooguy]

As it's sensitive to board layout, here's the board for it:

 

[ruffrecords]

Hi Guys, i've did myself a Headphone amp going with Wayne Kirkwoods Schematic.
I wanted to bother doing a double sided design, for trying to Home etch it, not a pro in PCB layouts but
So far so good, passing audio, will implement in the little mixer i'm trying to finish.

Do you really need a heatsink that big for a headphones amp??

Cheers

Ian

 

[zayance]

Hi Guys, i've did myself a Headphone amp going with Wayne Kirkwoods Schematic.
I wanted to bother doing a double sided design, for trying to Home etch it, not a pro in PCB layouts but
So far so good, passing audio, will implement in the little mixer i'm trying to finish.

Do you really need a heatsink that big for a headphones amp??

Cheers

Ian

I was told a Bigger Heatsink, gives a Bigger sound,  ;D hahaha....
No actually don't need it that big, i have a friend of me that gave me a couple of old Heatsinks that he had laying around from his job, i just cut it in half and used that...
Without it it was just not possible, but with even with half of that or just screwing it on the case will do of course, that's why they are all on one side....
But the BD139/140, are getting fairly hot in that design....