my 1st DIY headamp, DONE!

[aaa 0]

the design is basically a Pimeta clone, a pimeta in a MINT!

it is not fully completed yet since the volume control pot is by-passed, the CRD for biasing op-amp into class-A is not installed, and most importently the thing is not put in a mint casing yet.

total RETAIL cost for all the parts exc tools/batterys is very close to S$100.

 

 

 

the surprising thing is that it runs on the first try! (although I have tested and corrected multiple error b4 acutally running it, including a spoiled OS-con).

 

This amp is actually my warm up for the coming PPA clone.

I was thinking of trying something easier first b4 actually solder the PPA, my PPA layout is already standing by...

As I progress I believe this amp can actually be more difficult to solder due to the density and the number of cross junctions.

 

updates:

 

Just received the CRD from Bram. Installed, still evaluating. Thanks Bram!

 

1st evaluation of audio quality.

with AD8620 and AD8610, gain set to 1 (jumper wire), line-out from creative nomad jukebox3, single 9v zinc-carbon battery, senn HD-650

compared to the headphone out of jukebox3 (which has output cap modded), the bass is much stronger and deeper.

Speed seems to be faster.

many minute details which are never heard of b4 can now be noticed.

overall the differents compared to headphone out is very noticable

will add more comment reg later

Edited December 26, 2004 by aaa

[heady 0]

Good job, aaa. Wow so small. I thought my Pimeta clone looked small but your's is much smaller. Are you a surgeon? Your amp is resting on medical gauze.

 

May I ask where you get your caps (blue, red and the electrolytics) from?

 

Well done.

 

[aaa 0]

all caps are from koba.

the blue one is 2.2uF 50v polyester

the purple electrolytic is 20v 180uF OS-CON SP series.

the rest you should be able to read from the picture.

 

now waiting for Bram to sent me the CRDs.

Still cannot decide whether to buy the alps RK9 pot from farnell.

it cost like $10!!!

[tropicalrips 0]

very cool

i think u'll beat me to the goal of "PPA in a tin" project

also...are u a surgeon we should restart the contest that was placed here a while back before the server crash and the forum was lost for a month...

 

smallest Cmoy u can built it'll be fun, one rule...cannot be ectched PCB using surface mount components

[huangyong 0]

Wow, looks nice and compact. is this your first time doing p2p soldering? it looks really good for a newbie's work. mine really sucks when i first started DIY.

[bpribadi 0]

Well done aaa!!! Really deserve AAA rewards

 

Very compact and tight spacing

 

Knowing your attention to detail, you must have planed the layout very well

 

Looking futher for the amp in the casing

[digi01 0]

congratulations!

I agree with bram,your layout is skillful

[av98m 0]

Given the amount of purple(lotsa os-cons) I see in this amp you could call it the "Barney" amp

[aaa 0]

Thanks for all your compliments.

Am I a surgeon?

I'm just a slack ORDing NSF, with all the free time.

 

There's some thing I need the help of you all,

How can I drill a good hole on the tin without buying a power hand drill?

 

When I get my pot from Heady, I will start to finish the final details.

at the mean time I will start to kick off my PPA clone, which will about 15X the volume and 25X the weight of this Pimeta clone.

The experience I had from the PIMETA Clone will definitely help.

 

[heady 0]

aaa, what I did to get pain free and nice big hole on the tin, is to go to Popular and buy ($1.30) the hole puncher thingy which looks like a plier (Genmes One Hole Punch). Then I cover the tin with masking tape to prevent scratches. Mark the point where the hole should be centred and do it with the hole puncher.

 

The first time you do it, you will swear it won't work, until suddently the puncher goes thru the metal and you will be rewarded with a nice perfectly round hole of 6mm. This is just right for the headphone jacks and most switches.

 

For the pot, you need about a 9mm hole, so this is a bit tricky. You make a point as usual and then use a compass to draw a 9mm circle. Using the puncher, you carefully punch a series of holes within the drawn circle and it's done!

 

Nice holes without the aggro. Don't use drills, repeat don't use drills. I have used a power drill and a dremel like drill (actually a dentist laboratory drill) and with them, I have destroyed a few tins. The metal is too thin to drill holes bigger than 5mm without tearing and distorting the tin. Eating the sweets to get new tins weren't so fun either.

 

(BTW - the pot has been packed and sealed and awaiting delivery to post office tomorrow)

 

[aaa 0]

Heady you are my life saver!!!

which popular branch did you see it?

$1.3 is cheap for any type of puncher.

In fact I have tried using my normal puncher, it does work very well, but with the shape of tin it's just impossible to reach the place I want to punch.

a puncher of plier shape, it's easy to imagine how it works.

[heady 0]

aaa, I stay in Tampines so the Popular branch I frequent is in Simei. You may want to know this is not my idea, I saw this tip in the US forums posted by one of the more experienced DIYers. I am glad to help any one avoid my pain in trying to case the amps. I used to spend more time casing the amp then building it, until I used the puncher.

 

[aaa 0]

finally finished the amp

[aaa 0]

case opened.

[aaa 0]

One polar connector for battery/adaptor

Another non-polar connector for on/off switch.

I like the flexibility.

Edited December 26, 2004 by aaa