chu moy headphone amp! building one!

[shahedz]

after much googling etc and researching chu moy amps i have decided to build one from scratch!! wish me luck as i am as well as acquainted with electronics as the Armish!! But i thought this sounds fun so what the heck!
i have cheated a bit and manged to find a really helpful bloke who sells some parts and a premade PCB board so i just need to put the bits and solder. i emailed him and he has agreed to sell me the complete kit down to the tin and has been kind enough to get together a basic build kit for me! if anyone would like some pics let me know and i will get a thread togther but i will feel pretty stupid if the end product doesnt work!

[alexs2]

Originally Posted by shahedz

after much googling etc and researching chu moy amps i have decided to build one from scratch!! wish me luck as i am as well as acquainted with electronics as the Armish!! But i thought this sounds fun so what the heck!
i have cheated a bit and manged to find a really helpful bloke who sells some parts and a premade PCB board so i just need to put the bits and solder. i emailed him and he has agreed to sell me the complete kit down to the tin and has been kind enough to get together a basic build kit for me! if anyone would like some pics let me know and i will get a thread togther but i will feel pretty stupid if the end product doesnt work!

Excellent...hope it all goes well....if it's any consolation/help,I built my first pair of valve monoblocs last yr,and like you,had little or no soldering or electronic experience beforehand,but with a little help and practice,they work fine.
Most faults are down to occasional dry joints or missed ones,so check and check again before adding the batteries!

[shahedz]

cheers for your words of advice! hope my soldering skills are good enough, i think i may but a new tip for the iron my current one is as blunt as a twigg, and dont want solder all over the place, have you got a thread showing the mono blocs and the build stages?

[shahedz]

Cmoy Build Guide.

1, Add LED resistor & resistors R1-R2-R3 left & right. Values are on sheet with parts

2, solder IC2 (rail-splitter) bend middle leg back a little, put in hole following D shape on PCB, leave proud about 1/3 “ ( don’t force all the way down )

3, solder 8 pin dil socket in IC1 position. Note notch at end of socket matches notch on PCB.

4, solder C2 470uf radial caps note the + position, this is the long leg of the capacitor, opposite side to – gold band on capacitor. ( keep off cuts from legs )

5, use cut offs to jumper R4 positions.

6, solder C1L/R these can fit either way.

7, Solder pot/switch,

8, Solder LED red wire to + black wire to other hole.

9, Solder OUT jack socket to OL-OG-OR OL Yellow wire, OG Black wire, OR Red wire.

10, same for IN jack.

11, Install op-amp in socket, again notched end goes to OL-OG-OR end of board.

12 , Add holes to tin, 6mm for led & jacks 8mm for pot. You will have to notch lid a little so it closes.

13, Insulate bottom of Altoids tin, I use a laminated paper cut to shape.

14, bolt it all together & enjoy.

this is the build guide the gent who is selling the parts for me kindly conjured up. looks simple enough, lets hope i dont screw it up!

[eviljohn2]

Good luck, the CMoy amp is a very good but simple design so should make an excellent project. I'd recommend you practice your soldering a bit before going to work on the circuit board (make some cables for it or something) and a multimeter is at least as important a tool as the soldering iron.

Remember - continuity check twice, don't blow up once.

[shahedz]

Originally Posted by eviljohn2

Remember - continuity check twice, don't blow up once.

Hi evil!! excellent words of advice!

[shahedz]

finsihed the project today, made a bit of a dogs mess of the tin because of the lack of metal drill bits ( i knwo what they say a bad work amn always blames his tools.....but honest guv this is the thruth here!!)

at first instance the sound improvement with my sony £20 fontopia headphones is much ,muych noticeable. the sound is a lot more vibrant, and the bass is better already , i am really happy with it and was well worth the £18.44 i spent on it,

will try and post some pics over the weekend,

[eviljohn2]

Pics would be great.

As a newbie to electronics, what sort of problems did you have with the project and what would you try differently next time?

[alexs2]

Originally Posted by shahedz

cheers for your words of advice! hope my soldering skills are good enough, i think i may but a new tip for the iron my current one is as blunt as a twigg, and dont want solder all over the place, have you got a thread showing the mono blocs and the build stages?

One day I'll get round to doing a set of pics(perhaps after tidying the wiring first!),but there is a set of pics on the WAD forum gallery with a virtually identical one to mine.

[shahedz]

Originally Posted by eviljohn2

Pics would be great.

As a newbie to electronics, what sort of problems did you have with the project and what would you try differently next time?

to be honest i think my soldering still needs tonnes of improvement. i think i still use too much solder and its shows on the board, i was told you only need a tiny amount, but even when i try to melt a little a big blob comes off , if i can perfect this i think this would hlep no end, i followed your advice and checked everything out all the joints etc a few times before wiring it up and preventing any potential damage. it was a pretty simple project thanks to a premade PCB board that was clearly labeled where everything should go and went with out a hitch! i think one thing that i really should invest in, in a grip or clamp of some sort to hold the pcb in place when soldering things to it! would be real useful!

[StevieDvd]

My first cmoy was a bit of a mess, but worked!

I have only just recently soldered two small (smd) opamps onto small adaptor boards so they can plug in like the 8 pin opamps. Now that to me is small point soldering, the pleasure it gives when it actually works as well is great (well if you're a hobbyist at soldering that is).

I find the mint tins a little too delicate for long term usage and switched over to hammond enclosures.

If the mint tin you used was an Altoids they sell the mints in Tesco for 99p, and you get the mints as well!

But show some pics of your work as it does encourage others, honest.

Steve

[shahedz]

Hi Steve, i got an altoids tin but made a bit of a mess with it, but got a back up just waiting for some decent drill bits. how do i upload pics, mine are too big to upload!

[shahedz]

guys have posted a thread about a home made DAC

http://www.avforums.com/forums/showt...76#post2110676

would appreciate some of your feedback or advice to how difficult you think the project is! cheers

[shahedz]

Originally Posted by StevieDvd

My first cmoy was a bit of a mess, but worked!

I have only just recently soldered two small (smd) opamps onto small adaptor boards so they can plug in like the 8 pin opamps. Now that to me is small point soldering, the pleasure it gives when it actually works as well is great (well if you're a hobbyist at soldering that is).

I find the mint tins a little too delicate for long term usage and switched over to hammond enclosures.

If the mint tin you used was an Altoids they sell the mints in Tesco for 99p, and you get the mints as well!

But show some pics of your work as it does encourage others, honest.

Steve

gonna go your route and buy a plastic enclosue from maplins tomorrow! i think the tin is more grief than necessary!

[cwick]

If you're going to Maplins, consider picking up some Helping Hands. Makes fiddly soldering so much easier.