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jasonhanjk

Guide to fix up a Cmoy 2

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hi username, one of the OP2134 is for the right channel and the other for the left. The LM6171 is for the Virtual Ground. I think you should try to get the amp to work properly without the LM6171 first. Solder in the socket and use the extra wire from resistor legs to jumper as per the instructions for use without the LM6171.

 

Once the amp works ok, you can remove the jumper wire and plug in the LM6171. Actually the LM6171 is optional and increases power consumption so you may want to leave it out permanently.

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Thanks for the heads up.

 

Okay, so now I have the right channel in mono.

 

i am starting to wonder if it is better to start another one. no.gif

Edited by Username

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Check input jack connection, got fully insert?

 

Try pluck all opamp out leaving one and do listening test.

 

Or maybe you connect your input and output wrong again. laugh.gif

 

 

Alvin, why need resoldering on the sockets?

well...if opamps are not pin-compatible and i want to try out different types, i would need to resolder or rather redirect some of the pins right? sorry ah...a bit confused unsure.gif

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well...if opamps are not pin-compatible and i want to try out different types, i would need to resolder or rather redirect some of the pins right? sorry ah...a bit confused  unsure.gif

No, there are many opamps available which are pin compatible with the OPA2134, just need to make sure by checking their data sheets. I advise you read bpribadi's review of opamps. If he said the opamps are dual channels in one opamp chip, they will be compatible. But note that not any dual channel opamp can be used, just those that has been tried by the more experienced people. (I have heard that bipolar opamps are more likely to have problems.)

Edited by heady

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Woohoo... got mine to work.

 

I blew one of my OPA2134 and my LM6171 during my first bonehead episode.

 

The I realise that for my output, I connected the right to the ground, the ground to the left and left to the right. Yep, I am a bonehead.. whistling.gif

 

Thanks alot Jason and Heady.

 

And thanks to those who made the PCB and guide.

 

beer.gif

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well...if opamps are not pin-compatible and i want to try out different types, i would need to resolder or rather redirect some of the pins right? sorry ah...a bit confused  unsure.gif

No, there are many opamps available which are pin compatible with the OPA2134, just need to make sure by checking their data sheets. I advise you read bpribadi's review of opamps. If he said the opamps are dual channels in one opamp chip, they will be compatible. But note that not any dual channel opamp can be used, just those that has been tried by the more experienced people. (I have heard that bipolar opamps are more likely to have problems.)

ok thanks for the info. i will start with the opa2134 to get a feel of this first. adventures will come later laugh.gif

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Yep, I am a bonehead.. whistling.gif

Actually, we all make mistakes. I have had my share of burnt chips due to wrong connections. For a long time, I had trouble remembering if the red wire was + or - dry.gif For the record, power supply red wire is + (just in case I confused anyone).

 

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I got my fare share too, never solder a cap that is fully charge.

 

The solder is still in molten and I short circuit, "pop". That thing really fly, too bad that time I am half naked... no.gif

 

BTW, Username. Are you EE or electronic train? If not, I really need to change the guide to a real noob guide. biggrin.gif

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I am not EE trained...

 

I was giving the amp a a/b test just now, the low and high end was improved (thru my E2c) appreciatebly happy.gif , all just seemed livier now.

 

Now that I just ruined my altoid case... lol.gif

 

I need to figure it out again... yes.gif

 

 

Thanks ALOT guys!

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Now that I just ruined my altoid case... lol.gif

 

Oh no, Altoids are expensive. I just got some colleagues to get some from UK, one pound fifteen pence for each and hard to find. Somemore have to risk tooth decay to eat the candy. My friends all scared of the candy already. lol.gif

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Metro sells them at 4.50 ea...

 

But I just realise with the volume pot, it is impossible to fit in the altoids.. lol.gif

 

Looks like a case for me...

 

What do you all use to make holes in plastic casings?

 

EDIT: I don't mind if anyone wants to sell 2nd hand casings.... whistling.gif

Edited by Username

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Drill lol.

 

After you get a drill, you'll get a 2nd DIY amp too. yes.gif

 

Cheap way is to use soldering iron to burn through them.

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Metro sells them at 4.50 ea...

 

But I just realise with the volume pot, it is impossible to fit in the altoids.. lol.gif

 

Looks like a case for me...

 

What do you all use to make holes in plastic casings?

 

EDIT: I don't mind if anyone wants to sell 2nd hand casings.... whistling.gif

Hey, cool, I didn't know you can get Altoids at Metro, which branch?? Thanks. For fitting into Altoid tin, you cannot solder the pot to the board. You need to connect the pot via wires to the board, a little bit more work.

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Looks like a case for me...

username, the case stated in the project post seems to be out of stock in Farnell. There is available a bigger Vero case (S$7.50) in Koba Electronics @ Peoples Park Centre, with battery compartment door, which can be used, just a little too big to fit into pockets.

PICT00041.jpg

Edited by heady

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