[TURBO]

Hi, I do have a simple problem. I am building a Cmoy and I connected all the components but 2pins of the opamp are loose. I dont know where these two pins connects to. I am talking about pin 1 and pin 7 of the opa2132PA. Could someone shows me where the 4 pins of the opa132pa connects to. Just to make shure that everything is ok. I dont get any warming of components but not sound. Thanks in advance.

 

[meat01]

Maybe this will help you.

 

[puppyslugg]

Pins 1 & 7 are Left and Right channel outputs. My guess would be, if they aren't connected to the output jack(s), you wouldn't get any sound. What pins# do you have connected to the output jack(s), now?

 

[TURBO]

I have:

Pin8 --> v+
Pin7 --> empty
Pin6 --> r3 --> r4 --> r. out
Pin5 --> r2 --> ground, r2 -->c1 --> r. in

Pin1 --> empty
Pin2 --> r3 --> r4 --> L. out
Pin3 --> r2 --> ground, r2 --> c1 --> L. in
Pin4 --> v-

Please let me know what is wrong. Thanks.

 

[PeterR]

What puppyslug said, those are the outputs, connecting them to the output jacks would help.

Edit:
When looking at that schematic, maybe I see what could have confused you - it says R5 is optional, but if you don't use a resistor there you don't just leave its place empty but you connect the opamp output directly to R4 and the output jack...

 

[TURBO]

Quote:

Originally posted by PeterR What puppyslug said, those are the outputs, connecting them to the output jacks would help. Edit: When looking at that schematic, maybe I see what could have confused you - it says R5 is optional, but if you don't use a resistor there you don't just leave its place empty but you connect the opamp output directly to R4 and the output jack...

Exactly what I need. Thanks a million.

 

[TURBO]

Update. No luck. I put everything and no sound. The only component that I dont put is R1 in the input. Neither volume pot. But should work without this, right?. Thanks.

 

[TURBO]

SUCCESS!!!. I managed to create a Cmoy Amp, after destroying one. I wired everything from a old Cat5 network cable. So now I have a multicolor Cmoy. It looks like a Carnival Cmoy. Let me tell you something. Is a lot better to do it yourself. One week ago, I ordered a cmoy from somebody and it sounds horrible. A total mess. I did thow it in the garbage can. Then, I decided to build it myself. I created a very good sounding Cmoy amp. WAO. I am scared of the sound of my DR7 minidisc. I stopped hearing music. I am afraid of the amp I created. But still, I do have some problems:

1} The wires are too long so I wont be able to put it in a mint case. Please, give me some ideas.

2} I would like to know how to make holes to metal (mint case)?. I do have a drill.

3} How the ..... do you guys cut the radio shack board (150). Every time I try to cut it, it brakes in twousand pieces.

Thanks in advance

 

[KTpG]

You have to score the bored where you want to break it... score it VERY well. I worked on mine for 15 minutes or so to get the cut perfect. Score one side REALLY deep, then run over the other side a few times (enough to leave a ridge) and it breaks right in half. Then you can file it down to make it look better. Don't breathe the dust, though... or at least, don't breathe very much of it.

 

[jamont]

It's really easy with a Dremel and a cut-off wheel.

 

[puppyslugg]

Try scoring it on both sides.

 

[Arzela]

A good pair of scissors (sp) makes
the task very easy for the ratshack
boards.

 

[tangent]

Quote:

The wires are too long

Put the board in the case with the components still attached to the wires, but with all the wires going up and out of the case. Put a 9V battery or two in there with the board. Now, figure out where you have room to put the panel components. Plan where to drill the holes, and use a scribe or awl or some other sharp instrument to poke dents into the tin to mark the center of your planned holes. Now take everything out of the case and proceed to step 2:

Quote:

how to make holes to metal (mint case)?. I do have a drill.

If you want to use twist drills, you will get the best holes by starting with an 1/8" or so drill and then moving up a little at a time by 1/16ths at most (1/32nds is better, 1/64ths still beter) until you get to the hole size you want. A hole gauge is a smart purchase before you start work. Drill slowly, and use very little pressure on the work face. Let it cut the tin away very slowly, especially for the first few holes. With the larger holes, you don't have much choice in this: it will tear quickly through the tin no matter what you do.

A quicker alternative to this is a step bit. These are expensive ($30 or so) but you only need one and it automates the same process that I outlined above. You might need to stop one hole size short of where you want to end up and then make one final cut with a twist drill.

Quote:

How the ..... do you guys cut the radio shack board

Scoring does work if you take the time to be careful, a Dremel with a cutoff wheel and then a sanding wheel to round everything back out is better. An alternative you may consider is a nibbler, which will result in less dust but more wastage.

 

[MisterX]

A elcheapo hand held paper punch works great making for the IO jack/Switch holes.

 

[TURBO]

Thanks, guys. Thanks, Tangent. Today, I am going to Home Depot. I will post the final result when I finish. This project takes time and my wife is arround. She wants me to cut the grass and I prefer to finish my project. Let's see how I manage this situation.