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Beginner trying to do a CMoy

post #1 of 14
Thread Starter 
Well I must admit I feel very stupid not being able to do this, I am having issues from the get-go. If anyone has some patience to help me out with these very basic questions I would greatly appreciate it. I have all the parts and basic tools. I am hoping that once I understand this and build a few I can move on to other builds. This is more for the enjoyment of doing it and learning how to make this stuff than the actual finished product of the CMoy, I am hoping to make this a stepping stone to something bigger.


1) What is meant by "installing" a jumper. Right now I just have them sticking through the holes on the protoboard with the extra bits bent out so they wont fall out. Where do I solder the sides to?

2) Looking at the layout (see here) I don't understand where I am soldering the parts to.

If I can get an understanding of these basic issues, I am fairly confident that I can stumble my way through the rest. Feel free to post links, I spent the past 30 minutes searching through the forums and it seems everyone grasped this much easier than I ;p

If anyone would like to contact me via AIM (would be greatly appreciated), my screen name is a11dian.

Thanks in advance for your patience
post #2 of 14
Quote:
Originally Posted by malldian View Post
Well I must admit I feel very stupid not being able to do this, I am having issues from the get-go. If anyone has some patience to help me out with these very basic questions I would greatly appreciate it. I have all the parts and basic tools. I am hoping that once I understand this and build a few I can move on to other builds. This is more for the enjoyment of doing it and learning how to make this stuff than the actual finished product of the CMoy, I am hoping to make this a stepping stone to something bigger.


1) What is meant by "installing" a jumper. Right now I just have them sticking through the holes on the protoboard with the extra bits bent out so they wont fall out. Where do I solder the sides to?

2) Looking at the layout (see here) I don't understand where I am soldering the parts to.

If I can get an understanding of these basic issues, I am fairly confident that I can stumble my way through the rest. Feel free to post links, I spent the past 30 minutes searching through the forums and it seems everyone grasped this much easier than I ;p

If anyone would like to contact me via AIM (would be greatly appreciated), my screen name is a11dian.

Thanks in advance for your patience
This is a bit of a chicken and egg problem. It's not a lot to learn. You'll get it quickly. It's just hard to know what you get and what you need help with. AIM or in-person is a good idea.

From http://tangentsoft.net/audio/cmoy-tutorial/assy.html
Section "Stage 2: Adding the Amplification (Signal) Section" has two pictures that show where to put parts on the ink side, and how to solder them on the copper side. Installing just means putting it through the whole from the ink side, and soldering it to the copper side.

A point to point build would probably be easier to understand than this protoboard, since you could see the connections go directly from one part to another. With this kind of protoboard, you might have to follow (trace) through several strips of copper and jumpers to follow a connection between two or more parts. If anything is confusing, try comparing the layout on the protoboard with the schematic. To get from the protoboard to the schematic: the copper traces, jumpers, wires, and component leads all conduct electricity, so you just (mentally) connect all those until you get to the actual parts. Then draw a line between the parts. From the schematic, a line can be the component lead, a wire, a jumper, or a copper strip (trace) or some combination. You'll also hare places (nodes) where two or more parts get connected. Those can be a bit tricky to find on protoboard because the traces can get a little convoluted.
post #3 of 14
If I had a camera this would be easy, but alas,

1) instead of having them bent out, bend them into each other so they overlap.

Solder the parts of the jumper that overlap.

That way you've made a bridge between two holes.

Does that help?

2)

For example, lets look at C1 on the left side of the board.

Define the point where batt + goes into the board as (0,0).

Do you see the "+" at point (1, -1) for C1 and the "x" at point (1, -2)? That means that the positive lead should go through point (1, -2). The positive leads for caps are the longer leads.

The "-" sign is on the other side and the point that lead should go through is (1, -3). Negative lead is shorter lead on the cap.

3) Look at R1 on the left side.

One of the leads will go through at (2, -1) and the other lead will go through (3, -2)
post #4 of 14
First of all, using protoboard also known as breadboard means you are not actually 'making' amp.
Protoboard is used to provide prototype of the final project.
Means it's just testing and checking circuit on it before you finalize it.

Add jumpers means, wiring on the protoboard.
Protoboard has connection inside (see the picture there are separete groups of white row & column) but you need to connect it like connect the component with wires.
Jumper is actually wires used on the protoboard with metalic end so you can press it down on the protoboard.

On the protoboard you are not going to solder any parts like I said before.
Protoboard is only used to test, check and provide function before you make it on the Circuit board.

You should get the circuit board, single or double sided, and put every parts on it and then solder every parts while you wiring them manually.
If you have PCB, printed circuit board, with circuit drawn on it, you just need to put all the parts and solder it since wiring is already done on the board.
post #5 of 14
Quote:
Originally Posted by mcramen View Post
First of all, using protoboard also known as breadboard means you are not actually 'making' amp.
Protoboard is used to provide prototype of the final project.
Means it's just testing and checking circuit on it before you finalize it.

Add jumpers means, wiring on the protoboard.
Protoboard has connection inside (see the picture there are separete groups of white row & column) but you need to connect it like connect the component with wires.
Jumper is actually wires used on the protoboard with metalic end so you can press it down on the protoboard.

On the protoboard you are not going to solder any parts like I said before.
Protoboard is only used to test, check and provide function before you make it on the Circuit board.

You should get the circuit board, single or double sided, and put every parts on it and then solder every parts while you wiring them manually.
If you have PCB, printed circuit board, with circuit drawn on it, you just need to put all the parts and solder it since wiring is already done on the board.
It's confusing enough without getting into how a protoboard can mean two things. The picture shows a solder-type protoboard, not a solderless breadboard. I hope that's what malldian is using. If not, well, that explains the question.
post #6 of 14
Quote:
Originally Posted by SiBurning View Post
It's confusing enough without getting into how a protoboard can mean two things. The picture shows a solder-type protoboard, not a solderless breadboard. I hope that's what malldian is using. If not, well, that explains the question.
oh ye, now I see 'halve the protoboard' in the picture I missed it.
halve the breadboard is very hard almost impossible, thanks to point it out.
post #7 of 14
Study the schematic closely to comprehend what side of what component connects to another, or ground, or V+, V-, jacks...

Print out the layout of the pins of your op/amp and realize you count from the dot or notch counterclockwise from 1 to 8 when looking at the op/amp from its top surface.

This will save you a lot of confusion: The schematics are not literal layouts of components like an architectural plan, but rather show what connects to what and are laid out primarily for clarity of identification of symbols, values...The same schematic can be drawn several ways.

Place ALL your components on the board and shift them around to see what fits where, etc. You can get more sophisticated in layout later.

Most common problems: solder bridges or bad solder joints--wrong part or part reversed (esp. diodes), failure to make a ground connection somewhere.

CMoy is a fine amp. After you have it operating consider the high impedance modified Linkowitz crossover using Tangent's printed circuit board. The wiring is tedious, but it is worthwhile (I think). If you do this use different colored wire for the various groups of wire and write down what color represents what part of the wiring...and be sure everything is well grounded. Mine was quirky until I connected all the grounding points together.

F
post #8 of 14
Thread Starter 
So I can do this "point to point" without the board? That would make it eaiser just a bit messy I think.
post #9 of 14
Yes, but it is hard to do considering you have to make 8 connections to your op amp socket. Do an internet search for dead bug, point to point, and manhattan construction techniques if you like.

Most people like to use a perf board because it provides a matrix upon which to place parts. As long as parts are connected properly you can wire the components as you wish.

F
post #10 of 14
Quote:
Originally Posted by malldian View Post
So I can do this "point to point" without the board? That would make it eaiser just a bit messy I think.
Go to your local ratshack (Radio Shack) and pick up a PCB (Part Number: 276-0150) If you live outside of the CONUS then I cant help you pick a board. Is it possible to do it , Yes!; however, it is not practical and there could be some solder bridges and more time trying to find loose connections and the such.
post #11 of 14
Thread Starter 
Well I just screwed up haha, I need to buy a desoldering pump. I'll get it sooner or later
post #12 of 14
Quote:
Originally Posted by malldian View Post
So I can do this "point to point" without the board? That would make it eaiser just a bit messy I think.
For now, stick with what's in the instructions. You'll learn enough doing a couple projects to move onto some other method, and you won't have to worry about a lot of other things best left for later.

Point-to-point is by far the easiest way to make it like the diagram (MIL-TD) or schematic. The main advantage is you can see all the parts and all the wiring and can even lay it out (mostly) to look like the schematic. It's got a few other advantages, but a lot of down side. Most important for you, at this stage, is you'd need to think about how to mount and connect every single part, and then buy all those extra parts. One of the main downsides to any kind of circuit board (printed or proto-) is that you can't see the wiring and components at the same time because the wire is on the back of the board. It's not a serious problem with this kind of proto-board if you put all the wiring and jumpers on the component side, and only have solder points on the back. The front has an ink print of the copper traces, so you can still follow the whole circuit. That's why it's a good system for this project.

Point to point is also really cool if you're trying to make your amp into a beautiful work of art. Works especially nice with tube amps.

A good compromise that I like a lot is to use perfboard (like protoboard but without any copper traces) and use a lot of push-in pins for solder nodes. With this system, it's easy to use IC sockets, and still get most of the wiring on the same side as the components. But it's as much a pain to do as point-to-point.
post #13 of 14
Here is a picture of a CMoy I built on a breadboard. Its blurry but my interests (and money) go into stereos and not camera equipment! LOL

post #14 of 14
Thread Starter 
Ok, thanks for all the help, I am buying the PC Board for another try.

I messed up on this one because while soldering two jumpers that were close to each other, they kind of melted into each other. How do I avoid that?


You guys are great, thansk for all the help!
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