CMOY! Help a Newb, Feel Good About Yourself

[Wyloch]

This will probably seems trivial to seasoned veterans, but if you could help you'd save a guy a TON of frustration.

...complete newbie...

I'm following Tangent's famous guide on how to build a CMOY amp. I've read through it thoroghly, as well as Chu Moy's guide at HeadWize. I've finished building the power section, and now I'm stuck at the amplifer/signal section.

Tangent's guide is obviously aimed at non-noobs, because the section devoted to putting together the actual amplifier part is very vaguely written. In this section, according to the pictures, you must add six resistors and two capacitors. However, the guide doesn't specify which capacitors, or where to put them! What holes? Which resistors?

Furthermore, how do I incorporate the power switch, volume knob, and input/output jacks? I got two RadioShack headphone (1/8) jacks, and these jacks have five connectors on them! The diagram on the back of the package is obscure, unlabeled, and basically useless. Anyone know how to hook it up?

As far as the volume knob, I've got a potetiometer, and on the back of it are just two terminals, unlabeled. How am I supposed to know which is in and which is out? Moreover, is the potentiometer the very first thing that input wires from the jack go to? If so, how am I supposed to do it with only two terminals?

For reference, I am using the 0170 chipboard, not the 0150.

[digi01]

Originally posted by Wyloch
I got two RadioShack headphone (1/8) jacks, and these jacks have five connectors on them! The diagram on the back of the package is obscure, unlabeled, and basically useless. Anyone know how to hook it up?

I draw a simple illustration,wish it is helpful


ZANG

[digi01]

Originally posted by Wyloch
Moreover, is the potentiometer the very first thing that input wires from the jack go to? If so, how am I supposed to do it with only two terminals?

yes,the pot before the jack.i guess you got the wrong pot.the pot should be a six terminals dual tirm.see attached pic.

BTW,here is a drawing,for connect all parts:
http://headwize.com/ubb/showpage.php...7&srch=digi01;

good luck
Z

[Wyloch]

WOW! HUGE help - especially the second diagram. Tomorrow I hope to get cracking on it. I'll post how things go and if anything goes awry, hopefully you'll continue the benevolence you've shown.

...Seriously - this is a HUGE relief. I've been ****ed off all day at this project.

[Wyloch]

Well, I built that schematic and all it did was cause the op-amp to start smoking. Thanks for trying though.

[moe29]

Wyloch,

Don't give up! I built this little amp and it does work...

could you show us some pics? Maybe if we see what you're doing
we could supply some help.

You mention you're using a different "chip board"... are you sure
it has the same circuit pattern on the bottom?

[moe29]

Did you see these illustrations?

Pic 1

Pic 2

Pic 3

[Wyloch]

Yep, but as you can see none of the resistors are labeled and the jpg is too low quality to make out the color bands, so there's no way to know which ones go where. I tried comparing those three pictures to the diagrams at HeadWize, but they simply don't match.

[moe29]

I see, he doesn't have a layout diagram posted yet for the board
you are using (the 276-0170).

Do your self a favor and run back up to Radio Shack and get the
board with part number 276-0150.

Then you can use the layout diagram that is posted, this will help
you out a lot.

If you want to keep trying i've attached this photo which might
help you out a little. I would show you how to attach the
0.1uF capacitor, but i can't see the underside of the board. See
how it's done in the other layout and do likewise. I know that
one lead has to attach to R2 and the other lead becomes the
signal IN spot.

oh yeah, resistor values are found in the parts list, that's how
you know what the value of R1, etc. is.

Good luck and let us know how it's going!

[Wyloch]

Alrighty! So I've now got a working power section, an LED in the circuit that I finally DIDN'T blow up, and all of the resistors are in place. I ended up sticking with the 0170 board, as I've already put too much money in to this project. But what I've done looks quite nice, with flawless soldering.

NOW...

Once I get these last two caps in, I'll be able to test for audio using alligator clips and all that. Then, I'll have to figure out the in/out jacks, volume control, and power switch, but that's all for another day.

As you said Moe, it's hard to tell where the two 1uF caps are supposed to go, and I've tried to figure it out. I can't. Got any ideas?

Also, the V- and V+ hookup wires used to test the power section have to be hooked up to pins 4 and 8. That would be the lower left and upper right branches of the IC socket, right? I've oriented so that the notch is facing away from the power caps.