First cMoy NO SOUND hellllpp!!!

[breakfastchef]

Quote:

Originally Posted by Pars /img/forum/go_quote.gif You need to add solder to many of the connections, particularly those of the op-amp socket. Some of them look like they may not be making contact. Try to fill the entire hole and surround the pin or lead. Make sure you heat both the lead and the pad... you should be able to see the solder "flow" by itself if you are doing it correctly.

I agree. You have many incomplete solder joints. Some of the wire ends may not really be making contact with the copper of the board. Also, you can not rule out a bad op amp, though that would be rare.

 

[threepointone]

After you get those solder joints, check the pinout on your input/output jacks. They don't quite look right. If that's what you're referring to, the problem is that there's so many different kinds of jacks you could use with all sorts of different pinouts that he can't cover them all in the tutorial.

I can't really tell what's connected to what from your picture, but here's how they should be connected (assuming the jack you have is what I think you have):

Pin 1 goes to ground
pin 5 goes to left
pin 2 goes to right

The other two pins are switched--in other words, they disconnect from pins 5 and 2 when your headphones are plugged in. This is useful for certain applications where you can save power and turn off the headphone output when there's no headphone plugged in, but clearly you don't want to use those pins.

The tip of a TRS jack (i.e. your "1/8" or 3.5mm jack) is always left, ring is right, and sleeve is ground (going from tip of the jack to the bottom of the jack). Handy thing to remember when working with audio.
How to Wire Panel Components might have more interesting stuff.

The picture below is for the mouser/switchcraft model recommended by tangent. From what I've seen, most other jacks in this style have exactly the same configuration.

good luck on your first project; the troubleshooting will be worth it!

 

[GR/NDER]

thanks guys. i just added solder to everything and my jacks are wired just like you guys said. it still doesnt work. i wonder if my amp is burned out? a puff of smoke did rise up from something when it got real hot on my first test.... huh...

any way to test my amp?

 

[Joshatdot]

Where did this puff of smoke come from? the op-amp? if yes the amp is toast.

Also watch the Tangent vids

Tangent Tutorials

 

[Pars]

If you have a radioshack around, they usually carry a TL082 opamp which will work. At least you can verify the opamp that way for fairly cheap

 

[GR/NDER]

Okay! the amp was blown for sure.

I went and picked up a TL082 and put it in, held my finger on top of the amp to feel if it would get hot. I flipped the switch and sure enough, it got super hot in just a moment. I turned it back off and thats where i am now. Can you guys see anything in my pics that would explain this?

 

[GR/NDER]

OK! So my amp was definately blown.

I went and got a TL082 (Thanks Pars) and installed it. Put my finger over it and turned it on. Got hot super quick and shut it off.

Any ideas from my pics where I went wrong???

 

[jonjon0nline]

Check your R1 value. Nothing should be getting hot at all.

Also, if you haven't already, clean it with some 99% alcohol.

 

[GR/NDER]

What is my R1 value and how can I check it?

 

[Pars]

It looks like you have the battery wired backwards, at least from your pic of the amp in the case. In that pic, the + lead (red on the 9V connector) should be going in by the electrolytic on the left side... yours appears to be going in the negative side on the right.

Pull the opamp, and take your meter and measure the voltage at pin 4 (-) and pin 8 (+) of the opamp socket and verify that you are getting -4.5V or so on pin 4, and +4.5V on pin 8. That is about the only way the opamp will get that hot.

If that isn't it, did you ever check the stuff I told you to in post #9? If not, check that and post what your measurements are.

 

[GR/NDER]

Well I'll be damned. Cant figure this out. Who could I send mine to and have it checked out, and get an explanation as to what I did wrong? Is anyone providing that service?

 

[Rick]

umm...is everyone here blind? The ground plane is 2 strips of contacts that do not connect with eachother at any point....you need to jumper them together.......top and bottom of the protoboard

ie



O-O X X X O-O-O G-G O-O-O X X X O-O
O-O X X X O-O-O G G O-O-O X X X O-O
O-O X X X O-O-O G G O-O-O X X X O-O
O-O X X X O-O-O G G O-O-O X X X O-O
O-O X X X O-O-O G G O-O-O X X X O-O
O-O X X X O-O-O G G O-O-O X X X O-O
O-O X X X O-O-O G G O-O-O X X X O-O
O-O X X X O-O-O G G O-O-O X X X O-O
O-O X X X O-O-O G G O-O-O X X X O-O
O-O X X X O-O-O G G O-O-O X X X O-O
O-O X X X O-O-O G-G O-O-O X X X O-O

The G's are connected VERTICALLY top to bottom in 2 rows, but those 2 rows never connect horizontally, so connect them at top and bottom like so with a jumper, or if you're lazy, a large blob of solder.

 

[Pars]

If you look at the solder side pic, it appears that it is jumpered at least at the top. If the two rows were not connected together, it is unlikely that his voltage split would be the same, as the voltage divider resistors go to different columns. All the same, the OP should verify that these are jumpered together.

Looking at the pic again, the battery is definitely connected backwards. Measure the voltages at pins 4 and 8 again (to virtual ground) but this time tell us what the polarity is. I would be that pin 8 is -4.5V and pin 4 is +4.5V to virtual ground (backwards). This will make an opamp hot for a short period of time

 

[Juaquin]

You could have put the OPAMP in the wrong way. I did that once while testing several different OPAMPs; it was fairly dark and I didn't pay close enough attention. Several seconds after turning the amp on (but without headphones on, thankfully), there was a slight pop and a little magic smoke. Make sure you installed the socket the right way, then that you put the amp into the socket correctly.

 

[GR/NDER]

This is where Im at now after following everyones suggestions. Still doesnt work.