Cmoy noob part2;) [56kwarning]

[thegeek]

Yes, v+ and v- on the opamp socket. I just put one test lead on one of the socket voltage inputs and the other test lead on virtual ground, while my meter is on 20k ohm measuring. I do get 4.7, but this is without any power connected, just measuring the resistanse. And yes it does rise, but seems to semi-settle on 4.7 only very slowly rising from there. Keep in mind I have no theoretical knowledge/experience with electronics, I'm just learning as I go along

 

[thegeek]

Hmm, ok I rewired the battery and tried a opa2227pa, but so far no luck.
The opamp no longer gets (as) hot so I guess that is good

However I get no sound whatsoever, the voltage inputs seem good and I can't for the life of me find any solder bridges. I'm stomped

 

[PinkFloyd]

Quote:

Originally Posted by RnB180 I cant stop staring at the bloody finger.

I can't stop staring at the soldering.

 

[thegeek]

Humhum, hopefully my soldering skills will improve a little after a little more practice

Edit1: Does anyone know if running the wrong voltage(as in neg instead of pos) could have damaged any of the other components?
Edit2: On the two largest caps I had to bend the pins a lot to make it fit to my satisfaction, is it bad if the pins are in contact with the outer casing of the cap itself?

 

[Pars]

Quote:

Originally Posted by thegeek Humhum, hopefully my soldering skills will improve a little after a little more practice Edit1: Does anyone know if running the wrong voltage(as in neg instead of pos) could have damaged any of the other components? Edit2: On the two largest caps I had to bend the pins a lot to make it fit to my satisfaction, is it bad if the pins are in contact with the outer casing of the cap itself?

Unless the electrolytic caps are oozing, doubtful that you damaged them. No other component could have been damaged. It shouldn't make any difference on the electros as to the leads touching the case, as long as you don't wear thru the plastic coating (I would guess the can is tied to the negative, if at all).

I would get your ohmeter out and check continuity/resistance on everything against the schematic, from the battery leads in. In your first pics, you definitely had the polarity reversed, but the caps are in correctly (polarity-wise) per Tangent's layout. The 4.7K reading is bothersome, as it would seem to indicate that your caps aren't actually connected to anything (at least not where they should be). Your other readings per my link above were fine (opamp socket pins to ground)?

 

[arspy87]

I can't stop staring at the wires flailing everywhere

 

[nikongod]

i like the board.

perhaps it would be easier to troubleshoot over the web if it were laid-out "better" but for a first amp attempt, i give it my thumbs up.

im glad im not an arseh013 too. just wanted to share that.

as pars sugjested, go through teh circuit, with a mulitmeter, and poke around. do things make "sense?" i would check the electrolytic caps very carefully. they may have been dammaged by the reverse voltage. mine ususally jsut explode, but they may actually break down first from something else.

you may want to get a CHEAP rat-shack opamp chip for the circuit just to test. sound quality will be junk, but its cheap to test and blow stuff up if it comes to that.

also, when you tst the amp, do it 1 side at a time, and with a set of CHEAP 'phones laying on a table, nowhere near your ears.

 

[thegeek]

First of all, thanks for all the help and support.
I spent more time trying to find the problem, with nothing coming up.
So I decided to redo the entire circuit. This time I used the layout from tangents website, and just cut out pieces from my stripboard to simulate the board he used.
Now for the bad news.
Still no luck, exact same problem, I just can't get any sound.
I tried to find it, but I just spent (literally) most of the night making it so I need some sleep before I start poking around on it again

The power supply works, so I guess I did something in the amp section again

I've got some more images though

I know these caps suck, but I have lots of them and they are smaller, so you can see a bit better.

Hires1
Hires2

 

[looser101]

You missed the output jumper

. It goes from the outputs of the opamp to the centre of "M" jumper.

Good Luck,

-R-

 

[thegeek]

I'm speechless. You are actually right.
I missed the output jumper/R5. Reason is that I thought "I'll just skip R5 for now", and then never bothered to actually jumper it.
Thanks, it works great now