TDA2005 build took a rout to fail. - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 7th September 2011, 05:36 PM   #1
cepa is offline cepa  Lithuania
diyAudio Member
 
Join Date: Dec 2010
Default TDA2005 build took a rout to fail.

Hey diyaudio pro builders, masters and wise ones, the worst amp builder in the whole world requires the assistance once again. So the thing is I got a scooter, and thought I would add some cool mods to it and the first thing that came to my mind is an audio system. So i scoured the internet and found a nice amp schematic (uses TDA2005), made it, and ofcourse it doesn't work. There isn't even any "power on plop", it makes absolutely no sound what so ever. My multimeter(which i think is broken) tells that there is no voltage going out of the amp (those connectors that connect to speaker). I've attached the schematic to the attachments part. I think that there are no cold joints. The only thing that i had to do is bend some chips legs to fit the holes and use a (i think it was R3) 2.4 kOhm resistor instead of 2 kOhm one, because my local electronics store doesn't have one. Here's some pictures of the amp.
[image]http://i56.tinypic.com/1roxtk.jpg[/image]
[image]http://i52.tinypic.com/t99rhs.jpg[/image]
[image]http://i55.tinypic.com/nclhtt.jpg[/image]
[image]http://i55.tinypic.com/2lxxwch.jpg[/image]
I hope these help.

PS. Please don't use any of the "Hard To Understand" electrical terms, and technical jargon.
Attached Files
File Type: pdf Bridged_amp.pdf (24.8 KB, 94 views)
  Reply With Quote
Old 7th September 2011, 06:34 PM   #2
diyAudio Member
 
firechief's Avatar
 
Join Date: Sep 2008
Location: Near Seattle Wa
OK - the fact that your meter dosent show anything on the output dosent mean that the thing is blown up, I am concerned that you say that the meter is maby broken. Lets start with the model and brand on the meter, and mabe a picture of it. You can find the problem fast with a meter, but perhaps not at all without it. We can also help with some simple tests to tell if the meter is broken.
__________________
"You can keep your insurance baby nothing is guaranteed" -Tom Petty
  Reply With Quote
Old 7th September 2011, 06:38 PM   #3
cepa is offline cepa  Lithuania
diyAudio Member
 
Join Date: Dec 2010
Quote:
Originally Posted by firechief View Post
OK - the fact that your meter dosent show anything on the output dosent mean that the thing is blown up, I am concerned that you say that the meter is maby broken. Lets start with the model and brand on the meter, and mabe a picture of it. You can find the problem fast with a meter, but perhaps not at all without it. We can also help with some simple tests to tell if the meter is broken.
It's a Mastech M-833, I'm pretty sure it's dead, i tried mesuring resistance and it showed random numbers. The probes are plugged in correctly and i wasn't touching the resistor leads or probes.
  Reply With Quote
Old 7th September 2011, 07:26 PM   #4
diyAudio Member
 
firechief's Avatar
 
Join Date: Sep 2008
Location: Near Seattle Wa
How about volts, just measure the power source, or a battery. Also, it has a battery in it, so you should check that next. If its internal battery is low it will cause ohms not to read correctly.
__________________
"You can keep your insurance baby nothing is guaranteed" -Tom Petty
  Reply With Quote
Old 7th September 2011, 08:20 PM   #5
cepa is offline cepa  Lithuania
diyAudio Member
 
Join Date: Dec 2010
You were right, battery was dead, it could barely power the built in speaker for testing continuity. Measuread the amp and it showed < 1 volt.
  Reply With Quote
Old 7th September 2011, 08:24 PM   #6
! is offline !  United States
diyAudio Member
 
Join Date: Jun 2005
Location: Midwest
You have shown us a schematic but what is the power supply to it, exactly (in circuitry details if possible)?

The schematic for your project is incomplete. What I mean is, it shows only an amp subcircuit which assumes (near enough) perfectly clean power up to that point in the circuit. It only has a power rail decoupling capacitor of 0.1uF (= 100nF). On the same PCB as the amp chip you should have far more than 0.1uF. The datasheet for TDA2005 suggests 100uF for "Figure 23 : Bridge Amplifier without Boostrap" (they need to proofread more!) which seems reasonable if your power supply itself has at least 1000uF capacitance in it (even more is better).

Your C4 polarity is reversed! Your PDF shows the wrong capacitor orientation on the component outline picture, look at the etching picture and the schematic, negative polarity should connect to ground and positive to pin #3 of the amp chip.

Also, you will get better performance if you increase the capacitance of C4 higher than 10uF (100uF or a little more) and also if you were using a lower ESR capacitor. If you want to stick with 10uF, try using a tantalum capacitor for C4 but MAKE SURE the polarity is right as they can pop quickly if polarity is reversed. Would a reversed C4 cause your specific problem? I do not know, but doubt that it would work properly with it reversed so I suggest correcting that polarity problem as the first step then retesting.

In this picture, http://i55.tinypic.com/nclhtt.jpg of the back of the amp chip, I see a couple little whiskers or hairs or something around the chip pins. If they are metal they could potentially short chip pins. Take a toothbrush and clean those out of the chip pin area. Otherwise (from what I can see of it in the picture), the pins look ok, I do not see a problem resulting from bending them. The picture of the bottom of the PCB also shows some kind of whisker-like fragment on the lower left side between one of the traces from a chip pin and the wide left-most trace (probably ground) which should be cleared off.

Otherwise, is this lead containing or lead free solder you used? Good leaded solder joints usually look shinier. It might just be an optical illusion from the picture but the solder joints on the lower row of chip pins look a bit granular and questionable. Ideally you would apply flux only to these joints and reheat them (no more solder is needed, just to rewet and flow the solder that is there)... but as mentioned above I would reverse polarity on the capacitor and retest before doing anything else.

As for your multimeter, maybe it just needs a fuse replaced?

Last edited by !; 7th September 2011 at 08:33 PM.
  Reply With Quote
Old 7th September 2011, 08:38 PM   #7
diyAudio Member
 
Join Date: Nov 2010
!!!!!Dude!!!!! Somehow you made a mirror image of the tracks on your board. It will not work unless you put the chip on the back.
  Reply With Quote
Old 7th September 2011, 08:48 PM   #8
! is offline !  United States
diyAudio Member
 
Join Date: Jun 2005
Location: Midwest
^ I agree the mirror image of the traces is confusing but it seems to have been pre-mirrored in the PDF picture so the amp chip does appear oriented correctly as soldered in on the PCB (as far as I can see looking at the camera picture).
  Reply With Quote
Old 7th September 2011, 08:56 PM   #9
cepa is offline cepa  Lithuania
diyAudio Member
 
Join Date: Dec 2010
For power I use a 12v battery, that's all. Also, those whisker-hair things are my cat's, she likes to mess around in on my table. I noticed that it was flipped while soldering it, but i just flipped the image and soldered according to the flipped version of the image. Also I have one 2200 uF capacitor laying around, can I use that instead of 1000uf capacitor?

I used solder with lead, and it's not that shiny, because it's been laying in my drawer for some weeks now, I think it's because of that.
  Reply With Quote
Old 7th September 2011, 09:08 PM   #10
diyAudio Member
 
Join Date: Nov 2010
Quote:
I agree the mirror image of the traces is confusing but it seems to have been pre-mirrored in the PDF picture so the amp chip does appear oriented correctly as soldered in on the PCB (as far as I can see looking at the camera picture).
**No the pins are backwards follow pin 1**
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
813 RCA amplifier - 25w, class A1, single ended,2 tubes,Rout~1ohm audiodesign Tubes / Valves 5 19th September 2010 07:34 PM
I want to build a uber-clarity 3(4?) way. First attempt=fail. What now? jackies Multi-Way 23 26th October 2009 01:52 PM
TDA2005 oscillation problms Petervg Chip Amps 14 18th September 2009 10:52 PM
TDA2005 Noise Roamin Chip Amps 7 22nd May 2009 04:10 PM
TDA2005 M or S? ocool_15 Chip Amps 8 2nd May 2005 07:49 PM


New To Site? Need Help?

All times are GMT. The time now is 09:02 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2