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PostPosted: 27 Mar 2014, 00:48 
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Joined: 28 Dec 2010, 22:07
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I have been working on one of these for the past couple of days. I've been using Manhattan Construction and therefore have been able to place the amp on a small board about 2in x 4.5in. I powered it up tonight and ended up blowing up both chips, both TDA2030A. Although I've got more on order, I experienced something that was a bit of a problem before the chips blew. When I listened to the music, it seemed a bit crackly and distorted. I first tried it with a 12v laptop supply and then with a 24v one. Although the crackle and fuzz was less with the higher voltage, it was still there especially at lower volumes. That leads me to believe I was getting crossover distortion. Has anyone experienced this before? I have had it happen with a few other amps and it's quite annoying.

For those of you who don't know, Manhattan Construction is a building technique that is performed frequently with RF circuits. The idea is to take a bare copper board and use it as the ground plane. Then, you cut small bits of copper board (about 3-5mm square) and glue them onto the copper plane, copper side up. These serve as circuit tie points and will be soldered to. I am doing it at audio mainly because it's faster than burning a board or using a prototyping board. The entire project took me a couple of nights. Well, it did before the amplifier chips blew up.

Ed

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PostPosted: 28 Mar 2014, 06:43 
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Joined: 09 Mar 2014, 04:56
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Location: .nl
This project uses the TDA2050. The TDA2030 datasheet specifies +-18VDC so a 24V supply might blow them up.
Are those laptop supplies switched supplies? From what I read switched supplies require extra care in designing the circuit to prevent supply noise carrying over to the signal.


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PostPosted: 29 Mar 2014, 18:23 
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Joined: 28 Dec 2010, 22:07
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hrs wrote:
This project uses the TDA2050. The TDA2030 datasheet specifies +-18VDC so a 24V supply might blow them up.
Are those laptop supplies switched supplies? From what I read switched supplies require extra care in designing the circuit to prevent supply noise carrying over to the signal.


When you say +/- 18v DC, you really have a 36v supply where the ground level is at 18v. This means that the case, the speaker, and everything else at "ground" is at 0 volts and there is voltage 18 above and 18 below the ground point. If I hooked 24v to it, I would be getting +/- 12v. It should be plenty of voltage which is less than the maximum. When I blew up the chips, I was using it with a 12v (+/- 6v).

It's plausible that noise is getting into the system but I don't think so. Since the supply is bipolar and ground is taken between the rails, the ripple should be equal on both sides of the supply and they should cancel. Maybe that's not how it works here. Although I have capacitors on both sides of the rail, it doesn't mean that noise wasn't getting in there somehow. I'll have to try it out when my new chips come in.

I'm aware that this project uses TDA2050 but I used the 2030 because that is what I had.

Ed

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PostPosted: 04 Apr 2014, 14:42 
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Joined: 03 Apr 2014, 14:32
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Location: USA
Hi everyone (especially Tom)!
After reading this entire thread I'm super excited to start on the TDA2050 amp! I have just finished building one for my circuits class at the uni and needless to say it had left me excited about analog circuits but dissatisfied with the sound. This one seems like the right price to performance ratio :). To get started though does anyone have the eagle files for the amp board and the power supply? My uni can produce boards for pretty cheap. I did see Grega's which was done really well, I just wanted to see if anyone had Tom's or other custom layouts.


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PostPosted: 09 Apr 2014, 20:29 
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Joined: 03 Apr 2014, 14:32
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Location: USA
I have been working on my own power supply board. I was wondering if anyone had any suggestions (this is my first time using Eagle)? Are the positive and negative lines thick enough? I have the bottom layer as the ground plane. My Uni has a pcb mill and I think it'll make this easier. I didn't add any of the component values but I referenced Tom's power supply pcb for the schematic.


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PostPosted: 14 May 2014, 08:37 
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Joined: 02 Mar 2013, 12:13
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hrs wrote:
After thinking about it some more I reccon that if you heed the advise and use a 160VA transformer you'd get ~7% regulation. With some voltage drop over the rectifier would yield about 26VDC which I could imagine is within the unspecified tolerance of the IC.


I just put together the power supply using a 160VA 18-0-18V CT transformer. The voltage output I get is 27VDC. I'm a bit afraid to connect the TDA2050 for the reasons you've mentioned. The spec sheet says "absolute" maximum ratings of +/- 25V.

That being said, no one on these forums complained when using 18-0-18V transformers so I guess it's worth the risk?

On another note, I'll be posting my build next week sometime. I'm pretty excited about it all coming together nicely!


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PostPosted: 18 May 2014, 16:47 
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Joined: 02 Mar 2013, 12:13
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I put together my TDA2050. It sounds really nice. The specs and recommendations from the instructions were used almost exactly as described. I made my own PCBs in Eagle and had them ordered from seeed studio. The back panel cover was made with a laser cutter and I'm going to add laser cut covers and a volume knob as well. I'll upload the final assembly for now, but soon I'll add work-in-progress pics and board schematics for anyone to use if they like.

Attached is the final assembly and back panel:
Attachment:
DSC_0115 copy.jpg

Attachment:
DSC_0114 copy.jpg


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PostPosted: 19 May 2014, 20:20 
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Joined: 28 May 2008, 21:53
Posts: 4530
Location: Winnipeg, CANADA
Nice work. Enjoy the amp and thanks for sharing your photos.

Cheers

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PostPosted: 23 Jun 2014, 22:36 
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Joined: 23 Jun 2014, 22:03
Posts: 2
I 've constructed the circuit of tda 2050 ditto to that in forum , yet i ' m not able to obtain the audio signal at output instead there is a continous hmming and output is about of 5 volt continous
i also used seperate power supply each time 1st i tried with 24-0-24 and the 2nd time i tried with 12-0-12
pls help me out :nuke:


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PostPosted: 24 Jun 2014, 18:31 
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Joined: 12 Mar 2013, 06:07
Posts: 86
Location: Thunder Bay On.
Have you terminated all your grounds to a single point or do you have more than one grounding point?


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