tda 2050 gainclone / balanced input?

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I just had to check what all the fuzz was about, so I built a gainclone (awful looking test-rig only -> I will not post any pics) based on the tda2050 chip. The circuit is Thorsten's, without output resistor and grounded "-" input.

I hate to admit it, but it sounds really good!!! :(

What I'm wondering about is this:

Wouldn't it be nice to have balanced input on these snazzy little things?

I assume averyone and his dog will be building clones this winther, and many of us (passlabs fan's anyhow) have a rather nice BOSOZ just standing there...

I am not shure how to implement this however, so if someone has any ideas, please share!

Also, I wish you all a happy new diy year!

:)
 
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Joined 2002
Can't help you with the balanced thing but you reminded me of a prehistoric gainclone. Nobody even thought of listening seriously to this IC amps that time. I made a few for others that were content with it. This one was in my drawer. Maybe I could give it another chance ( without the OSCONS). ;)
 

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Mad_K said:
I just had to check what all the fuzz was about, so I built a gainclone (awful looking test-rig only -> I will not post any pics) based on the tda2050 chip. The circuit is Thorsten's, without output resistor and grounded "-" input.

I hate to admit it, but it sounds really good!!! :(
Also, I wish you all a happy new diy year! :)
Glad someone else is thinking of TDA2050
It is based on the very much used TDA2040
also a nice chip! and then you have 2030, 2020 ......

Difference is that TDA2050 is in Class AB.
While the others is to be considered Class B
TD2050 uses more idle current in Output.
And it can also deliver slightly more Watts.
Price of the CHIP is next to NOTHING. Very low cost!

On this page you can download datasheets on all these Chips
TDA2050 PDF and other ST chips for Audio
-----------------------------------------------------

This guy uses 2050 in his subwoofers
YB's Audio Projects - nice looking LSPs!!!!!

See "DIY" on this page. you can bridge two TDA2050 to get 64 Watts
A LOT of Audio Music Links
------------------------------------------------------------------

Much more is to be said about Power Amplifier in Chip.
They are democratic in that way that
Most DIY-selvers can build with them,
NOT only the amplifier specialists, that uses transistors or tubes.

/halojoy - the specialist :D
 
Bridge Amplifiers

Found this page.
About Bridge Amplifiers
One promising i.c. I found is the TDA2050 which works with plus and minus 25 volt supplies, and can deliver 50 watts 'music power' into a 4 ohm load. The peak current is limited to 5 amps, which is plenty for a single ended amplifier, but in a bridge, with 20 volt peak output voltage from each half, the peak voltage across the load is 40 volts, giving a requirement for 10 amps into a 4 ohm speaker impedance. There are no doubt i.c. amplifiers available capable of this current, but they are not likely to be cheap. One answer is to add external power transistors to the i.c. To take advantage of the internal protection circuits we must ensure that these transistors can only increase output current by a fixed factor, In the case of the TDA2050 we want to double the maximum current from 5 amps to 10 amps.
Bridge Amplifiers
 
it's made the same way as peter daniel's clones, but not by 1/1000 as beautiful, because I only wanted to hear it run with this
circuit:

http://home.attbi.com/~greggbaker/invertedLM3875.gif

i have also tried the "typical application" circuit, wich is nowhere as good.

i'm going to try balanced, thinking I will add a 47k ohm to ground (which I use instead of the 100k pot) and a 10k ohm in series with the + input. This way one could also have the absolute phase correct..
 
Mad_K said:
it's made the same way as peter daniel's clones, but not by 1/1000 as beautiful, because I only wanted to hear it run with this
circuit:

http://home.attbi.com/~greggbaker/invertedLM3875.gif

i have also tried the "typical application" circuit, wich is nowhere as good.

i'm going to try balanced, thinking I will add a 47k ohm to ground (which I use instead of the 100k pot) and a 10k ohm in series with the + input. This way one could also have the absolute phase correct..

The circuit on that URL you mentioned was Thorsten's. Someone on this thread asked that.

By typical application you mean that on the data page?

I just don't get it why you would be phase correct by adding that 10K resistor, which I think has to be there anyway. I thought you could change the phase only by changing the output wiring to the speaker from the two bridged amps.


Carlos
 
Mad_K said:
What I'm wondering about is this:
Wouldn't it be nice to have balanced input on these snazzy little things?

I am not shure how to implement this however, so if someone has any ideas, please share!
Also, I wish you all a happy new diy year! :)
Yes, it could be nice using two TDA2050 in balanced configuration.
Especially if you have soundsources that have balanced outputs.

:cool: Sorry to say, I am not sure how to set up the circuit.
And I doubt anyone have a suggestion on paper for us.
This indicates their level of knowledge of this matter. :D :D

My advice:
Draw up your idea in a circuit. Put the diagram here.
If noone complains (99% someone will) - then try it out! ;)
Happy New Year, Mad_K

/halojoy - the one and only :angel:halo:angel: there is
 
halojoy said:

Yes, it could be nice using two TDA2050 in balanced configuration.
Especially if you have soundsources that have balanced outputs.

:cool: Sorry to say, I am not sure how to set up the circuit.
And I doubt anyone have a suggestion on paper for us.
This indicates their level of knowledge of this matter. :D :D

My advice:
Draw up your idea in a circuit. Put the diagram here.
If noone complains (99% someone will) - then try it out!

First of all, a balanced connection for these amp chips is very easy. You just have a look at how Marchand Electronics wires their LM3386s to make the PM21 amp:

http://www.marchandelec.com/ftp/pm21man.pdf

The pcb layout could be improved too, following the shortest path route. Like putting the gain resistors directly between the IC pins and so on.


Carlos
 
carlmart said:
First of all, a balanced connection for these amp chips is very easy. You just have a look at how Marchand Electronics wires their LM3386s to make the PM21 amp:
http://www.marchandelec.com/ftp/pm21man.pdf
Carlos

You mean like this carlmart?
Isn't this diagram a little TOO SIMPLE
It can raise more Questions, than it answers.
-----------------------------------------------------

What would be a - bridge of 2 TDA2050 - circuit?

Anyone?

/halo
 

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Thanks Carlos!

This is what I'm talking about!!!

Halo -you can not have read the whole manual! (Could you post the figure "PM 21 Circuit diagram", as I can't ripp pdf's ...please?)

Forget about the tda2050; it doesn't matter much which chip we're talking about, as they can all be implemented the same way.

It was as I suspected; just make the impendances on both inputs the same, and drive it balanced!!!

I'm going to try this sometime during the winther, when I can get to the project where I make myself a gainclone... Too busy on other projects right now ;)

I think I wil use the BB OPA548/OPA549 or LM3886 for this...
 
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It can Capture any other program's Window
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see link in post above

It can capture Window or Active window or Whole desktop (Screen)

With Capture you can get even pictures that are "protected" from download

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I have already recommended this program several times.
best freeware graphic viewer

/halojoy repeat himself
 
Capture in pdf

Mad_K said:


BTW, how do you ripp pdf's like that? (Not with a scanner, I hope...)

The suggestion Halojoy gives is very useful, particularly if it's good for capturing images from pcb programs, which I would like to do and don't know how.

But for pdf is much easier. Just download Acrobat reader, version 5.05 or 5.1, and use the capture capabilities they now have.

You can capture text or images. There's a catch for images though: the larger you make the image (using + view), the better the image but also larger the file.


Carlos
 
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