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View Poll Results: Was a good idea to use two lm1875 or a big stk chip
Use stk 8 27.59%
use lm1875 21 72.41%
Voters: 29. You may not vote on this poll

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Old 10th January 2013, 05:30 PM   #81
PetruV is offline PetruV  Romania
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It now works ,now lets work toghether on the misbehaving tda 1517 as i make another chanle and i lower it in the case with the transformer
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Old 10th January 2013, 07:10 PM   #82
blu_glo is offline blu_glo  England
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www.nxp.com/documents/data_sheet/TDA1517.pdf

** Heatsink the chip again! **

You will need to re-check your wiring.
Note:

This circuit needs single supply only looks like a car stereo circuit for 12V nominal. So only give it 0V and +12V (+9 to +18V max) connections
For example a 12V ac @ 2A or more transformer, 100V PIV 4A bridge and 4700uF or more supply capacitor (rated 25V or more) The 2200uF supply capacitor shown dotted is absolute minimum necessary. a 100uF 25V capacitor close to the + supply and 0V pins of the IC would also be a good idea.

Pins 2 and 5 to be connetced to 0V
Pins 8 and 7 connected to +12V

The output speaker capacitors on pins 4 and 6 must not be left out as there's 6V dc on the outputs that mustn't get to the speakers. for 8 ohms speakers use at least 1000uF, for 4 ohms use at least 2200uF (in either case rated 25V).

The 100uF on pin 3 is to remove hum you might be able to leave it out in battery situations, but for mains power best to keep it. . More uF in this position = better hum reduction and better transient response.

Last edited by blu_glo; 10th January 2013 at 07:19 PM.
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Old 10th January 2013, 07:36 PM   #83
PetruV is offline PetruV  Romania
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Quote:
Originally Posted by blu_glo View Post
www.nxp.com/documents/data_sheet/TDA1517.pdf

** Heatsink the chip again! **

You will need to re-check your wiring.
Note:

This circuit needs single supply only looks like a car stereo circuit for 12V nominal. So only give it 0V and +12V (+9 to +18V max) connections
For example a 12V ac @ 2A or more transformer, 100V PIV 4A bridge and 4700uF or more supply capacitor (rated 25V or more) The 2200uF supply capacitor shown dotted is absolute minimum necessary. a 100uF 25V capacitor close to the + supply and 0V pins of the IC would also be a good idea.

Pins 2 and 5 to be connetced to 0V
Pins 8 and 7 connected to +12V

The output speaker capacitors on pins 4 and 6 must not be left out as there's 6V dc on the outputs that mustn't get to the speakers. for 8 ohms speakers use at least 1000uF, for 4 ohms use at least 2200uF (in either case rated 25V).

The 100uF on pin 3 is to remove hum you might be able to leave it out in battery situations, but for mains power best to keep it. . More uF in this position = better hum reduction and better transient response.
all conditions respected
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Old 10th January 2013, 07:51 PM   #84
blu_glo is offline blu_glo  England
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Quote:
Originally Posted by PetruV View Post
all conditions respected

John R post #30 seems to suggest if you didn't get the supply pins right the first time the chip may be blown.
Have you got a voltmeter?
- what is the DC voltage between 0V and pin 4?
- what is the DC voltage between 0V and pin 6?

Follow the application circuit on P. 8 of the TDA1517 datasheet posted earlier.
Do not put in additional input or feedback resistors as this upsets the DC stable conditions of this chip.
I think I know what this chip is related to and I had some real fun with those types in my past.....

Last edited by blu_glo; 10th January 2013 at 08:02 PM.
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Old 10th January 2013, 08:12 PM   #85
PetruV is offline PetruV  Romania
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Quote:
Originally Posted by blu_glo View Post

John R post #30 seems to suggest if you didn't get the supply pins right the first time the chip may be blown.
Have you got a voltmeter?
- what is the DC voltage between 0V and pin 4?
- what is the DC voltage between 0V and pin 6?

Follow the application circuit on P. 8 of the TDA1517 datasheet posted earlier.
Do not put in additional input or feedback resistors as this upsets the DC stable conditions of this chip.
I think I know what this chip is related to and I had some real fun with those types in my past.....
My multimeter alwayis gives wrong readings,sgnd pin wasnt conected to the ground the first tinme i tested it
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Old 10th January 2013, 08:29 PM   #86
blu_glo is offline blu_glo  England
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Quote:
Originally Posted by PetruV View Post
My multimeter alwayis gives wrong readings,sgnd pin wasnt conected to the ground the first tinme i tested it
What multimeter is it?
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Old 10th January 2013, 08:33 PM   #87
PetruV is offline PetruV  Romania
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Thumbs up Success

I now have 2 lm1875 modules,and to my whole familys surprise the both work but one of them ,i accidentaly reversed voltage but my psu shut off and my chip lived,if i had used a linear my rather expensive 9ron<equivalent to 2 $> chip would been in flames,also while testing the second amp,the reverse volted one,a big steper motor fell of the shelf for no reason,sud on a black speaker then fell directly on the chip, then directly on my back head,and i kinda blacked out,it took me 5 minutes to realise what happened,and i was desperate to show you my amps so i started to search around the house,could remeber where i put it.
The tda dosent work and i think is dead,otherwise it would have been useless since it wouldnt power up on 5v,
In the pic you can see my tda 2003 powered of 5v working fine,but mono,using a case made out of a vacumcleaner motor.This chip does not get warm at all without heatsink on 5v,So no heatsink needed
Tomorw my friend come to me with a lot of broken pcbs for parts including a radio,a big one which most probably has a chip amp which he wants usb powered,so expect some pictures and questions tomorow morning,and i will ecpect from you quick answers
Have a good day
Ps in the first pic above the transparent box left from my laptop on the shelf the stepper motor sat rhen sud on the black speaker to right picturre,the falling on the chip sitting in the place wher the picture 2 is taken right to my laptop on the corner of the table then on my head as i made the descent for a fallen resistor
Ps 2 the big blue cap is a 10v cap i had given him the name of mr.Mallory,he is usseles due to high esr so no big sparks,but he was cheap only 5 bucks,I think that he brings me luck(he has a smiley face on the back which i turned around accidentaly,he is supposed to face me.
Again have a good one and thanks for your help,especialy blu_glo which has provided me with good help so his name will be written on the pcb
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Last edited by PetruV; 10th January 2013 at 08:42 PM.
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Old 10th January 2013, 08:43 PM   #88
PetruV is offline PetruV  Romania
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Quote:
Originally Posted by blu_glo View Post
What multimeter is it?
Alda avd890d,i have it for a long time
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Old 10th January 2013, 08:49 PM   #89
PetruV is offline PetruV  Romania
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One last question,what does gainclone mean?,sorry for sounding like a noob
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Old 10th January 2013, 08:53 PM   #90
blu_glo is offline blu_glo  England
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I'm surprised you get anythin at all out of the TDA2003 with a 5V supply - the minimum is stated 8V but good if it works.... not much power though before it distorts.

USB power - no really worth it! It's 5V at 0.5A maximum = 2.5W maximum and you have to use special chip to "demand" more than 0.1A so will not give any worthwile power.
You need 12V @ 2A or more, so use a single supply chip like your (expired) TDA one and a 12V plug power supply or make your own for computer audio.... my black monoblocks (one amplifier per case) I posted the pictures are 20W each into 8 ohms would blast your head off playing UNREAL on my old computer, some years back!!

Last edited by blu_glo; 10th January 2013 at 09:10 PM.
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