lm1875 fizzing away probelm - Page 2

PetruV · 5th January 2013, 08:56 AM

I think the chip is dead it makes a very loud thinking noise even when its not hooked up to my computer,when i conect it to my computer the noise still continues and distorts the music

picowallspeaker · 5th January 2013, 09:10 AM

I wouldn't use those ceramic capacitors . They are good for suppressing HF noise on the supply line, and they do the same duty well for reducing bandwidth at input (LP filter) of amplifier .
Use plastic dielectric ones...polyester, styrene, ecc for a Vl of 63-100 V.

PetruV · 5th January 2013, 09:43 AM

Quote:

Originally Posted by picowallspeaker

I wouldn't use those ceramic capacitors . They are good for suppressing HF noise on the supply line, and they do the same duty well for reducing bandwidth at input (LP filter) of amplifier .
Use plastic dielectric ones...polyester, styrene, ecc for a Vl of 63-100 V.

Oh thats why it sounded not bassy when it worked!

PetruV · 5th January 2013, 07:25 PM

Can someone post a good schematic here,with not a lot of components and mostly with the components that are on the schematic just swaped around

bobodioulasso · 5th January 2013, 09:58 PM

http://www.ti.com/lit/ds/symlink/lm1875.pdf

PetruV · 6th January 2013, 08:16 AM

I think il use danielwritesbac veroboard version,but my soldering iron burned up since i worked too much with it since i was desperate to her the amp,in coupe minutes il go to the shop with my dad and i will return most probably succesfull in one hour

PetruV · 6th January 2013, 10:34 AM

got a new soldering iron and its so good wow,much better than my old one

picowallspeaker · 6th January 2013, 11:08 AM

You can raise the value of the input capacitor .
That will increase bass . 1 till 3 uF are ok

PetruV · 6th January 2013, 01:05 PM

DSCF2873.jpg
This is the schematic im building now,i got a new soldering iron and its so awesome!1!!1

bobodioulasso · 6th January 2013, 02:38 PM

This one is now symmetrical supply.

View Poll Results: Was a good idea to use two lm1875 or a big stk chip
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5th January 2013, 08:56 AM	#11
PetruV diyAudio Member Join Date: Dec 2012 Location: Bucuresti	I think the chip is dead it makes a very loud thinking noise even when its not hooked up to my computer,when i conect it to my computer the noise still continues and distorts the music

5th January 2013, 09:10 AM	#12
picowallspeaker diyAudio Member Join Date: Apr 2007	I wouldn't use those ceramic capacitors . They are good for suppressing HF noise on the supply line, and they do the same duty well for reducing bandwidth at input (LP filter) of amplifier . Use plastic dielectric ones...polyester, styrene, ecc for a Vl of 63-100 V.

5th January 2013, 07:25 PM	#14
PetruV diyAudio Member Join Date: Dec 2012 Location: Bucuresti	Can someone post a good schematic here,with not a lot of components and mostly with the components that are on the schematic just swaped around

5th January 2013, 09:58 PM	#15
bobodioulasso diyAudio Member Join Date: May 2008	http://www.ti.com/lit/ds/symlink/lm1875.pdf

6th January 2013, 08:16 AM	#16
PetruV diyAudio Member Join Date: Dec 2012 Location: Bucuresti	I think il use danielwritesbac veroboard version,but my soldering iron burned up since i worked too much with it since i was desperate to her the amp,in coupe minutes il go to the shop with my dad and i will return most probably succesfull in one hour

6th January 2013, 10:34 AM	#17
PetruV diyAudio Member Join Date: Dec 2012 Location: Bucuresti	got a new soldering iron and its so good wow,much better than my old one

6th January 2013, 11:08 AM	#18
picowallspeaker diyAudio Member Join Date: Apr 2007	You can raise the value of the input capacitor . That will increase bass . 1 till 3 uF are ok

6th January 2013, 01:05 PM	#19
PetruV diyAudio Member Join Date: Dec 2012 Location: Bucuresti	DSCF2873.jpg This is the schematic im building now,i got a new soldering iron and its so awesome!1!!1

6th January 2013, 02:38 PM	#20
bobodioulasso diyAudio Member Join Date: May 2008	This one is now symmetrical supply.