my diy lm3886 amplifier has v- out to speaker

jinkuchi · 8th January 2005, 06:47 PM

help

Its work fine. I connect a fuse 1A before speaker. I listen a music with high level, after that the fuses blow-out 2 channel.

after that,I change volume control from cheap one to alps. and change transistor in pre-amp from 2sc458 to 2sc1815
(I checked it same B C E same type).

my diy lm3886 amplifier has v- out to speaker.
Thank god that I test it with very very cheap speaker.

maybe some things short in circuit when I change volume control.
now I check everythings in circuit is ok.
What to do?

jaudio · 8th January 2005, 07:57 PM

Check to make sure no wire came loose in the power supply

Can you isolate preamp from the amp,that will narrow your search

how much -v at output?

jinkuchi · 9th January 2005, 01:51 AM

It's -42v at the out put.

only 1 channel, other channel is ok.

I think the ic ok.
It happen before! when I test the second amp after finish.
It has dc from output. And after that it normally. I don't understand why it malfuntion.

(this amp have problem is 1st amp).

Last thing I will do is change the ic.
Because its hard to remove heatsink.

jaudio · 9th January 2005, 01:25 PM

What is your amp's supply voltage?

Measure your supply voltage at amp pins

Sheldon · 9th January 2005, 04:15 PM

An open connection in the feedback loop to ground can cause the output to swing all the way to the rail.

Sheldon

8th January 2005, 06:47 PM	#1
jinkuchi diyAudio Member Join Date: May 2004 Location: shinjuku	my diy lm3886 amplifier has v- out to speaker help Its work fine. I connect a fuse 1A before speaker. I listen a music with high level, after that the fuses blow-out 2 channel. after that,I change volume control from cheap one to alps. and change transistor in pre-amp from 2sc458 to 2sc1815 (I checked it same B C E same type). my diy lm3886 amplifier has v- out to speaker. Thank god that I test it with very very cheap speaker. maybe some things short in circuit when I change volume control. now I check everythings in circuit is ok. What to do?

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
DIY smps + LM3886 Car Amplifier	rwaudio	Car Audio	0	30th October 2008 03:06 PM
LM3886 as transconductance amplifier?	squadra	Chip Amps	4	23rd April 2008 10:16 PM
LM3886 based amplifier	russo	Chip Amps	18	4th February 2008 11:27 AM
LM3886 Amplifier help	Jack Bruce	Chip Amps	3	16th January 2007 12:25 AM
LM3886 amplifier	soundNERD	Chip Amps	20	28th September 2003 12:20 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	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

8th January 2005, 07:57 PM	#2
jaudio diyAudio Member Join Date: Oct 2004	Check to make sure no wire came loose in the power supply Can you isolate preamp from the amp,that will narrow your search how much -v at output?

9th January 2005, 01:51 AM	#3
jinkuchi diyAudio Member Join Date: May 2004 Location: shinjuku	It's -42v at the out put. only 1 channel, other channel is ok. I think the ic ok. It happen before! when I test the second amp after finish. It has dc from output. And after that it normally. I don't understand why it malfuntion. (this amp have problem is 1st amp). Last thing I will do is change the ic. Because its hard to remove heatsink.

9th January 2005, 01:25 PM	#4
jaudio diyAudio Member Join Date: Oct 2004	What is your amp's supply voltage? Measure your supply voltage at amp pins

9th January 2005, 04:15 PM	#5
Sheldon diyAudio Member Join Date: Dec 2003 Location: San Diego	An open connection in the feedback loop to ground can cause the output to swing all the way to the rail. Sheldon

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)