- 197 mV offfset on LA 4663 - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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
Reply
 
Thread Tools Search this Thread
Old 12th April 2005, 07:49 AM   #1
G33/33 is offline G33/33  Indonesia
diyAudio Member
 
G33/33's Avatar
 
Join Date: Dec 2004
Location: Djakarta
Default - 197 mV offfset on LA 4663

Friends,

I build an amp with LA 4663, and have - 197 mV offset on both channel. The schematic is taken from datasheet without any modification, only add a 10K potensiometer before input cap. What should I do to lowering the offset below 50 mV ?

I have search the archieve, but no one using this chip.

rgds,
Gede
  Reply With Quote
Old 12th April 2005, 10:26 AM   #2
Leolabs is offline Leolabs  Malaysia
diyAudio Member
 
Leolabs's Avatar
 
Join Date: Dec 2004
Location: Bukit Mertajam
Send a message via MSN to Leolabs
what kind of chip is this????Do u operate it with dual voltage supply???
  Reply With Quote
Old 12th April 2005, 03:43 PM   #3
rinox is offline rinox  Italy
diyAudio Member
 
Join Date: Oct 2004
197 mV is simply nothing, don't worry about this offset.
  Reply With Quote
Old 13th April 2005, 03:37 AM   #4
G33/33 is offline G33/33  Indonesia
diyAudio Member
 
G33/33's Avatar
 
Join Date: Dec 2004
Location: Djakarta
Quote:
Originally posted by Leolabs
what kind of chip is this????Do u operate it with dual voltage supply???
No, this chip is designed for single supply.
You can download it's d/s from www.alldatasheet.co.kr or from Sanyo website. It sounds good enough for my ears. The output stage looks like a balance amp but may be i'm wrong about this.


Quote:
Originally posted by rinox
197 mV is simply nothing, don't worry about this offset.
Well, i can't confinced myself that 197 mv offset is nothing. Especially after reading Joe R posting about DC offset




rgds,
Gede
  Reply With Quote
Old 13th April 2005, 07:26 AM   #5
Tim__x is offline Tim__x  Canada
diyAudio Member
 
Join Date: Jun 2004
Location: Edmonton area, Alberta
Looking at the datasheet, this chip runs into a BTL. Are you measuring the offset between output pins, or from one output to ground? Between outputs on one channel is the way you should be measuring it.
  Reply With Quote
Old 13th April 2005, 07:45 AM   #6
G33/33 is offline G33/33  Indonesia
diyAudio Member
 
G33/33's Avatar
 
Join Date: Dec 2004
Location: Djakarta
Quote:
Originally posted by Tim__x
Looking at the datasheet, this chip runs into a BTL. Are you measuring the offset between output pins, or from one output to ground? Between outputs on one channel is the way you should be measuring it.
Hi Tim,

I measure between output ( Output + and Output - ) on one channel, not ground.
If i measure to ground, it would be around 6,8 V with 15V supply, exactly as datasheet show.

rgds,
Gede
  Reply With Quote
Old 13th April 2005, 10:11 AM   #7
diyAudio Member
 
runebivrin's Avatar
 
Join Date: Jul 2003
Location: Huddinge, Sweden
Send a message via MSN to runebivrin
The spec sheet says the offset can be anything from -300mV to +300mV, so if you want lower offset you'll either have to change chip, or add a trim pot on the input to inject a small compensatory DC voltage.

Rune
__________________
Do wizards use spell checkers?
  Reply With Quote
Old 14th April 2005, 01:32 AM   #8
G33/33 is offline G33/33  Indonesia
diyAudio Member
 
G33/33's Avatar
 
Join Date: Dec 2004
Location: Djakarta
[QUOTE]Originally posted by runebivrin
[B] if you want lower offset you'll either have to change chip, or add a trim pot on the input to inject a small compensatory DC voltage.


Hi Rune,

Do you mean add a trimpot after the input caps in series to the input pin or to Ground ?

I won't change the chip because I want to learn more on how to solve offset problem with chip amp

Gede
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 04:25 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2