LM3886 Balance Control - 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 14th February 2013, 08:24 PM   #1
diyAudio Member
 
Join Date: Feb 2013
Location: Baton Rouge
Question LM3886 Balance Control

I'm assembling a two-channel (stereo) chipamp LM3886 kit following the user guide and am looking for a simple way to control the balance between L and R channels. For volume control I am using dual-ganged 25K pots on the amplifier input as recommended in the amplifier board schematic. As for balance control, my first thought is to use another pair of dual ganged pots, each between amp IN and GND (a CW turn attenuates one channel while increasing gain on the other, a CCW turn does the opposite) but it is not clear to me how well this will work or whether it is a good idea. Any suggestions?
  Reply With Quote
Old 15th February 2013, 01:05 AM   #2
Minion is offline Minion  Canada
diyAudio Member
 
Join Date: May 2006
Location: Cowican Bay , vancouver island
Generally you would use a dual ganged linear pot with one gang wired backwards so that when you turn the pot one channel increases in volume and the other channel decreases in volume ......

Cheers
  Reply With Quote
Old 15th February 2013, 07:46 PM   #3
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
You can add a balance control in front of the volume pot. See fig 4 here,
Hi-Fi Preamplifier
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote
Old 15th February 2013, 10:00 PM   #4
DUG is offline DUG  Canada
diyAudio Member
 
Join Date: Jan 2003
Location: mississauga ontario canada
Quote:
Originally Posted by Mooly View Post
You can add a balance control in front of the volume pot. See fig 4 here,
Hi-Fi Preamplifier
That is the way I do it...saw it in a '70 stereo...used it ever since.
__________________
Doug We are all learning...we can all help
"You can't stop the signal, Mal. Everything goes somewhere..."
  Reply With Quote
Old 18th February 2013, 03:12 PM   #5
diyAudio Member
 
Join Date: Feb 2013
Location: Baton Rouge
Thanks for the ideas. I'll let you know how it turns out.
  Reply With Quote
Old 19th February 2013, 05:22 PM   #6
diyAudio Member
 
Join Date: Mar 2006
Location: Georgia USA
Look at LM1036 For the controls to your amp
  Reply With Quote
Old 20th February 2013, 02:34 PM   #7
diyAudio Member
 
Join Date: Feb 2013
Location: Baton Rouge
Thanks, I was not aware of this IC. TI is sending me a free sample.
  Reply With Quote
Old 20th February 2013, 03:01 PM   #8
diyAudio Member
 
KatieandDad's Avatar
 
Join Date: Nov 2011
Location: UK
There are some very simple ways to implement a balance control if you don't want to add extra amplification into your design.

The simplest way is to use a dual linear track pot with each half wired in reverse to the other (ie one side is increasing in resistance as the other is reducing). One side can be connected from the wiper of the Left volume pot to ground and the other side from the wiper of the Right.

With the "Balance Pot" in its centre position, both sides will be attenuated equally. As you move the pot off centre one side will attenuate more than the other, and at the extreme ends of the pot one channel will disappear completely.

You will lose a bit of gain but that can be recouperated in the other stages.
  Reply With Quote
Old 22nd February 2013, 07:14 PM   #9
diyAudio Member
 
Join Date: Feb 2013
Location: Baton Rouge
Thanks, your suggestion seems to validate my original idea it seems. This amp is not actually going to be used for audio but for a chemistry experiment driving a pair of Helmholtz coils. I'll report back my results.
  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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Balance control R Values Audionorth Analog Line Level 1 14th March 2010 11:39 PM
software balance control loninappleton PC Based 7 21st September 2009 05:49 PM
How to wire a balance control Bama Slamma Solid State 8 13th September 2007 05:15 AM
Balance LM3886 not working Ipanema Chip Amps 6 9th March 2006 02:20 AM
Balance control 2Bak Pass Labs 4 11th July 2002 08:07 AM


New To Site? Need Help?

All times are GMT. The time now is 03:03 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