Balance control-where in the preamp chain should it go? - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

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
Thread Tools Search this Thread
Old 20th July 2015, 02:25 AM   #1
rif is offline rif  United States
Neither a cowbow nor dog owner
diyAudio Member
rif's Avatar
Join Date: Jan 2003
Location: Southern NJ
Default Balance control-where in the preamp chain should it go?

Ok, so I can't get this out of my head and it hurts. I don't even plan on building a preamp anytime soon. Yes, I know things like balance and tone adjustments are out of style but I'm thinking and learning still.

From what I see a preamp is usually input selector -> volume pot -> differential input -> gain stages -> output.

Where would one inject a balance control?
  Reply With Quote
Old 20th July 2015, 02:41 AM   #2
rayma is offline rayma  United States
diyAudio Member
Join Date: Apr 2011
Location: Wisconsin
Originally Posted by rif View Post
From what I see a preamp is usually input selector -> volume pot -> differential input -> gain stages -> output.
Where would one inject a balance control?
Between the input selector and the volume control is best.
  Reply With Quote
Old 20th July 2015, 04:15 AM   #3
diyAudio Member
Join Date: Jul 2013
Trying to be helpful, I offer that you should consider the entire signal path, the circuits you are using to control it, and the end goal of a balance control, which is to allow an easy to control gain difference between channels. You can put any of this anywhere, maybe you can fold this function into other parts of the circuit that already exist, maybe it has to be an isolated stage… and so on.

One of the goals of 'nice' analog circuit design, as I see it, is the ability to provide all of the behavior / functionality that you need, while using a minimal set of components and hardware to accomplish that. IMHO, analog always seems to work better when you use minimal circuitry (which is of course able to provide the functions and features needed).

As an example, let's say you have a programmable attenuator style volume control. Your balance control could simply be a gain offset sent to the left and right channel gains, added to the volume control setting. In this case, you don't need a separate circuit to do balance, you just use one variable gain stage to do both volume and balance.

If you're using mechanical pots or mechanically switched attenuators, then you need a separate volume control and a separate balance control, but maybe the two circuits can be blended together to avoid a buffer stage. For example, if you have a volume control pot, you can add a balance pot before or after so that the resistances work out right. If you can't do that, you need to add a buffer between the controls, but again, this should be avoided, and is probably avoidable without much hassle.

I know this is going to partly add to your confusion by providing even more options, when you seem to want fewer, but it's the right way to think about analog circuit design IMHO. Think carefully about how you can provide the function you need with what you already have, or with some otherwise compact and simple (i.e. elegant… ;-) set of circuitry.

Best of luck!
  Reply With Quote
Old 20th July 2015, 05:08 AM   #4
Bare is offline Bare  Canada
diyAudio Member
Join Date: Dec 2001
Location: vancouver
Erm... you could do like many others have done: Insert A volume Pot (type is Your choice but Stepped Attenuators is Mine) at.. EACH.. input,
creating two volume controls.
Then just turn them individualy for balance purposes.
Easy AND elegant.
  Reply With Quote


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
Preamp with active gain and Balance control aluks Solid State 1 24th February 2015 01:09 PM
Balance control? Michael Bean Analog Line Level 1 16th December 2014 04:43 PM
Balance control R Values Audionorth Analog Line Level 1 14th March 2010 10:39 PM
DSelf Precision Preamp Balance Control John10 Solid State 4 10th February 2004 04:07 PM
Balance control 2Bak Pass Labs 4 11th July 2002 07:07 AM

New To Site? Need Help?

All times are GMT. The time now is 07:41 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2