Graphic Equalizer design HELP needed - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

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
Reply
 
Thread Tools Search this Thread
Old 20th December 2006, 05:49 PM   #1
hrg2112 is offline hrg2112  Canada
diyAudio Member
 
Join Date: Dec 2006
Question Graphic Equalizer design HELP needed

Hello,
I'll attatch two circuits. The first is a bit of a classic
Graphic EQ design.
Q1 : I want to know if the secong circuit would work, using multiple resistors (EQ by increments :-) instead of potentiometers, and if I could use only one array of resistors to do the job. In this example, I drew multiple SPST switches, but it could be jumpers for example. In the two drawings, I put two stages of EQ, but there could be any number.
Q2: What are the best OpAmps (Quality + low power) for the job ?
Q3: If the design works, would the resistor values better be calculated in pseudo logarithmic fashion ?
Thanks !
  Reply With Quote
Old 20th December 2006, 11:24 PM   #2
hrg2112 is offline hrg2112  Canada
diyAudio Member
 
Join Date: Dec 2006
Default Schematic

Click the image to open in full size.
  Reply With Quote
Old 21st December 2006, 03:38 AM   #3
diyAudio Member
 
Join Date: Jul 2003
Location: Dona paula, Goa
Default Quality op-amp

LM4562, it is the best.

Gajanan Phadte
  Reply With Quote
Old 21st December 2006, 06:51 PM   #4
moamps is offline moamps  Croatia
diyAudio Member
 
Join Date: Oct 2002
Location: Croatia
Default Re: Graphic Equalizer design HELP needed

Quote:
Originally posted by hrg2112
Q1 : I want to know if the secong circuit would work, using multiple resistors (EQ by increments :-) instead of potentiometers, and if I could use only one array of resistors to do the job. In this example, I drew multiple SPST switches, but it could be jumpers for example. In the two drawings, I put two stages of EQ, but there could be any number.
Q2: What are the best OpAmps (Quality + low power) for the job ?
Q3: If the design works, would the resistor values better be calculated in pseudo logarithmic fashion ?
A1:
Yes, multiple resistors would work. Some professional mixing consoles use such equalizers.
A2:
This is a tough one as the answer will depend on personal preferences and the budget available.
A3:
When potentiometers are used in professional audio, they are linear pots with center detent. When resistors are used (the way you are using them here), resistor values should preferrably model the S-curve. As an example, for attentuation values ranging from -10 to +10dB in 2dB steps, the following resistor string is used: 150, 180, 270, 270, 270, 270, 270, 270, 180, 150.

Regards,
Milan
  Reply With Quote
Old 21st December 2006, 07:06 PM   #5
Nordic is offline Nordic  South Africa
diyAudio Member
 
Nordic's Avatar
 
Join Date: Sep 2005
http://www.swtpc.com/mholley/Popular...PE_May1974.htm

You may enjoy this ancient article...
  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
5 Band Graphic Equalizer NSLogan Chip Amps 2 17th June 2009 03:52 AM
Polystyrene caps in a graphic equalizer stpa Solid State 3 10th April 2008 03:19 PM
DIY Graphic equalizer? coldfuzion76 Solid State 4 18th March 2008 08:45 AM
Graphic equalizer Buzzy Parts 1 24th July 2007 07:55 PM
Graphic Equalizer Johnny25 Parts 5 29th March 2006 05:33 PM


New To Site? Need Help?

All times are GMT. The time now is 02:18 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