3 BAND TONE CONTROL

Reno1 · 14th September 2011, 06:16 PM

Hi I want to use this circuit after my phono preamp but I was wondering would swapping the smd resistors to a more conventional number have any ill effect. For example swapping the 4.02k resistor to 4k the same goes for 1.91k, 5.36k 19.1k any suggestions ?

Leon08 · 14th September 2011, 08:58 PM

Resistors and all parts have some tolerances, for instance 5% or 10%.So this means that they are never the same value and any resistor is slightly different.I also have never seen a 4.02k resistor.This is not normal resistor wich you can buy.

stratus46 · 15th September 2011, 02:16 AM

Quote:

Originally Posted by Leon08

Resistors and all parts have some tolerances, for instance 5% or 10%.So this means that they are never the same value and any resistor is slightly different.I also have never seen a 4.02k resistor.This is not normal resistor wich you can buy.

Those are all standard 1% values.

Resistor Values E6 E12 E24 E48 E96 E192

You can buy them at DigiKey and Mouser and likely Farnell (and many others). I used to use E96 values exclusively at a former job.

G²

Leon08 · 12:24 PM

4k and 4,02k are pretty much the same.I would not care about the exact values and replace them with the next best.
This resistors set the gain of the op-amps and have no impact on tone.

Reno1 · 15th September 2011, 08:16 PM

Thanks for the reply appreciate it

mickeymoose · 15th September 2011, 11:59 PM

These are filters that need fairly accurate resistor (1%) and capacitor (2-5%) tolerance values. You could simulate them with free software like TI's FilerPro or LT's FilterLab and see what the effects are on changing parts values. E

Reno1 · 21st September 2011, 12:14 PM

Thanks for all the help guys, I have got just one more quick question. I have fount another version of this eq with another opamp on the output and would like to no what it does and if its necessary thanks.

Reno1 · 21st September 2011, 12:19 PM

Thanks for the help guys, just another quick question. I have fount another version of this EQ with a extra opamp on the output and would like to know what it does and if its necessary thanks.

mickeymoose · 21st September 2011, 04:00 PM

Look at the circuit:
High and low filters go through a non-inverting amp, are summed at U23B, inverting amp U23B and inverted again in U23A. Good!
Mids go through inverter U24A and come out inverted after U23A
Good, bad? Build it, you judge. E

stratus46 · 22nd September 2011, 07:40 AM

Quote:

Originally Posted by Reno1

Thanks for the help guys, just another quick question. I have fount another version of this EQ with a extra opamp on the output and would like to know what it does and if its necessary thanks.

It adds a phase inversion but as MickeyMoose pointed out the mid has an inversion that the other two do not have. Does this EQ have a 'flat' position? It would seem that if the slopes between mid / low and mid / high don't match exactly it will never have a 'flat' mode. It seems to be the oddest EQ configuration I've ever seen. Have you looked into parametric equalizers or even plain old graphics?

G²

15th September 2011, 12:20 PM	#4
Leon08 Banned Join Date: Sep 2010 Location: at Home	4k and 4,02k are pretty much the same.I would not care about the exact values and replace them with the next best. This resistors set the gain of the op-amps and have no impact on tone. Last edited by Leon08; 15th September 2011 at 12:24 PM.

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
2-Band Baxandall Tone Control	maouna	Solid State	27	21st January 2011 08:13 PM
2 band transistor tone control	maouna	Solid State	0	31st October 2010 08:58 AM
Passive 2 band tone stack for guitar	SouPortugues	Instruments and Amps	9	11th August 2009 03:35 PM
i need preamp schematics w/o tone control or volume control	hernanstafe	Parts	7	30th January 2008 03:12 AM
3 band tone ,BAXANDALL ????? bass treble mid?????	prorms	Solid State	0	4th September 2006 05:23 AM

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

14th September 2011, 08:58 PM	#2
Leon08 Banned Join Date: Sep 2010 Location: at Home	Resistors and all parts have some tolerances, for instance 5% or 10%.So this means that they are never the same value and any resistor is slightly different.I also have never seen a 4.02k resistor.This is not normal resistor wich you can buy.

15th September 2011, 08:16 PM	#5
Reno1 diyAudio Member Join Date: Jun 2011	Thanks for the reply appreciate it

15th September 2011, 11:59 PM	#6
mickeymoose diyAudio Member Join Date: Nov 2008	These are filters that need fairly accurate resistor (1%) and capacitor (2-5%) tolerance values. You could simulate them with free software like TI's FilerPro or LT's FilterLab and see what the effects are on changing parts values. E

21st September 2011, 12:14 PM	#7
Reno1 diyAudio Member Join Date: Jun 2011	Thanks for all the help guys, I have got just one more quick question. I have fount another version of this eq with another opamp on the output and would like to no what it does and if its necessary thanks.

21st September 2011, 04:00 PM	#9
mickeymoose diyAudio Member Join Date: Nov 2008	Look at the circuit: High and low filters go through a non-inverting amp, are summed at U23B, inverting amp U23B and inverted again in U23A. Good! Mids go through inverter U24A and come out inverted after U23A Good, bad? Build it, you judge. E

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