Tone Control - Volatage range for TL072/LF252-N - Page 4 - diyAudio
Go Back   Home > Forums > Source & Line > Analog Line Level

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc.

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 18th May 2013, 10:31 AM   #31
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
You have to try a new chip then although its worth checking any feedback components as these set the gain.
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote
Old 18th May 2013, 12:06 PM   #32
diyAudio Member
 
Join Date: Apr 2013
So tell me again, which are the feedback components?

Click the image to open in full size.
  Reply With Quote
Old 18th May 2013, 12:21 PM   #33
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
R1/R2 and C6.
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote
Old 18th May 2013, 12:23 PM   #34
diyAudio Member
 
Join Date: Apr 2013
For the first amp its R1, R2 and C6 and for the second amp R3, R4 and C7?
  Reply With Quote
Old 18th May 2013, 04:22 PM   #35
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Yep, but its so simple a circuit that its just to much of a coincidence that all this has happened from experimenting with the preamp. Something has happened somewhere down the line.
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote
Old 27th May 2013, 05:47 AM   #36
diyAudio Member
 
Join Date: Apr 2013
Bump!

One of the channels is definately fried. I changed all the feedback components to no avail.
_______________________

Regarding this schematic:
Click the image to open in full size.

I see that the first op amp is non-inverting and after the tone control stage the op amp is inverting. Do I need to add another inverting op amp to recover the signal?
  Reply With Quote
Old 27th May 2013, 06:33 AM   #37
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
If the phase reversal bothers you then all you need do is reconfigure the first opamp as an inverting buffer. Just ground pin 3 and apply the input to pin 2 via the input cap and a series 10K resistor. Then add a new 10K resistor between pin 2 and pin 1.
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote
Old 27th May 2013, 06:42 AM   #38
diyAudio Member
 
Join Date: Apr 2013
Is there any audible difference between the two configurations?
  Reply With Quote
Old 27th May 2013, 06:48 AM   #39
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Try it

All you have to do is swap polarity of both your speaker leads. That does exactly the same.
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote
Old 27th May 2013, 06:54 AM   #40
diyAudio Member
 
Join Date: Apr 2013
I notice a little bass boost but other than that I can't tell any difference.

You're right Mooly, I fried one channel of the chipamp together with one of the op amps when I was experimenting with it. I replaced them and everything sounds nice now except for a little distortion. I'm planning use the old chip in BTL mode for a sub.
  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
Tone control argonrepublic Solid State 11 13th November 2011 01:32 AM
To tone control or not to... dagerman Tubes / Valves 12 27th June 2011 06:15 AM
Tone control argonrepublic Solid State 0 28th February 2010 12:12 AM
Tone control ckt using TL072 shahraj Multi-Way 2 13th October 2009 04:52 PM
i need preamp schematics w/o tone control or volume control hernanstafe Parts 7 30th January 2008 03:12 AM


New To Site? Need Help?

All times are GMT. The time now is 11:21 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