TDA7439 tone control IC any good? - diyAudio
Go Back   Home > Forums > Source & Line > Analog Line Level
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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 22nd May 2014, 03:56 AM   #1
diyAudio Member
 
pulexirritans's Avatar
 
Join Date: Nov 2007
Default TDA7439 tone control IC any good?

I have a project with a LM1036 that I would like to replace with something less noisy. I'm pretty sure I'm going to try the TDA7439, but before I do I thought I'd ask here. Any other suggestions for a tone control IC are welcome.

TDA7439 datasheet is here:

http://www.st.com/web/en/resource/te...CD00010668.pdf

And the noisy LM1036:

http://www.ti.com/lit/ds/symlink/lm1036.pdf

Thanks!
  Reply With Quote
Old 22nd May 2014, 07:04 AM   #2
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 137
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Looks very similar to TDA7318 which I used many, many moons ago. I noticed no problems with noise. This part has a mid-range control which the 7318 lacks.
__________________
The smart way to keep people passive and obedient is to strictly limit the spectrum of acceptable opinion, but allow very lively debate within that spectrum. Chomsky
  Reply With Quote
Old 22nd May 2014, 02:21 PM   #3
diyAudio Member
 
pulexirritans's Avatar
 
Join Date: Nov 2007
Quote:
Originally Posted by abraxalito View Post
Looks very similar to TDA7318 which I used many, many moons ago. I noticed no problems with noise. This part has a mid-range control which the 7318 lacks.
Thanks! That does indeed look similar to the tda7439. Same S/N ratio of 106db, and looking at the datasheet it looks like they're closely related.
  Reply With Quote
Old 24th May 2014, 05:10 PM   #4
diyAudio Member
 
Join Date: Apr 2012
Location: Italy
I've made an amplifier based on this chip (see this post). I found the tone control (especially mid range) quite aggressive, but it could be due to the values I've choosen for external components (or maybe 2dB steps are too large). Leaving the controls flat, the sound is very good and the inputs switch and volume control work very well.

One thing that I don't understand from the datasheet is the internal structure of the mid and bass tone controls; datasheet shows in and out pins where to connect external components, but I can't figure out how the active part works. I found ST datasheets are always too poor of information.Can someone explain me? Thanks.
  Reply With Quote
Old 24th May 2014, 07:30 PM   #5
diyAudio Member
 
pulexirritans's Avatar
 
Join Date: Nov 2007
Quote:
Originally Posted by pierluigiugolotti View Post
I've made an amplifier based on this chip (see this post). I found the tone control (especially mid range) quite aggressive, but it could be due to the values I've choosen for external components (or maybe 2dB steps are too large). Leaving the controls flat, the sound is very good and the inputs switch and volume control work very well.

One thing that I don't understand from the datasheet is the internal structure of the mid and bass tone controls; datasheet shows in and out pins where to connect external components, but I can't figure out how the active part works. I found ST datasheets are always too poor of information.Can someone explain me? Thanks.

I don't think you need to know how the active part works, you just need to use the equations on p. 9 to get the behavior that you want. Just choose the gain (Av) and Q that you want and then solve each equation on p. 9 starting at the top. Ri is fixed, so you don't even need to choose a value to start. For the midrange Ri = Rm = 25k

I would also lower the Q in addition to the gain. With high Q, the high gain settings are useless. From the equation for Q on p. 8 it looks like they chose a Q of 1.5, I would choose something lower like 1 or maybe even less?

Btw, what did you think about the noise of the TDA7439 with the gain cranked up? This is my main complaint against the LM1036.
  Reply With Quote
Old 25th May 2014, 01:56 AM   #6
diyAudio Member
 
Join Date: Apr 2012
Location: Italy
Quote:
Originally Posted by pulexirritans View Post
I don't think you need to know how the active part works, you just need to use the equations on p. 9 to get the behavior that you want. Just choose the gain (Av) and Q that you want and then solve each equation on p. 9 starting at the top. Ri is fixed, so you don't even need to choose a value to start. For the midrange Ri = Rm = 25k
Yes, this is clear. I was just inquiring on how the stage work.

Regarding the noise, with the input gain stage and volume at 0dB, the amp is totally silent. With my hear just in front of the tweeter the noise is almost inaudible.

My power stage needs 1V for 60W output, so, with a -10dBV signal I have to set the input gain at +10dB. Even so, there's no audible noise, but sourcing input will destroy my hears, so... an exellent SNR in my opinion.

Regards.
  Reply With Quote
Old 25th May 2014, 06:53 AM   #7
diyAudio Member
 
pulexirritans's Avatar
 
Join Date: Nov 2007
Quote:
Originally Posted by pierluigiugolotti View Post
Yes, this is clear. I was just inquiring on how the stage work.
Sorry, I really misinterpreted that. I think the last two paragraphs in the data sheet description are about as far as you're going to get without talking to someone at st-micro...

Quote:
Originally Posted by pierluigiugolotti View Post
Regarding the noise, with the input gain stage and volume at 0dB, the amp is totally silent. With my hear just in front of the tweeter the noise is almost inaudible.

My power stage needs 1V for 60W output, so, with a -10dBV signal I have to set the input gain at +10dB. Even so, there's no audible noise, but sourcing input will destroy my hears, so... an exellent SNR in my opinion.

Regards.
Awesome, this is exactly what I want to hear. Thank you!

Last edited by pulexirritans; 25th May 2014 at 07:07 AM.
  Reply With Quote
Old 29th September 2015, 03:04 AM   #8
diyAudio Member
 
Join Date: Aug 2010
Default Arduino C Code for the TDA7439

If you are using an Arduino to drive the IC you can find an almost complete implementation of the code needed at:

https://github.com/ahuxtable/TDA7439
  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
Looking for Very good tone control schem. vytas Solid State 27 22nd March 2012 12:25 PM
Tone control - good diagram needed Jap Tubes / Valves 4 31st January 2011 11:11 PM
i need preamp schematics w/o tone control or volume control hernanstafe Parts 7 30th January 2008 03:12 AM
Digitally Controlled Volume, Tone IC ?? metal Chip Amps 55 8th August 2005 11:35 AM


New To Site? Need Help?

All times are GMT. The time now is 12:46 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Copyright 1999-2016 diyAudio

Content Relevant URLs by vBSEO 3.3.2
Wiki