LM3886 is good enough for PA? - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 January 2013, 10:07 PM   #1
diyAudio Member
 
Join Date: Aug 2004
Location: Argentina
Default LM3886 is good enough for PA?

Hi guys, i already build 4 amplifiers using lm3886, lm4780 and tested other ones, i really like how they sound, just want to know if will be OK to use 2 lm3886 chips in parallel to run 2x100watts stereo amps to use in PA systems?

i always used it at home for pc and for Movie theater, was thikning abt build some amps for a friends and he can use it to play music outdoor.

Maybe paralleling 2 or 3 chips to get at least 100-150w.

was thinking abt use that because are really easy to build (more than use transistors and mosfets, and maybe cheaper)

Thanks for advance.
  Reply With Quote
Old 20th January 2013, 10:15 PM   #2
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Hi,

Some form of limiting / compression would probably be very useful for a PA amplifier.

rgds, sreren.
__________________
There is nothing so practical as a really good theory - Ludwig Boltzmann
When your only tool is a hammer, every problem looks like a nail - Abraham Maslow
  Reply With Quote
Old 21st January 2013, 12:51 AM   #3
Jay is offline Jay  Indonesia
diyAudio Member
 
Join Date: Feb 2003
Location: Jakarta
PA is about robustness. There are many different conditions for "PA". So we are talking about sufficient protection for the likely abuse in differing PA environments.

So the question is whether to use internal protection or additional external protection. With internal protection, I don't know about the PA environment here, but for common situations where we the owner do not have control of the amp, it is not sufficient at all.

But for "light" PA, make sure you add sufficient input capacitance, output RC and LR.
  Reply With Quote
Old 22nd January 2013, 04:31 PM   #4
JMFahey is offline JMFahey  Argentina
diyAudio Member
 
JMFahey's Avatar
 
Join Date: Mar 2009
Location: Buenos Aires - Argentina
I don't like parallelling Power Amps, at all.
Bad practice, even if suggested in the datasheet.
And "to get more power" you must go down in impedance, usually meaning speakers in parallel.
That said, I would build many individual single LM3886 50/60W PCBs, each driving its own speaker (and a couple Piezo Tweeters).
Cheap and reliable.
You may feed 2 or 3 of them from a single (properly sized) power supply, of course.
Same PSU you would have used for the doubled or tripled version, by the way.
  Reply With Quote
Old 23rd January 2013, 09:59 AM   #5
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally Posted by Jay View Post
PA is about robustness.................
Quote:
Originally Posted by JMFahey View Post
.......................... I would build many individual single LM3886 50/60W PCBs, each driving its own speaker (and a couple Piezo Tweeters).
Cheap and reliable.....................
I have said this many times before.

Lose one speaker or one amplifier and the show goes on.
Lose two and the show just about goes on.

But one BIG amp and a set of speakers in series/parallel and the show stops if one fails.
__________________
regards Andrew T.
  Reply With Quote
Old 23rd January 2013, 11:59 AM   #6
expert in tautology
diyAudio Member
 
bear's Avatar
 
Join Date: Apr 2002
Location: New York State USA
Wait.

The OP wants to "play music outdoors"?

Off a CD at a party?
Or a PA for his band?

If you want a PA for a band, what sreten said is the most important thing - make 100% certain you can not turn up the volume and *clip the amps*. Then sure, ur amp will work out fine.

Typically, 100-150watts is insufficient for a PA. Why? Because the PA has to produce undistorted (vocals) sound at a level equal or greater than that of the guitar/keyboard amps that are "X" watts, but at distortion levels of 10% or greater. The power/headroom required to do that properly is on the order of 10x the sum of all the amps on the stage. (forget about putting drums into the PA, then you need even more)

Band PA/SR really needs some extra thought and design.
__________________
_-_-bear
http://www.bearlabs.com -- Btw, I don't actually know anything, FYI -- [...2SJ74 Toshiba bogus asian parts - beware! ]
  Reply With Quote
Old 24th January 2013, 01:14 PM   #7
diyAudio Member
 
Join Date: Aug 2004
Location: Argentina
thanks guys, more clear now
  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
Problem with parallel LM3886 (PA 100) mnturner Chip Amps 89 25th May 2010 04:05 AM
Pyle PA Amps-Any Good? kelticwizard Instruments and Amps 0 15th January 2007 02:35 AM
LM3886 PA/Live Sound designs? takodabut Chip Amps 2 21st December 2006 05:42 PM
Someone know a good fullrange PA design ? darkm4n Full Range 40 16th January 2004 09:15 PM


New To Site? Need Help?

All times are GMT. The time now is 06:35 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