LM4702 or LME49810 work in class A mode to drive the output stages in class A/AB - 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 23rd November 2012, 03:57 PM   #1
diyAudio Member
 
Join Date: Aug 2012
Default LM4702 or LME49810 work in class A mode to drive the output stages in class A/AB

does the chip itself works in class A?
  Reply With Quote
Old 23rd November 2012, 06:46 PM   #2
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
The output stages are Push-Pull. They will be biased to operate in ClassAB.
__________________
regards Andrew T.
  Reply With Quote
Old 23rd November 2012, 09:00 PM   #3
diyAudio Member
 
panson_hk's Avatar
 
Join Date: Aug 2005
Blog Entries: 10
I am told LME49811 output is Class A biased.
  Reply With Quote
Old 24th November 2012, 03:31 AM   #4
diyAudio Member
 
Join Date: Aug 2012
can I just replace the lme49810 with lme49811?
  Reply With Quote
Old 24th November 2012, 09:12 AM   #5
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Icc is typically around 14mA to 17mA.
Max output is stated as 9mA.
For a ClassA output this would imply an output bias of ~5mA.
Certainly ClassA is possible for the 811.

There is comment from a few years ago on the lme series from the design team.
__________________
regards Andrew T.
  Reply With Quote
Old 24th November 2012, 01:33 PM   #6
diyAudio Member
 
panson_hk's Avatar
 
Join Date: Aug 2005
Blog Entries: 10
do you have a driver for the output stage and how much output power of your design?
  Reply With Quote
Old 24th November 2012, 03:25 PM   #7
diyAudio Member
 
Join Date: Aug 2012
im thinking of going with 5200 1943 pairs..
Im considering class AB output stage in one config and
one in class A...

class A 100W ( im interested to go with scanspeak drivers for bass and mids from wavecor )
class AB 500W in 8 ohms ( I have PA subwoofers with me from Eighteen sound )

thinking of going with lme49811
  Reply With Quote
Old 25th November 2012, 02:57 AM   #8
diyAudio Member
 
panson_hk's Avatar
 
Join Date: Aug 2005
Blog Entries: 10
class a 100w! are you serious! no typo?

you need triple EF output for 500 W.
  Reply With Quote
Old 25th November 2012, 03:39 AM   #9
diyAudio Member
 
Join Date: Aug 2012
i know 100w its pretty huge... just a thought but even if 30w can serve my purpose im still fine.. like hiraga but what about the lme chips did u try them in class A?

when it comes to class AB i have seen some amp modules based on 49810 which have 5 pairs of EF and still deliver 300W in 8 ohms im looking something double to that..

the question is..
a pair of 2SA1930 and 2SC5171 can drive how many EF pairs?
  Reply With Quote
Old 25th November 2012, 06:50 AM   #10
diyAudio Member
 
panson_hk's Avatar
 
Join Date: Aug 2005
Blog Entries: 10
Yes, I did try LME498xx with Class A output stage for 20 to 30 W.

I would use A1930/C5171 as pre-driver and a pair with higher current rating as driver. Which output devices do you plane to use?

I believe you seen such 49810 amp module in eBay using C5200/A1943. Right?
  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
Contest: Linear Power Amp in a mint tin (class Aa, class AB, or class B) danielwritesbac Chip Amps 206 19th January 2013 08:52 PM
floating supply class AB will it work? is it any good? ttako Solid State 9 14th March 2010 11:48 PM
Configuring an AB class amp to work in pure A class jrme Tubes / Valves 5 23rd February 2010 06:31 PM
budget xformer for 829B pentode mode PP (class AB) ? vladn Tubes / Valves 42 12th October 2008 06:03 PM
Class A and Class AB - How Does This Work? batee Pass Labs 18 28th January 2007 11:32 AM


New To Site? Need Help?

All times are GMT. The time now is 10:19 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