Comparing LME49810, 49830 and 49811 - Page 52 - 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 30th November 2012, 03:43 AM   #511
diyAudio Member
 
panson_hk's Avatar
 
Join Date: Aug 2005
Blog Entries: 10
It seems that many Toshiba 2SC/2SA audio transistors are replaced by new models. Are they new P/N, but same die? Most vendors focus on DC/DC type applications than linear.
  Reply With Quote
Old 6th February 2013, 04:33 PM   #512
diyAudio Member
 
Join Date: Aug 2012
can LME49810 be used for class A? as the previous posts say that LME49830 itself is biased in A/B. I agree 811 works in class A but how about 810?
  Reply With Quote
Old 6th February 2013, 04:50 PM   #513
catalin is offline catalin  Romania
diyAudio Member
 
Join Date: Jun 2007
Quote:
Originally Posted by rhythmsandy View Post
can LME49810 be used for class A? as the previous posts say that LME49830 itself is biased in A/B. I agree 811 works in class A but how about 810?
Both chips has the vas biased in class A .811 has the output direct from the vas stage.The 49810 added an emitter follower to provide a higher current at the output .So the 810 has the vas in class A like 811 but also an simple class A/B emitter follower stage .
__________________
"please try to listen to some music through the amplifier instead. Life is so short ..."
  Reply With Quote
Old 7th February 2013, 03:16 AM   #514
diyAudio Member
 
Join Date: Aug 2012
Quote:
Originally Posted by catalin View Post
Both chips has the vas biased in class A .811 has the output direct from the vas stage.The 49810 added an emitter follower to provide a higher current at the output .So the 810 has the vas in class A like 811 but also an simple class A/B emitter follower stage .
so the 810 vas might be in class A but the emitter follower at its output would not run in class A if biased at the output stage isnt it?
  Reply With Quote
Old 7th February 2013, 06:52 AM   #515
catalin is offline catalin  Romania
diyAudio Member
 
Join Date: Jun 2007
Here is a similar example,hope that it helps ,To have triple output stage at 811 you must add 6 transistors .To have triple on 810 you must add only 4 transistors because 2 are already in it .
Attached Images
File Type: jpg ggg.JPG (85.9 KB, 540 views)
__________________
"please try to listen to some music through the amplifier instead. Life is so short ..."

Last edited by catalin; 7th February 2013 at 06:54 AM.
  Reply With Quote
Old 7th February 2013, 07:21 AM   #516
diyAudio Member
 
Join Date: Aug 2012
Quote:
Originally Posted by catalin View Post
Here is a similar example,hope that it helps ,To have triple output stage at 811 you must add 6 transistors .To have triple on 810 you must add only 4 transistors because 2 are already in it .
can you attach the spice file i would like to simulate few things..
  Reply With Quote
Old 7th February 2013, 09:31 AM   #517
catalin is offline catalin  Romania
diyAudio Member
 
Join Date: Jun 2007
Spice thing of what ?I don't have a spice file for the TI LME's
__________________
"please try to listen to some music through the amplifier instead. Life is so short ..."
  Reply With Quote
Old 7th February 2013, 10:41 PM   #518
diyAudio Member
 
audioman54's Avatar
 
Join Date: Jun 2008
Hi everyone at DIY,

Sorry I have not posted for quite some time but I just got a notice in my email about a comment on this thread and thought I could shed a little light on the questions posted here...

The LME49810 was designed for high power amplifiers for the music industry and a class AB stage was added to its output stage to bring the output current up to 50ma (60max on data sheet) to be able to achieve 2KW with a single Darlington output stage. It also has a pure Baker Clamp which is only slightly different than a similar circuit implemented in the LME49811 and LM4702.

The LME49811 is a class A internal implementation but it only has 7ma of output current. It also has a "Bob Pease" improvement to the layout of its input stage to improve low level thermal performance. We did this when we split the stereo LM4702 in half to create the LME49811, that I specified.

I have been listening to the LME49811's used in a mono block amplifier design, very similar to the circuit in app note AN-1490 for the stereo LM4702, at home and here in our sound room at TI Santa Clara for over 5 years now. With 50VDC rails that amplifier has no trouble driving our Wilson Watt Puppy model 7's at work. You can see from the graph in AN-1490 (for the very similar stereo LM4702) that this amplifier design achieves 0.0005% THD+N. Actually my LME49811 amplifier measures even better than that.


Best TI Audio Regards,

Mark Audioman54
  Reply With Quote
Old 7th February 2013, 11:04 PM   #519
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Quote:
Originally Posted by audioman54 View Post
Best TI Audio Regards,
Ya did that "reverse Joad family commute" in which so many Californians now find themselves. Welcome back!

Click the image to open in full size.
  Reply With Quote
Old 8th February 2013, 03:18 AM   #520
diyAudio Member
 
Join Date: Aug 2012
Quote:
Originally Posted by audioman54 View Post
Hi everyone at DIY,

Sorry I have not posted for quite some time but I just got a notice in my email about a comment on this thread and thought I could shed a little light on the questions posted here...

The LME49810 was designed for high power amplifiers for the music industry and a class AB stage was added to its output stage to bring the output current up to 50ma (60max on data sheet) to be able to achieve 2KW with a single Darlington output stage. It also has a pure Baker Clamp which is only slightly different than a similar circuit implemented in the LME49811 and LM4702.

The LME49811 is a class A internal implementation but it only has 7ma of output current. It also has a "Bob Pease" improvement to the layout of its input stage to improve low level thermal performance. We did this when we split the stereo LM4702 in half to create the LME49811, that I specified.

I have been listening to the LME49811's used in a mono block amplifier design, very similar to the circuit in app note AN-1490 for the stereo LM4702, at home and here in our sound room at TI Santa Clara for over 5 years now. With 50VDC rails that amplifier has no trouble driving our Wilson Watt Puppy model 7's at work. You can see from the graph in AN-1490 (for the very similar stereo LM4702) that this amplifier design achieves 0.0005% THD+N. Actually my LME49811 amplifier measures even better than that.


Best TI Audio Regards,

Mark Audioman54

The only problem I see is the slew which is 15v/us and that is relatively low when compared with 810. Is it possible to get more slew out of 811? like 50v/us.

I am fixing with 811 as its more pure. Like I said If its possible to get more slew then its fine is that internally fixed?

I do agree that we dont require more slew in general but on selling front it makes big different.. and to be precise the slam will be great...
  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
LME 49811 Project? jaya000 Chip Amps 21 28th August 2013 12:31 AM
My differential input 49830 Phil Olson Solid State 6 7th May 2012 12:38 AM
49830 tweaking traw Chip Amps 0 3rd June 2009 04:35 AM
National LME 49811 satanx Chip Amps 2 8th May 2008 11:29 PM
3886x3 vs 49830 Phil Olson Chip Amps 10 26th March 2008 06:59 PM


New To Site? Need Help?

All times are GMT. The time now is 06:51 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