High Power Amplifier with LM391-100 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 25th October 2011, 03:32 PM   #1
diyAudio Member
 
Join Date: Dec 2010
Default High Power Amplifier with LM391-100

Any practical Hi Power low distortion amplifier circuit with IRFP240 & IRFP9240 MOSFET.
  Reply With Quote
Old 25th October 2011, 05:17 PM   #2
farjon is offline farjon  Brazil
diyAudio Member
 
farjon's Avatar
 
Join Date: Jul 2003
Location: Rio de Janeiro, RJ
Lm391 N100

I know only this, with BJTs:

Power Amplifier 35W with LM391

It appears to be obsolete:

LM391 - Audio Power Driver [Discontinued]
  Reply With Quote
Old 28th December 2011, 05:38 AM   #3
diyAudio Member
 
Join Date: Dec 2011
Location: MAGOYLA WEST OF ATTIKA
Default LM391N-100

Merry christmas
Hi i am nick from Greece and i am new to forum
I have an amp 2x 100w at 8Ω with LM391N-100....bd 139-bd140 as driver and the output transistor is MJ15003 and MJ15004 by Harries ..2 transformer 2x33voltAC secondary eatch ...2x10.000 mf 63 volt sic safco capacitor for eatch amp
And the sound Exelend very easy and Detail
Regards
  Reply With Quote
Old 28th December 2011, 06:41 AM   #4
diyAudio Member
 
Join Date: Apr 2010
Location: Coffs Harbour, on the east coast
Wow! 100W/8R with BD139/40 drivers and 46V rails?
There must be some big transformers and special drivers there.
__________________
regards
  Reply With Quote
Old 28th December 2011, 07:16 AM   #5
diyAudio Member
 
Join Date: Dec 2011
Location: MAGOYLA WEST OF ATTIKA
Default LM391N-100

LM391 - Audio Power Driver [Discontinued]

buy from ebay or........ from BG electronics hear BG-Electronics LM391N-100, LM391N-80, LM391N80, LM391N100
The input impedance to my amp is 10k -gain and bandwidth is selectable for this IC
Important
Give very good source and preamp (descrete) whith low output resistance ......and
This amp drive my loudspeaker JMLAB FOCAL PS5.1 Point Source at 4Ω
  Reply With Quote
Old 28th December 2011, 07:32 AM   #6
diyAudio Member
 
Join Date: Dec 2011
Location: MAGOYLA WEST OF ATTIKA
Hi Ian
The transformer is 300va eatch and 4 bridges semicron 25A ..2 per amp
this amp drive my loudspeake JMLAB Focal PS5.1 point source at 4Ω
I bought some lm391n-100 from BG Electronics about a year ago
  Reply With Quote
Old 31st December 2011, 07:12 AM   #7
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
With no thermal tracking on the bias, amplifiers using the LM391 frequently blew up, even the designs with class B output stages.

I keep a few LM391 around to repair the old PA amplifiers used in 70V systems that used this chip.

I would never use it in a new design.
__________________
Candidates for the Darwin Award should not read this author.
  Reply With Quote
Old 31st December 2011, 11:40 AM   #8
jaycee is offline jaycee  United Kingdom
diyAudio Member
 
Join Date: Apr 2004
Location: Norwich, UK
I was thinking that myself - where's the thermal tracking? With a CFP output stage as shown by Sam and in the datasheets it might be acceptable. I guess you could also wire up some external sensing diodes between pins 7 and 6.

The equivalent schematic shows that it's nothing special - a pretty standard current-sourced LTP, with current mirror loading, and a cascode VAS. You'd get better results with discrete parts.
  Reply With Quote
Old 1st January 2012, 06:22 PM   #9
diyAudio Member
 
Join Date: Dec 2011
Location: MAGOYLA WEST OF ATTIKA
The amplifier is my possession since 1988 with excellent results
is about the same with (lm391pdf ) at page 11- and no sam circuit
The resistors Reb-Reb' -R1-R'1and Rf1 -Rf2-Cf want calculation acording the pdf
The voltage rail +/- is important for calculation to ( Reb-Reb' and to R1-R1')
Entry capacitor are 10mf mkp direct the pin 2
and input impedance is 10 Kohm- bias current is about 30- 40ma
at the pin 14 I think I have a capacitor 10mf
  Reply With Quote
Old 2nd January 2012, 08:11 AM   #10
diyAudio Member
 
east electronics's Avatar
 
Join Date: Jan 2006
Location: Athens GREECE
i presume that the amplifier is red and blue pcb and made by a company called ""hobby kits"" electronics .... Actually a very good Greek kit company that executed properly suggestions and schematics from National and/or other companies .

the good thing is that this company actually used the best available parts at the time ( nothing exotic ) just very good quality ....

Company is long time ago gone since prizes was 3 times up from any other available kit at the market , at the time .

As about the amp it shelf was a terrible amplifier ( with today's standards ) with probably terrible performance figures ....expect your amplifier to have mos of the capacitors dead as we speak..

things that went wrong with this amplifier is basically that the performance was based on the performance of the IC ...the bandwidth and speed was limited and for the people that didn't know enough the biggest mistake was the wiring between the board and the output transistors the use of flat cable that was included inside the kit ( that actually originated from PSU technology ) was the number one reason for oscillations and instability ...

other than the above it was just bellow average

kind regards sakis
__________________
SERVICE ΕΝΙΣΧΥΤΩΝ ΚΑΙ ΙΑΠΩΝΙΚΩΝ ΜΗΧΑΝΗΜΑΤΩΝ ΗΧΟΥ www.eastelectronics.gr
  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
High Voltage BjT's for Pre-driver stages of High Power Amplifier - Overview tiefbassuebertr Solid State 38 30th May 2011 07:37 AM
Opto Power Amplifier - 100% NPN lineup Solid State 33 1st May 2011 10:49 AM
Lm391 N100 east electronics Solid State 4 27th April 2009 05:40 PM
Kenwood KM-207 - 200 Watts x 2/8ohm - power amplifier - $100 + shipping zobsky Swap Meet 0 29th March 2009 10:00 PM
HIGH Power Sub amplifier? Killjoy99 Solid State 31 18th September 2006 01:54 AM


New To Site? Need Help?

All times are GMT. The time now is 03:58 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