
Home  Forums  Rules  Articles  diyAudio Store  Blogs  Gallery  Wiki  Register  Donations  FAQ  Calendar  Search  Today's Posts  Mark Forums Read  Search 
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 

Thread Tools  Search this Thread 
21st December 2012, 10:13 AM  #21 
diyAudio Member
Join Date: May 2008

I do not understand your post exactly though i suppose you speak about the Vbe multiplier.
If so, for more current into the output stage: increase Rb2 Refering to:Page 12 of LME49811 datasheet VBIAS= VBE(1+Rb2/Rb1) Last edited by bobodioulasso; 21st December 2012 at 10:26 AM. 
21st December 2012, 12:55 PM  #22 
diyAudio Member
Join Date: Oct 2009
Location: Brisbane, Australia

I really think you need to spend more time reading datasheets. the LME chips have a VERY well documented amplifier application note that answers all (or at least many) of your questions.

24th December 2012, 08:42 PM  #23  
diyAudio Member
Join Date: Aug 2012

Quote:
so in the above case it can give about 2Amps of output if increasing the Rb2 so what is the maximum bias current that I can achieve with this? what are the limitations? like I want to bias till 2.5 amps can I do that? what is the max limit on what factor it is dependent? 

24th December 2012, 09:00 PM  #24  
diyAudio Member
Join Date: Aug 2012

Quote:
so using 4 pairs of output devices is enough for safe operation? and no thermal runaway? but I still have a question that do we need an external driver to feed the base current or Gate current to the output stages? since according to you each pair requires about 2.5 amps so for all 8 devices its 20 amps of continuous current! the big question is that how considering that this amp would deliver 100W of class A power then what should be the psu rating? 2KVa? preferably safe... but can you tell me what driver to use to give 2.5 amps for each output device? 

24th December 2012, 09:22 PM  #25 
diyAudio Member
Join Date: Aug 2012

but technically class A amplifier pow is calculated as I x I x R example in your case 2.5 bias current which is continuous and peak its considered as 5 amps and for 5 x 5 x 8 ohms 200W peak and in RMS its 141W RMS
but my prob is what should be the gate current for each output device example toshiba 2sj201 output mosfet? what driver to use and how many stages to be used for the above power? 
Thread Tools  Search this Thread 


Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
diyAB "Honey Badger" Class AB Power AmpPair  Ana  The diyAudio Store  4  24th November 2016 01:11 PM 
FS: New boxed pair of B&C ME10 Horns, $15 for the pair!  matevana  Swap Meet  0  17th July 2012 06:02 PM 
F/S 1 x pair 3.3uf VCAP OIMP and 1 x pair Mundorf silver/oil 0.68uf  qusp  Swap Meet  4  31st October 2011 04:18 PM 
Driver transistors for 2SC5200&1943  ttan98  Solid State  43  11th May 2008 02:52 AM 
2sa1302/2sc5200 Power Expected?  zox2003  Solid State  38  27th March 2005 09:57 AM 
New To Site?  Need Help? 