AD843 - pre/headphone amp - 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 14th June 2010, 02:41 AM   #1
diyAudio Member
 
Join Date: Jun 2007
Default AD843 - pre/headphone amp

I've read so many good things about this opamp, yet given it is so fussy, no-one seems to have designed an amplifier based solely around it.

Has anyone seen a decent circuit using this chip?
  Reply With Quote
Old 15th June 2010, 03:51 AM   #2
gootee is offline gootee  United States
diyAudio Member
 
Join Date: Nov 2006
Location: Indiana
Blog Entries: 1
Here is the product page, at analog.com:

AD843 | 34 MHz, CBFET Fast Settling Op Amp | Military/Aerospace | Other Products | Analog Devices

Here is the datasheet:

http://www.analog.com/static/importe...eets/AD843.pdf

Maybe it's a little too "hot" for typical audio circuits, with its 10 ns rise time and 250 V/us slew rate. But I see no overriding reason that you couldn't try it, at least just to see what happens, if you pay some attention to the datasheet's circuit recommendations.
  Reply With Quote
Old 15th June 2010, 04:53 AM   #3
diyAudio Member
 
Join Date: Nov 2009
Location: Los Angeles
Quote:
Originally Posted by lordearl View Post
I've read so many good things about this opamp, yet given it is so fussy, no-one seems to have designed an amplifier based solely around it.

Has anyone seen a decent circuit using this chip?
When I did video design I looked into this amp and while it was passable for standard definition, it won't cut it for hi def. Audio wise its a little noisy and a little low on drive current. The 'fussiness' has more to do with its speed. I.E. you'd have similar concerns with any 250 V/uS amp, not the 843 in particular.

You need good grounds and stiff power supplies when dealing in high speed. It's generally 'safer' to run somewhat lower impedances with high speed amplifiers. Feedback resistors in the 1-10K range rather than 30-50K. Ground plane PCBs are preferred rather than a ground 'trunk' snaking its way around the board.

There are opamps a little better tailored for audio than the 843 but by all means try it. It certainly isn't bad but then again I AM biased towards Analog Devices products.

G
  Reply With Quote
Old 17th June 2010, 05:50 PM   #4
Nisbeth is offline Nisbeth  Denmark
diyAudio Member
 
Nisbeth's Avatar
 
Join Date: Jan 2001
Location: Denmark
Some notes: Notes on Audio Op-Amps


/U.
  Reply With Quote
Old 17th June 2010, 06:00 PM   #5
Dr_EM is offline Dr_EM  United Kingdom
diyAudio Member
 
Dr_EM's Avatar
 
Join Date: Oct 2006
Location: Swindon
Is such high bandwidth ever required for audio applications? Surely an audio specific op-amp (AD797, LM4562, even OPA2134) will give better performance in audio applications? The audio specific design of these op-amps gives them lower noise and THD whilst maintaining plenty adequate bandwidth.
  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
FS: Millett Hybrid headphone amp / pre-amp and Tube power amplifier BuzzerBro Swap Meet 7 22nd June 2010 08:51 PM
HLLY HIGH END DMK-IV USB DAC Headphone AMP Pre-AMP hllyelec Vendor's Bazaar 19 4th January 2010 01:10 AM
Silicon Chip July06 / EPE Feb08 Studio Series Pre-Amp with remote and Headphone Amp pgamble Headphone Systems 6 8th November 2009 09:50 AM
NE5532 as a pre amp for a Szekeres headphone amp zebra100 Headphone Systems 2 1st July 2009 09:15 AM
need a PS for a pre, DAC, and headphone amp fishski13 Power Supplies 6 12th February 2009 06:59 PM


New To Site? Need Help?

All times are GMT. The time now is 07:29 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