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 13th December 2003, 08:25 PM   #11
diyAudio Member
 
JensRasmussen's Avatar
 
Join Date: Jul 2002
Location: Denmark - Jutland
Send a message via ICQ to JensRasmussen Send a message via MSN to JensRasmussen
Default State space in idear

Hi,

Nice work,

Is it based on a state space regulator?

How about some real life results?

\Jens
  Reply With Quote
Old 13th December 2003, 08:29 PM   #12
diyAudio Member
 
Bernhard's Avatar
 
Join Date: Apr 2002
Location: Munich
Default Re: State space in idear

Quote:
Originally posted by JensRasmussen
Hi,

Nice work,

Is it based on a state space regulator?

\Jens

a please what
  Reply With Quote
Old 13th December 2003, 08:40 PM   #13
Account Disabled
 
Join Date: Apr 2003
Location: US
Default Re: no mercy distortion killer circuit

Quote:
Originally posted by Bernhard
Or does anybody have an idea how I do that ?

but does it make tea for me?

  Reply With Quote
Old 13th December 2003, 08:48 PM   #14
Netlist is offline Netlist  Belgium
diyAudio Moderator Emeritus
 
Netlist's Avatar
 
Join Date: Jan 2003
Did you use current feedback opamps?

/Hugo
  Reply With Quote
Old 13th December 2003, 08:57 PM   #15
diyAudio Member
 
Bernhard's Avatar
 
Join Date: Apr 2002
Location: Munich
Quote:
Originally posted by Netlist
Did you use current feedback opamps?

/Hugo
No, everything is NE5532 for simplicity.
  Reply With Quote
Old 13th December 2003, 08:58 PM   #16
diyAudio Member
 
johnferrier's Avatar
 
Join Date: Sep 2003
Location: WA
Bernhard,

I had thought that the cross-coupling topology would eliminate most distortion too.

See example on last page of the AD8610 datasheet:
http://www.analog.com/UploadedFiles/...D8610_20_c.pdf

This seems very similar to your circuit. There may be other cross-coupled diagrams that are closer to yours.

As I looked more carefully, I found that distortion at/caused by the input circuitry doesn't cancel because it looks like the signal. And at the outputs (across R8) the feedback isn't an identical mirror. On the left the feedback is from the output of X3, and on the right, the feedback is from the inverted output of X4. (This would all probably work okay with ideal components.) In my mind, these two aspects make it not work perfectly. Also, others have indicated this cross-coupled circuitry only cancels even order distortion.

Analog Devices and Texas Instruments actually make single ended to differential out chips that they claim lowers second harmonic distortion (no cancels).


JF
  Reply With Quote
Old 13th December 2003, 09:14 PM   #17
diyAudio Member
 
Bernhard's Avatar
 
Join Date: Apr 2002
Location: Munich
Quote:
Originally posted by johnferrier

As I looked more carefully, I found that distortion at/caused by the input circuitry doesn't cancel because it looks like the signal. And at the outputs (across R8) the feedback isn't an identical mirror. On the left the feedback is from the output of X3, and on the right, the feedback is from the inverted output of X4. (This would all probably work okay with ideal components.) In my mind, these two aspects make it not work perfectly. Also, others have indicated this cross-coupled circuitry only cancels even order distortion.

Analog Devices and Texas Instruments actually make single ended to differential out chips that they claim lowers second harmonic distortion (no cancels).


JF

John,

As I wrote, there is no feedback from the output stage to X3, just to simulate worst case conditions.
X3 needs his own feedback to be a voltage follower gain 1x.
Also this is not cross-coupled.
It is only from left side to right side, not vice versa. A one way ticket.


The function of the circuit is clearly defined, there is no question about how much coupling has to be.

R13/R14 are equal and gain of X4 is 2x gain of X3.

If the output stage is inside the feedback loop of X3, there is nothing left to worry about.

X5 could be a high end op amp like opa627 or it could be left out if X4 is a differential amp.

I also wrote this is a functional model and further improvements are possible.

Anyway it works perfect on the sim already.
  Reply With Quote
Old 13th December 2003, 09:21 PM   #18
diyAudio Member
 
Join Date: Aug 2003
Location: Prague,Czech Republic
This amp will have nonsymetrical slew rate and will be oscilate, 'cos gates of mosfets are driven from outputs of opamps without any serial resistor.
  Reply With Quote
Old 13th December 2003, 09:21 PM   #19
diyAudio Member
 
johnferrier's Avatar
 
Join Date: Sep 2003
Location: WA
But some of the distortion at/caused by the inputs of X3+ and X5- will look like signal.


JF
  Reply With Quote
Old 13th December 2003, 09:24 PM   #20
diyAudio Member
 
Bernhard's Avatar
 
Join Date: Apr 2002
Location: Munich
Quote:
Originally posted by Upupa Epops
This amp will have nonsymetrical slew rate and will be oscilate, 'cos gates of mosfets are driven from outputs of opamps without any serial resistor.
Yes, I forgot the gate resistors, sorry
  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
Simple Killer Amp - Circuit analysis Eva Solid State 148 21st February 2006 12:32 PM


New To Site? Need Help?

All times are GMT. The time now is 11:14 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