Quuestion about signal dissection - 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 17th May 2006, 03:40 AM   #1
diyAudio Member
 
Join Date: Sep 2005
Default Quuestion about signal dissection

Question:

I have two identicle amplifiers. I want to take a signal and "chop it in half"; that is to say that I want all of the positive part of the signal to go to one amplifier, and all of the negative part of the signal to go to the other amplifier. Their outputs will be summed up to drive a simple speaker.

My idea here is to design an output stage using all NPN or N-channel devices for better device matching without using the quasi-complementary approach. I know that tube amps use phase splitters or transformers with center taps, but I'm trying to get a completely DC coupled amp from first to last stage.

I'm in a brain lock as to how to design such a device...
  Reply With Quote
Old 17th May 2006, 05:08 AM   #2
Eva is offline Eva  Spain
diyAudio Member
 
Eva's Avatar
 
Join Date: Oct 2003
Location: Near the sea
Send a message via MSN to Eva
That's not practical.
__________________
I use to feel like the small child in The Emperor's New Clothes tale
  Reply With Quote
Old 17th May 2006, 06:35 AM   #3
lndm is offline lndm  Australia
diyAudio Member
 
Join Date: Mar 2006
Location: nsw
Impractical but not impossible, but I'm not going to be the first to prove it .

If you don't want complimentary symmetry, and you don't want quasi complimentary, why not try class A?
  Reply With Quote
Old 17th May 2006, 06:46 AM   #4
diyAudio Member
 
Workhorse's Avatar
 
Join Date: Dec 2004
Quote:
Originally posted by Eva
That's not practical.

No EVA, Its practical in his "IMAGINATION"



Cheers,
K a n w a r
  Reply With Quote
Old 17th May 2006, 07:22 AM   #5
diyAudio Member
 
ifrythings's Avatar
 
Join Date: Oct 2005
Well I (and a few others I believe) don't understand why you'd want to do this????

A diode will clip any positive or negative singal above .6V if placed correctly... but I don't think you'd want to use that aproche.

P.S. I think all your going to do is make the worst cross-over distorstion amp ever, but if you really are bored prove me wrong.

oh, good luck keeping you wave semectrical across two amps.
  Reply With Quote
Old 17th May 2006, 08:49 AM   #6
lndm is offline lndm  Australia
diyAudio Member
 
Join Date: Mar 2006
Location: nsw
Perhaps you might read Douglas Self's words. I believe he understands distortions produced in amps, particularly along the lines of your concerns, very well indeed. He might put your concerns to rest.

http://www.dself.dsl.pipex.com/ampins/dipa/dipa.htm

If not, Nelson Pass has written about a cascode power stage which I guess you may find interesting.
  Reply With Quote
Old 17th May 2006, 09:57 AM   #7
ilimzn is offline ilimzn  Croatia
diyAudio Member
 
Join Date: Feb 2005
Location: Zagreb
Thinking about a dual coil speaker? Alternatively, you could use a transformer to 'combine' the halves, or, a circlotron circuit (one of the configurations used to do what you want with vacuum tubes).
  Reply With Quote
Old 17th May 2006, 12:16 PM   #8
diyAudio Moderator Emeritus
 
lumanauw's Avatar
 
Join Date: Oct 2002
Location: Bandung
Send a message via Yahoo to lumanauw
MusicalFidelity A1 seems to be 2 amps, one for "push" and one for "pull". But they are not all Nch though
  Reply With Quote
Old 17th May 2006, 01:01 PM   #9
diyAudio Member
 
traderbam's Avatar
 
Join Date: Jan 2002
Location: Earth
Hi Lumanauw,
Well I personnally like this kind of lateral thinking...too many ideas around here are deep inside "the box".

The perennial problem is developing a bidirectional current with uni-directional devices. The tube fraternity have solved this a million times over, so why not borrow some of their ideas?

Single-ended always works well but is wasteful of power. Circlotron has come up with some natty ways to minimize wasted power by using inductors as current sources.

If you want push-pull and don't want a transformer I know no satisfactory method that avoids p channel devices. That doesn't mean you can't invent one!
  Reply With Quote
Old 17th May 2006, 01:11 PM   #10
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Great City of Turnhout, Belgium
Blog Entries: 7
Such a design has been published in WW years ago, I think by Sandman. Used current driven diodes (to overcome the 0.6V threshold) to route the pos polarity to the pos half of the amp, and vice versa. I'll see if i can find it.

Anyway, you would still need two complete amps. The amp that is NOT amplifying the signal still has to sink the speaker current ...

Jan Didden
__________________
If you don't change your beliefs, your life will be like this forever. Is that good news? - W. S. Maugham
Check out Linear Audio!
  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
PWM signal to Audio signal possible? thx_dts71 Class D 2 11th November 2008 03:38 PM
where to get sub signal from terminatorgunit Car Audio 5 30th September 2006 10:58 PM
How do I turn an high current signal into a line level signal?? sardonx Tubes / Valves 8 27th August 2005 12:16 PM
Phono preamp dissection. Netlist Solid State 6 5th March 2005 05:55 PM
Creating a differential signal from a single-ended signal for bridged amps Peter Daniel Chip Amps 45 8th November 2004 01:47 PM


New To Site? Need Help?

All times are GMT. The time now is 11:41 PM.


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