Balanced quasi-floating output - diyAudio
Go Back   Home > Forums > Design & Build > Parts

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

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
Old 29th December 2004, 11:47 AM   #1
xocoatl is offline xocoatl  Poland
diyAudio Member
Join Date: Apr 2003
Location: Kraków, PL
Question Balanced quasi-floating output

Hi guys!
I've just found intereting output circuit on Douglas Self's page about balancing . And I think about using it in my preamp. But as I look on it , as I is drawn below, I'am not sure if it'd work like it should. Which do yuo think OPAMPs (or are these finite/low gain amps) inputs are + / - ?

Click the image to open in full size.

I searched google and this forum with no success.
  Reply With Quote
Old 30th December 2004, 05:15 AM   #2
Stocker is offline Stocker  United States
diyAudio Member
Join Date: Dec 2003
Location: Austin
reminds me a bit of the front end of a citation 16 schematic.... At the least it's unusual, at best you might like the way it sounds!
Jesus loves you.
  Reply With Quote
Old 30th December 2004, 01:18 PM   #3
Previously: Kuei Yang Wang
Join Date: Nov 2002
Default Re: Balanced quasi-floating output


Originally posted by xocoatl
I've just found intereting output circuit
Actually, the circuit is not entierly complete. A complete one is here:

Click the image to open in full size.

In that case it is best to generate the balanced drive by using a further Op-Amp in inverting unity gain configuration. The same circuit can be adapted to Single ended input, here an example from a circuit used in a Behring Digital X-Over:

Click the image to open in full size.

That one is of limited value for actual use, as the gain is below unity, but it illustrates the requiorements for unbalancing the resistors with single ended drive.

The first circuit shown together with added inverting Op-Amp on a chip is readily available from TI/Burr Brown as DRV134 and from Analog/SSM as SSM2142 all integrated onto a single chip.

Personally experience however suggests that despite the extra cost a high quality line output transformer (Stevens & Billington TX410LO for example) is a better choice, if sound quality is of concern.

  Reply With Quote


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
quasi-complementary output Vlad Pass Labs 4 13th April 2010 12:07 PM
Floating current source in cascoded output stage rtarbell Pass Labs 0 7th April 2006 01:46 AM
Revised quasi pnp output amp Easyamp Solid State 0 18th December 2003 01:30 AM

New To Site? Need Help?

All times are GMT. The time now is 10:25 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