passive unbalancing differential signal - diyAudio
Go Back   Home > Forums > Source & Line > Digital Line Level

Digital Line Level DACs, Digital Crossovers, Equalizers, 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
Reply
 
Thread Tools Search this Thread
Old 29th March 2015, 03:07 PM   #1
donovas is offline donovas  South Korea
diyAudio Member
 
Join Date: Jun 2014
Default passive unbalancing differential signal

hello. can i unbalance +/- signal from dac with no transformer, no opamp?

i'm saying just capacitors from +/- to RCA +/- and pulldown resistor to ground. possible?
  Reply With Quote
Old 29th March 2015, 03:09 PM   #2
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Simply a switch to connect - signal to ground for unbalanced signal.
  Reply With Quote
Old 29th March 2015, 03:57 PM   #3
donovas is offline donovas  South Korea
diyAudio Member
 
Join Date: Jun 2014
so no cap needed for - signal?
  Reply With Quote
Old 29th March 2015, 04:00 PM   #4
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
The output of a DAC probably isn't balanced but biphase. A balanced output you can convert to unbalanced just by grounding one side. A biphase output you convert to unbalanced by totally ignoring one side.
  Reply With Quote
Old 29th March 2015, 04:35 PM   #5
diyAudio Member
 
Join Date: Jun 2007
Quote:
Originally Posted by DF96 View Post
The output of a DAC probably isn't balanced but biphase. A balanced output you can convert to unbalanced just by grounding one side. A biphase output you convert to unbalanced by totally ignoring one side.
This may not be the whole story.
Please measure whether the signal is riding on top of a DC voltage (perhaps a couple of volts). This needs to be eliminated either with a cap or sending both legs to a transformer so the DC (+ and -) will cancel.
  Reply With Quote
Old 29th March 2015, 04:52 PM   #6
donovas is offline donovas  South Korea
diyAudio Member
 
Join Date: Jun 2014
yes, both output have dc offset. 0.3v or so.
  Reply With Quote
Old 29th March 2015, 05:05 PM   #7
diyAudio Member
 
Join Date: Jun 2007
Quote:
Originally Posted by donovas View Post
yes, both output have dc offset. 0.3v or so.
That does not make sense, I may be missing something.
We are trying to see if signal is balanced (one side inverted relative to the other). Or is it bi-phasic ie. one side riding on (+) DC and the other side riding on (-) DC. In my limited experience, the DC would be much larger than 0.3V
  Reply With Quote
Old 29th March 2015, 06:14 PM   #8
donovas is offline donovas  South Korea
diyAudio Member
 
Join Date: Jun 2014
they are balance, signal polarity +/-. but class a opamp i/v, so dc offset.

custom breadboard dac.
  Reply With Quote
Old 30th March 2015, 09:34 AM   #9
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
Probably biphase AC, but both riding on approximately equal DC biases. If so, put a coupling capacitor from one output to the RCA inner. Ground RCA outer (at the appropriate circuit point). Put a high value resistor across the RCA to act as a ground leak.

Why anyone should go to the trouble of making/buying a balanced DAC then running it unbalanced is a question for another day.
  Reply With Quote
Old 30th March 2015, 10:39 AM   #10
donovas is offline donovas  South Korea
diyAudio Member
 
Join Date: Jun 2014
thank you.

as for the big question, sound still benefit from unbalancing than using one phase.
  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
Tube conversion of differential to single ended signal audiowize Tubes / Valves 5 8th August 2013 08:19 PM
passive differential input stage Bernhard Solid State 1 29th January 2013 03:12 PM
Floating Differential Signal Zaaphod Analog Line Level 34 27th September 2011 09:36 PM
Volume control of a differential signal berni8k Digital Line Level 20 26th August 2009 09:43 AM
Creating a differential signal from a single-ended signal for bridged amps Peter Daniel Chip Amps 45 8th November 2004 12:47 PM


New To Site? Need Help?

All times are GMT. The time now is 12:28 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.
Copyright 1999-2015 diyAudio

Content Relevant URLs by vBSEO 3.3.2