Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Class D Switching Power Amplifiers and Power D/A conversion

Volume control by adjusting Voltage
Volume control by adjusting Voltage
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 8th May 2012, 07:36 PM   #1
pinobot is offline pinobot  Netherlands
diyAudio Member
 
Join Date: Oct 2005
Default Volume control by adjusting Voltage

Hi.
I'm new to this diy amplifier stuff and i'm looking into buying my first T-amp. Now it seems you can change the gain by adjusting the voltage, but why isn't that done, are there sonic disadvantages and what are they?
  Reply With Quote
Old 8th May 2012, 07:51 PM   #2
jan.didden is online now jan.didden  Europe
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: The great city of Turnhout, BE
Which voltage do you mean?
The supply voltage?

jan didden
__________________
Cable: a potential source of trouble interconnecting two other potential sources of trouble - Erik Margan
Linear Audio pubs and articles . The SilentSwitcher now at diyaudio store SilentSwitcher. Keeping in touch with SY.
  Reply With Quote
Old 8th May 2012, 08:07 PM   #3
pinobot is offline pinobot  Netherlands
diyAudio Member
 
Join Date: Oct 2005
Yes
  Reply With Quote
Old 9th May 2012, 12:58 AM   #4
wwenze is offline wwenze  Singapore
diyAudio Member
 
Join Date: Mar 2008
If gain changes with supply voltage, any noise on the supply rails will show up on the output.
  Reply With Quote
Old 9th May 2012, 04:11 AM   #5
DcibeL is offline DcibeL  Canada
diyAudio Member
 
DcibeL's Avatar
 
Join Date: May 2003
Location: Saskatchewan
To clarify the above, no, the supply voltage does not affect the gain. Feedback defines gain. Look up basic op-amp calculations to get an idea of how that works.
__________________
The power of Science compels you!
  Reply With Quote
Old 9th May 2012, 04:25 AM   #6
Capt Grogg is offline Capt Grogg  United States
diyAudio Member
 
Join Date: Aug 2009
Open loop class d amps change gain with power supply voltage change, power supply sag causes compression, noise also goes down with voltage. Lots of oportunities and yes instead of power supply rejection you get power supply injection. Used in many commercial products, including top of the line Sony multi-channel receivers
  Reply With Quote

Reply


Volume control by adjusting VoltageHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Adjusting ELS hybrids by changing the voltage ljpp Planars & Exotics 30 22nd September 2012 08:55 AM
simple question: is midpoint voltage setting for adjusting the DC Offset? Arnie75 Class D 7 29th April 2012 10:54 PM
Replacing broken volume control with digital volume control Gunawan W Solid State 19 15th December 2010 10:46 AM
Variable Voltage Volume control jkeny Power Supplies 4 10th February 2008 09:13 PM
adjusting step of remote contoled volume? sapek Parts 18 2nd January 2008 12:24 AM


New To Site? Need Help?

All times are GMT. The time now is 10:27 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki