What resistor and potentiometer values for GC shunt volume control? - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 19th September 2007, 08:27 PM   #1
diyAudio Member
 
Join Date: Oct 2005
Default What resistor and potentiometer values for GC shunt volume control?

I have a modified dac-ah (8xTDA1543 with passive I/V) connected to a Peter Daniels LM3875 kit.

I believe the input impedance of the amp is about 18.5Kohm (?). The passive I/V resistor in the dac is 150R. I get about 1Vpp from the dac.

I have been using a PEC 1meg pot with 39Kohm resistor in fake law configuration. The sound is great, but the pot doesn't track evenly at the start of the rotation and the volume comes in very quickly so it is impossible to get a satisfactory channel match at low listening levels.

I picked this attenuator to work with my previous single TDA1543 dac which also had passive I/V but with a much higher output impedance. Now I have the 8 dacs running in parallel, I feel ready to change to a different attenuator configuration which gives better low level channel matching and lower input impedance.

What would be the best passive attenuator configuration to try? I am tempted to go with a 10Kohm series resistor and log pot in shunt position, but have no idea what value of pot would be best.

Or would another setup be preferable?

Any advice would be much appreciated :-)
  Reply With Quote
Old 20th September 2007, 04:02 AM   #2
Leolabs is offline Leolabs  Malaysia
diyAudio Member
 
Leolabs's Avatar
 
Join Date: Dec 2004
Location: Bukit Mertajam
Send a message via MSN to Leolabs
http://www.shine7.com/audio/gainclone.htm
  Reply With Quote
Old 20th September 2007, 08:23 AM   #3
diyAudio Member
 
Join Date: Oct 2005
Excellent - thanks Leolabs :-)
  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
Shunt or serie volume control maxpou Solid State 32 6th December 2008 06:07 AM
Shunted volume: pot & resistor values Sanaka Everything Else 20 13th February 2008 03:07 AM
Volume Control (potentiometer) SergeDufour Parts 1 6th December 2006 10:56 PM
Digital potentiometer as volume control Bricolo Solid State 15 29th January 2003 09:32 PM


New To Site? Need Help?

All times are GMT. The time now is 05:07 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