Popping in my DAC - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, 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 6th August 2004, 11:00 PM   #1
diyAudio Member
 
5th element's Avatar
 
Join Date: Oct 2002
Location: England
Default Popping in my DAC

Ive posted about this some time back in the thread I created when I first posted about the DAC.

Now the popping whilst diminished still persists.

I dont think this is anything to do with the digital side of things and am more concerned with the power supply.

OK well ive got LM317 and 337 performing regulation at about 16volts for the IV stage and output filter. This is not the problem because when the DAC output is muted there is silence.

Ive got LM340 @5v performing regulation for the DAC PCM1798 and an LM1086 @3.3v for the digital circuitry in the DAC and the DIR1703.

When I was first trouble shooting with the DAC I disconnected the DC powersupply to the main board several times and once connected the negative rail to the positive input on the board.
The caps in the power supply were fully charged, thus 4700uf @25 volts powered its way to everything. This didnt seem to affect anything performance wise, still getting the correct voltages everywhere, but the LM1086 got waaay hotter then it did previously as far as i am aware.

When I get the popping its quite loud and occurs mostly when music starts to play (ie there is sudden demand, albeit quite small, for current) and can either occur in the left or right channel but mainly in both at the same time. The popping can occur whenever it really wants to, but is worse when loud music is playing. This is not loud as in the volume control is turned up obviously, but when a loud passage plays.

Anyone any ideas?

Are those regs suited to this application?

Matt
__________________
What the hell are you screamin' for? Every five minutes there's a bomb or somethin'! I'm leavin! bzzzz!
  Reply With Quote
Old 8th August 2004, 02:15 AM   #2
Banned
 
Join Date: Mar 2003
Location: Lisbon, Portugal
Why not change the regs?
They are cheap.
If you are suspicious of the LM1086, start there.
  Reply With Quote
Old 8th August 2004, 10:20 PM   #3
diyAudio Member
 
5th element's Avatar
 
Join Date: Oct 2002
Location: England
I was going to anyway when I next make an order to a place that sells them! But I was going to ask if these are suitable for the application in case they were not, so I could replace them with ones more suited.
__________________
What the hell are you screamin' for? Every five minutes there's a bomb or somethin'! I'm leavin! bzzzz!
  Reply With Quote
Old 9th August 2004, 06:41 PM   #4
diyAudio Member
 
5th element's Avatar
 
Join Date: Oct 2002
Location: England
With that in mind are there any particular fixed 5 and 3.3v regs that are specially suited to DACS and digital circuitry?
__________________
What the hell are you screamin' for? Every five minutes there's a bomb or somethin'! I'm leavin! bzzzz!
  Reply With Quote
Old 9th August 2004, 11:57 PM   #5
guzzler is offline guzzler  Scotland
diyAudio Member
 
Join Date: Feb 2003
Location: Scotland
most 5V and all 3.3V regulators are really for digital circuits. For best performance, look for the LDO types which can be stabalised with a very small input/output capacitance. Personally, I use the REG102 series from TI

g
  Reply With Quote
Old 10th August 2004, 01:04 AM   #6
diyAudio Member
 
Join Date: May 2002
Location: Plano , TX
Send a message via AIM to jewilson
Check out Walt Jung regulators, these are very low noise and great transient responce. There are number of people copying these designs so PCB are out their. Also http://www.audioxpress.com/ sales the older designs of this PCB and it work very good.

http://home.comcast.net/~walt-jung/w...7s-20PDFs.html
__________________
Jim W.
  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
amp popping fligti91 Parts 0 10th November 2007 11:06 PM
Popping from Forte 6 Arroyo Pass Labs 0 15th July 2007 05:55 PM
Midrange keeps on popping pjaneiro Multi-Way 20 1st January 2007 01:07 AM
ICE popping up all over! mp006ltk Class D 0 20th October 2006 08:37 PM
Fuse popping Rodeodave Power Supplies 6 23rd September 2005 05:48 PM


New To Site? Need Help?

All times are GMT. The time now is 06:50 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