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

audible hum with two Sure TA2024 boards on same source
audible hum with two Sure TA2024 boards on same source
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 December 2016, 02:05 PM   #11
doctormord is offline doctormord  Germany
diyAudio Member
 
doctormord's Avatar
 
Join Date: Oct 2007
Quote:
Originally Posted by turk 182 View Post
and i wish people would stop using low impedance source outputs like Ipods and there ilk as a source device across amp inputs that are designed as line level and wonder why they are having problems or thinking it sounds good.

and what makes you think the pre out's on the receiver are isolated?
What's the point here? Apple products, Iphone4+ have pretty descent output DACs. If the amplifier can't deal with this, it's not the sources fault.
  Reply With Quote
Old 29th December 2016, 02:07 PM   #12
HumbleDeer is offline HumbleDeer  Belgium
diyAudio Member
 
HumbleDeer's Avatar
 
Join Date: Oct 2016
Location: In Flanders Fields Gender: Female
I think that every one of those small chip amps has a "sync" line. If you put the correct resistor between the two chips, you can have them natively sync their clocks.

The same thing is done with the cheap TPA-based amps on Ebay. Those amps also have such sync line. Sadly, they don't use it very often or appropriately

This amp has 2 chips which is similar to 2 seperate chips, somewhat.

https://youtu.be/16k4goWRT4o
  Reply With Quote
Old 31st December 2016, 11:36 PM   #13
Hybrid fourdoor is offline Hybrid fourdoor  United States
diyAudio Member
 
Hybrid fourdoor's Avatar
 
Join Date: May 2003
Location: Ft. Worth, TX
Ya I had watched that video actually before I bought the boards, but I couldn't find anything about it for this chip.

Anyways, I ended up using 2 separate supplies and the buzz/hum is completely gone. So it has to do with sharing the power.

How can I strip "AC" out of the power? put an inductor inline, or would a capacitor across the red and black be better?
  Reply With Quote
Old 31st December 2016, 11:40 PM   #14
djoffe is offline djoffe  United States
diyAudio Member
 
Join Date: Oct 2008
You need both. Now, there's probably already some bypass capacitance on the board, so the inductance by itself would be a good start.
__________________
www.akitika.com Featuring the GT-102 Power Amp and PR-101 Preamp kits
www.updatemydynaco.com Featuring upgrades for classic Dynaco Solid State Equipment
  Reply With Quote
Old 1st January 2017, 09:31 AM   #15
Grib is offline Grib  France
diyAudio Member
 
Join Date: Dec 2016
Location: west coast (France)
Quote:
Originally Posted by Hybrid fourdoor View Post
Anyways, I ended up using 2 separate supplies and the buzz/hum is completely gone. So it has to do with sharing the power.
Did you try that ?
Quote:
Originally Posted by Grib View Post
You should probably try to split the ground of the PSU before reaching any of the boards.
So that each board has a ground wire coming to it, and no board act as a ground splitting point.
  Reply With Quote
Old 5th January 2017, 02:54 AM   #16
Hybrid fourdoor is offline Hybrid fourdoor  United States
diyAudio Member
 
Hybrid fourdoor's Avatar
 
Join Date: May 2003
Location: Ft. Worth, TX
I used a DC power Y cable that had 2x 2.1mm connections. I tried that from one supply and the pulsing sound was only audible if you put your ear right on the driver. But it was there none the less.

I stepped up to an 18.5V laptop supply and gave each amplifier module its own LM7815 15V regulator. With this, the high pitched pulsing was completely gone and only a faint <normal> hiss could be heard.

So I solved the problem.

Click the image to open in full size.
  Reply With Quote
Old 5th January 2017, 03:47 AM   #17
Hybrid fourdoor is offline Hybrid fourdoor  United States
diyAudio Member
 
Hybrid fourdoor's Avatar
 
Join Date: May 2003
Location: Ft. Worth, TX
Oh and if you were wondering I checked the amperage of the board before going the regulator route. At idle and low volume it used 65mA (0.065A). At comfortable volumes it used 71mA. This was with both channels driven into an 8 ohm load.
  Reply With Quote

Reply


audible hum with two Sure TA2024 boards on same sourceHide 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
audible hum.trafo or groundloop? ishiru Digital Line Level 5 26th November 2014 09:52 AM
Ta2020 ta2024 tk2050 Hiss hissing noise hum !@solve xslavic Class D 0 22nd June 2014 02:20 PM
Locating hum source Rundmaus Tubes / Valves 31 29th March 2013 10:06 PM
Preamp / buffer suggestions for TA2020 / TA2024 boards lossfound Class D 11 29th January 2012 10:35 AM


New To Site? Need Help?

All times are GMT. The time now is 10:06 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki