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

TRIPATH EB-TA0104 revisited
TRIPATH EB-TA0104 revisited
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
Thread Tools Search this Thread
Old 30th August 2009, 11:48 AM   #1
QED047 is offline QED047  United Kingdom
diyAudio Member
Join Date: May 2009
Default TRIPATH EB-TA0104 revisited

Following on from my Paralleled Class A with Class D experiment, I decided to dig out an old TA0104 evaluation board and compare the performance. Something about the output from the parallel amp reminded me of the TRIPATH... the "spread spectrum" and relatively high switching frequencies... could it even be the trick behind so-called "Class T"?

I shelved the evaluation board almost 10 years to the day, but instantly remembered the bodge-up they did for the 12V lower gate drive supply when I got it on the bench again. This bit was a switching reg. originally fronted by a 51V Zener drop - to allow it to run between the main 0V and -V supply. A transistor follower was used to help the dissipation, but they still hung a label on the board warning against higher supplies than 70V. This time I got out the desolder pump and cleared all nonsense away. I've built a separate transformer supply for the +5 and +12 along with startup sequencing and muting. While I'm at it I've also got it a rack-case and its own toroid plus capacitor bank. Now it's running comfortably at +/-80V

There is an uncanny similarity in the output waveforms - definately some kind of self-oscillating hysteretic control is involved. But I get a more pleasurable sound from my experimental parallel amp - probably due to the minimalistic (naive?) single-ended front end consisting of nothing more than a couple of transistors and two hot resistors.

Peeking under the TRIPATH module there's obviously a lot more going on than I've got on the parallel amp but I'm still rather pleased with my DIY effort.
Attached Images
File Type: jpg VN12.jpg (62.8 KB, 192 views)
File Type: jpg DSC01550.JPG (843.6 KB, 180 views)
File Type: jpg DSC01551.jpg (435.2 KB, 182 views)
  Reply With Quote
Old 2nd September 2009, 01:56 PM   #2
QED047 is offline QED047  United Kingdom
diyAudio Member
Join Date: May 2009
Still need to fit a 2U front panel and lid but all the wiring is complete. Having a logic level mute is handy - so I've added a 3.5mm jack to the back panel - into which I can plug a USB/jack lead. This allows the amp to be automatically muted if I'm using it with my PC. This is almost essential as the M-audio 2496 sound-card I use creates a *ridiculous* amount of hash when the PC shuts down.

> One fright I gave myself remains unexplained though - with the amp running and connected to speakers and sound-card I pulled out one of the phono inputs and a very loud screech came out of that channel instantly accompanied by a plume of smoke from the TRIPATH board

The amp shutdown pretty fast as the -ve 80V rail fuse blew. The smoke came from a 33R snubber resistor on the channel I was disconnecting. Nothing seems to have taken damage though - after replacing the fuse and plugging everything back in after a careful inspection it all works OK again. I have to confess that I'm too chicken to try pulling the phono plug again - not while I don't understand what happened.... anyone got any ideas?
Attached Images
File Type: jpg TRIP1.jpg (50.9 KB, 156 views)
  Reply With Quote
Old 2nd September 2009, 06:33 PM   #3
theAnonymous1 is offline theAnonymous1  United States
diyAudio Member
theAnonymous1's Avatar
Join Date: Feb 2004
Location: Anonymityville
I had a TC2001/TP2350 board do this to me once. It was connected to a car audio SMPS. There was a very loud "whine" when I powered it up and the output zobels started to smoke.

It turned out it was from the two sections not being grounded properly.

BTW, I have a deep hatred for these damn Tripath modules. I think I've blown something like 6 TA0104A modules and one TDA2500 from various experiments. They are not very robust and seem to die if you so much as glance at them the wrong way.

I have one TA0104A module left if anyone is interested. I don't ever plan on putting it in a powered board, I know what will happen to it if I do.
  Reply With Quote
Old 2nd September 2009, 10:01 PM   #4
QED047 is offline QED047  United Kingdom
diyAudio Member
Join Date: May 2009
I'm thinking that the reason mine smoked was feedback - switching noise getting into the freshly opened input. The event seemed to coincide with the phono plug just disconnecting the shroud (inner still making contact). Just to be sure I've added a 200K resistor and a 100pF bypass between the input and ground. Still to chicken to deliberately pull a plug though.

TBH, I'll probably shelve this amp again but it's been interesting digging it out for a review. I just noticed serial no. 008 in silver ink on the board. I guess this makes it a fairly early model!?!
  Reply With Quote
Old 3rd September 2009, 10:36 AM   #5
luka is offline luka  Slovenia
diyAudio Member
luka's Avatar
Join Date: Sep 2005
Location: in Slovenia :)
TRIPATH EB-TA0104 revisited
Board that I have now, has no S/N, and what you are saying you are putting +/-80v to it? is that ok with board and ta104?
  Reply With Quote


TRIPATH EB-TA0104 revisitedHide 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
Rebuilt my old Tripath TA0104-based ampifier jahonen Class D 15 23rd February 2009 04:52 PM
WTB: Tripath TA0104 Module laugoo Swap Meet 1 21st July 2008 04:48 AM
Tripath TA0104 Eval Board Problem - Help! laugoo Class D 0 2nd June 2008 07:06 AM
FS: 3 Tripath TA0104 eval boards and PS parts guyv Swap Meet 4 25th December 2007 08:34 AM
Tripath TA0104 board - wanna buy blmn Swap Meet 2 9th March 2006 09:23 PM

New To Site? Need Help?

All times are GMT. The time now is 01:53 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio