Go Back   Home > Forums > >

Group Buys Members group buys

DIY TDA1541A PCB "D3"
DIY TDA1541A PCB "D3"
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
Old 15th November 2019, 02:50 AM   #391
markos4553 is offline markos4553  United States
diyAudio Member
 
Join Date: Mar 2010
Location: Central, MN
Hi Ben,


I really appreciate the help!


On startup Both AOR and AOL vary a bit with AOL after a little while able to be zeroed and adjusted back and forth over the 0V point. AOR settles around 90mV with one TDA and 40mV with a different known working TDA.


I realize this is very difficult to troubleshoot over the internet and I can take any measurement if needed. I can also start desoldering and replacing if necessary.


Thanks,


Mark K.
  Reply With Quote
Old 15th November 2019, 02:52 AM   #392
markos4553 is offline markos4553  United States
diyAudio Member
 
Join Date: Mar 2010
Location: Central, MN
Voltage measurements are being taken across G and S of AOL&AOR.
  Reply With Quote
Old 15th November 2019, 02:56 AM   #393
ggetzoff is offline ggetzoff  United States
diyAudio Member
 
ggetzoff's Avatar
 
Join Date: Nov 2004
Location: Southwest
Quote:
Originally Posted by markos4553 View Post
Greg where was your ground reference for the voltage measurement?


Mark K.
Mark, on the chip socket GND.

Where is everyone else measuring?

Greg
__________________
Airline Pilot-If it's not Boeing I'm not going.
Aleph J, F4, DCB1, VHEX +, USSA-5, BA-3 Pre, DCG3, USSPA, Transcendent Sound Masterpiece (sold) TDA1541A D3, RH84, D3 Build guide
  Reply With Quote
Old 15th November 2019, 02:58 AM   #394
ggetzoff is offline ggetzoff  United States
diyAudio Member
 
ggetzoff's Avatar
 
Join Date: Nov 2004
Location: Southwest
I measured on the socket GND for the -5, +5, and -15.
__________________
Airline Pilot-If it's not Boeing I'm not going.
Aleph J, F4, DCB1, VHEX +, USSA-5, BA-3 Pre, DCG3, USSPA, Transcendent Sound Masterpiece (sold) TDA1541A D3, RH84, D3 Build guide
  Reply With Quote
Old 15th November 2019, 03:04 AM   #395
markos4553 is offline markos4553  United States
diyAudio Member
 
Join Date: Mar 2010
Location: Central, MN
Quote:
Originally Posted by ggetzoff View Post
I measured on the socket GND for the -5, +5, and -15.

Ok me too! Just curious.


Mark K.
  Reply With Quote
Old 15th November 2019, 03:15 AM   #396
Ben Mah is online now Ben Mah  Canada
diyAudio Member
 
Join Date: May 2012
Location: Vancouver
DIY TDA1541A PCB "D3"
Hi Mark,

The Output bias circuit is very simple with only a few parts. If 5V is being delivered and the TDA chip is outputting 2mA, then something in the circuit is not working properly. It could be solder connections, or pot not working properly, or C56 not working properly.

You have already checked the 2K resistor. You also had measured 0.3V across the IV resistor when the 2K resistor was out of the circuit so the IV resistor and parallel capacitor are OK, and the TDA chip is sending out the 2mA current.

You can desolder the pot and test it out of circuit. You can desolder C56 and try the circuit without it. The circuit will work without the C56. Or if you have a capacitor tester, you can test it when you have the pot off the board.

Also check the solder joints again.

Ben
  Reply With Quote
Old 15th November 2019, 03:47 AM   #397
markos4553 is offline markos4553  United States
diyAudio Member
 
Join Date: Mar 2010
Location: Central, MN
I desoldered C56 and it checked out at 1uf and I've desoldered and checked TR1 and it checks out at 1K.


I've desoldered and replaced C58 even though it tested good at 154pF. I've now tested everything in the Bias circuit so it must be somewhere else.


Mark K.
  Reply With Quote
Old 15th November 2019, 03:59 AM   #398
Ben Mah is online now Ben Mah  Canada
diyAudio Member
 
Join Date: May 2012
Location: Vancouver
DIY TDA1541A PCB "D3"
Did you check TR1 to make sure that the resistance varies from 0 to 1K when you adjust it?
  Reply With Quote
Old 15th November 2019, 04:11 AM   #399
markos4553 is offline markos4553  United States
diyAudio Member
 
Join Date: Mar 2010
Location: Central, MN
Hi Ben,


I connected one test lead to the center pin and the other test lead to the outer pins and both responded correctly. 0ohms to 1Kohms.


Thanks,


Mark K.
  Reply With Quote
Old 15th November 2019, 04:22 AM   #400
Ben Mah is online now Ben Mah  Canada
diyAudio Member
 
Join Date: May 2012
Location: Vancouver
DIY TDA1541A PCB "D3"
Well, it could be that the pot is hard to adjust. 90mV amounts to .090V/150R = .0006A and 40mV amounts to .040V/150R = .000267A.

When you adjust the pot, does the voltage across the IV resistor change from negative to positive or vice versa?
  Reply With Quote

Reply


DIY TDA1541A PCB "D3"Hide this!Advertise here!
Thread Tools

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
"Reference" TDA1541A DAC with I2S-BUS architecture dvb projekt Group Buys 1613 24th April 2019 01:56 AM
TDA1541A "piggybacking" on analog metric pcb? Mayday Digital Source 43 4th June 2012 08:55 AM
For Sale : dvb-projekt "Reference" TDA1541A DAC PCBs Thesoundmen Swap Meet 1 27th July 2011 03:21 AM
A real DAC Philips TDA1541A "Double Crown"? dbhh Digital Source 17 7th May 2004 05:15 AM


New To Site? Need Help?

All times are GMT. The time now is 12:13 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki