PGA2311 pre-amp static discharge problem - Page 2 - diyAudio
Go Back   Home > Forums > Design & Build > Parts

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, 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 25th March 2013, 05:21 AM   #11
diyAudio Member
 
Join Date: Jul 2003
Location: Dona paula, Goa
Transformer is the only component that is connected to the mains. If you isolate it properly, there should be no shock hazard.

Gajanan Phadte
  Reply With Quote
Old 25th March 2013, 08:25 AM   #12
marce is offline marce  United Kingdom
diyAudio Member
 
Join Date: Jun 2007
Location: Blackburn, Lancs
No, the advice you are giving is against the rules of this site. It is a dangerous practice, ALL metal parts must be fastened to the protective earth connection.
  Reply With Quote
Old 28th March 2013, 06:07 AM   #13
diyAudio Member
 
Join Date: Jul 2003
Location: Dona paula, Goa
Looks like you have not used an amp with 2pin mains connector.

Be careful, it is dangerous to use them.
  Reply With Quote
Old 28th March 2013, 09:16 AM   #14
Cobra2 is offline Cobra2  Norway
DIY !
diyAudio Member
 
Cobra2's Avatar
 
Join Date: Apr 2002
Location: Stavanger, Norway
Send a message via Skype™ to Cobra2
Quote:
Originally Posted by gmphadte View Post
Looks like you have not used an amp with 2pin mains connector.

Be careful, it is dangerous to use them.
Yes, we know...just do not tell anyone

Had the same s***-kit, same trouble, and to top it: Logitech Squeezebox-code interfered...

Arne K
__________________
Don't believe everything you think...
  Reply With Quote
Old 28th March 2013, 10:49 PM   #15
marce is offline marce  United Kingdom
diyAudio Member
 
Join Date: Jun 2007
Location: Blackburn, Lancs
Got an Audiolab 8000A Circa 1994
I'm meant building or moding to remove the PE from equipement that has it.
  Reply With Quote
Old 29th March 2013, 12:01 AM   #16
dmills is offline dmills  United Kingdom
diyAudio Member
 
Join Date: Aug 2008
Location: High Wycombe
Quote:
Originally Posted by gmphadte View Post
Looks like you have not used an amp with 2pin mains connector.
Class II is perfectly safe, BUT IS NOT SOMETHING A DIYER CAN USUALLY BE RELIED UPON TO PULL OFF SAFELY....

There is nothing inherently wrong with a class II (double insulated) amp, but the engineering to ensure safety in the event of a fault is subtle enough that this site quite rightly takes a 'if you have to ask' view on the subject and bans discussion of building class II mains power supplies. Class I is very much easier to make safe, and if implemented sanely does not cause ground loops.

The circuit does however generally seem to be missing anything much in the way of ESD protection and anti RFI measures, AND WHERE IS THE DECOUPLING??!
Those 100uf cans are fine at audio frequency, but the digital side will be running more then a little bit faster that, a scattering of 100n ceramics around the +-5V rails really would not go amis.

Check continuity between the mains earth and the PCB mounting screw in the lower left of the picture (That seems to be the PCB earth terminal), and check that the logic board earth is connected correctly.

73, Dan.
  Reply With Quote
Old 3rd April 2013, 03:09 PM   #17
diyAudio Member
 
activexp's Avatar
 
Join Date: Jul 2009
Send a message via ICQ to activexp Send a message via AIM to activexp Send a message via MSN to activexp Send a message via Yahoo to activexp
Quote:
Originally Posted by dmills View Post

Check continuity between the mains earth and the PCB mounting screw in the lower left of the picture (That seems to be the PCB earth terminal), and check that the logic board earth is connected correctly.

73, Dan.
Continuity between mains earth, PCB mounting, logic board and control knob checks out fine. Any other ideas?

Regards,
Steve
  Reply With Quote
Old 3rd April 2013, 03:52 PM   #18
rsavas is offline rsavas  Canada
diyAudio Member
 
Join Date: Aug 2012
Location: Ontario
As was said previously, anodizing is an insulator, if you want to make the chassis completely at earth ground you have to add some bite through the oxide into the aluminum itself, use some lock washers!!
  Reply With Quote
Old 3rd April 2013, 06:25 PM   #19
diyAudio Member
 
activexp's Avatar
 
Join Date: Jul 2009
Send a message via ICQ to activexp Send a message via AIM to activexp Send a message via MSN to activexp Send a message via Yahoo to activexp
Quote:
Originally Posted by rsavas View Post
As was said previously, anodizing is an insulator, if you want to make the chassis completely at earth ground you have to add some bite through the oxide into the aluminium itself, use some lock washers!!

Continuity is good. The mounting screws go through drilled holes and are in direct contact with raw aluminium but I'll give lock washers a try.

Regards,
Steve
  Reply With Quote
Old 6th April 2013, 11:41 AM   #20
diyAudio Member
 
activexp's Avatar
 
Join Date: Jul 2009
Send a message via ICQ to activexp Send a message via AIM to activexp Send a message via MSN to activexp Send a message via Yahoo to activexp
I always ground my DIY projects to mains earth for safety reasons. Never had any problems with hum loops. The problem with the pre-amp is sensitivity to static discharge which is quite random, sadly not solved by making the recommended changes to the grounding arrangement.
  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
static 'hissing' noise problem hakentt Car Audio 20 14th April 2014 07:22 PM
TDA2616, PGA2311 soundbar noise problem child1 Chip Amps 2 18th January 2013 10:30 AM
Help with LM3886 + Crystal PGA2311 pre-amp kit! Hubba Chip Amps 11 15th August 2011 06:23 PM
Cracking/Static in Pre-Amp TheVille Solid State 2 17th April 2009 08:42 PM
Static Discharge Issues for Zen Amp McJerry Pass Labs 5 26th August 2001 01:41 PM


New To Site? Need Help?

All times are GMT. The time now is 11:42 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