Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Pass Labs This forum is dedicated to Pass Labs discussion.

B1 pre earth safety question (newbie)
B1 pre earth safety question (newbie)
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 15th June 2009, 10:22 PM   #1
scorpio1 is offline scorpio1  Belgium
diyAudio Member
Join Date: Nov 2008
Default B1 pre earth safety question (newbie)

Sorry for the possibly stupid question showing the very limited knowledge I have. I tried to search the 1750+ long thread on the B1 to find an answer, but no luck.

I'm putting together a B1 from using the board purchased at passdiy. It will be a 2 boxes system with the power supply in one and the pre itself in the other. I plan to have the box containing the power supply grounded to earth.

My question is, do I need for safety to run a chassis ground connection from the second box to the one containing the power supply, or is OK to leave it like that?

Thanks for your help,
  Reply With Quote
Old 16th June 2009, 12:04 AM   #2
Nelson Pass is offline Nelson Pass  United States
The one and only
Nelson Pass's Avatar
Join Date: Mar 2001
B1 pre earth safety question (newbie)
The general answer is yes, you should arrange for an earth ground
connection for any component which might conceivably get connected
to the AC line.

There are switching supplies out there (wall wart types and such) which
are safety approved and which often don't provide an earth ground at
all. Presumably their output is safe not being earth grounded.

If you are building your own supply, you should hard ground it's
chassis to the Earth terminal of the AC power socket, provide minimal
value fusing on both AC lines (live and neutral), and also ground the
secondary supply ground which is also probably your chassis ground on
the chassis which is separate from the supply.

Often grounding the secondary supply ground results in ground loops,
and it is common practice to ground this through a diode bridge or
power thermistor in an effort to provide some signal isolation while
still having a path to ground. The bridge or thermistor should be
able to withstand without damage, those current which will be get
through the fuses.

  Reply With Quote
Old 16th June 2009, 05:30 PM   #3
scorpio1 is offline scorpio1  Belgium
diyAudio Member
Join Date: Nov 2008
Thanks so much for taking the time to answer my question Nelson, very much appreciated.

I will do some search to implement the bridge or thermistor solution you suggested before trying to test the pre-amp in my system,

Best regards,
  Reply With Quote


B1 pre earth safety question (newbie)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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
connecting audio ground to Safety Earth AndrewT Power Supplies 41 30th May 2011 11:50 AM
Building a class II PSU (double insulated, no safety earth) mr.duck Power Supplies 12 12th January 2009 02:18 PM
Please help with safety earth using wood enclosure A Sanchez Chip Amps 7 27th June 2008 09:25 AM
one safety question audio_moksha Tubes / Valves 3 6th February 2008 07:31 PM
first I earth the chassis for safety but why do I need to conect it to my ground... frank2395 Pass Labs 4 20th May 2005 01:15 PM

New To Site? Need Help?

All times are GMT. The time now is 03:06 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio