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

Chip Amps Amplifiers based on integrated circuits

Mains problems
Mains problems
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 4th April 2004, 01:55 AM   #1
jeff mai is offline jeff mai  Australia
diyAudio Member
 
jeff mai's Avatar
 
Join Date: Aug 2002
Location: Melbourne
Default Mains problems

I recently built a dead-bug style gain-clone. The sound is quite acceptable. One problem, however, is high susceptibility to garbage on the mains supply.

While listening I frequently notice ticks and pops. Today, it decided to blow several slow-blow fuses at power up until I turned off the overhead fan in the toilet. A hair dryer makes the toroid vibrate severely.

Anything to be done about this?
  Reply With Quote
Old 4th April 2004, 04:19 AM   #2
cocolino is offline cocolino  Germany
diyAudio Member
 
cocolino's Avatar
 
Join Date: May 2002
Location: Bavaria (south of veal sausage equator)
Quote:
While listening I frequently notice ticks and pops. Today, it decided to blow several slow-blow fuses at power up until I turned off the overhead fan in the toilet.
Jeff,

Motors can cause garbage on the mains supply and maybe Yours cause the ticks and pops - You could try a mains filter with the motor (or/and the amp.) .

Why the motor should/could be responsible to blow fuses in Your amp I have no idea. I don`t think the motor has something to do with this and the fuses blew incidentally while the motor was running. Maybe it is turn on surge problem (a turn on surge don`t necessarily blow fuses each time at power on) caused from the toroids (quite common) and You need sort of a soft start circuit .

Something like this:

http://home.swipnet.se/~w-50719/hifi...ida_sst01.html


Quote:
A hair dryer makes the toroid vibrate severely.
The dryer very likely cause DC-voltage on the AC-line and is the cause that Your toroid vibrates.
Check this thread and use the simple DC blocking circuit for line application - this should cure it:

http://www.diyvideo.com/forums/showt...080&highlight=
__________________
Christoph
STEAL the BEST - INVENT the REST
  Reply With Quote
Old 4th April 2004, 07:46 AM   #3
jeff mai is offline jeff mai  Australia
diyAudio Member
 
jeff mai's Avatar
 
Join Date: Aug 2002
Location: Melbourne
Quote:
Originally posted by cocolino
I don`t think the motor has something to do with this and the fuses blew incidentally while the motor was running. Maybe it is turn on surge problem (a turn on surge don`t necessarily blow fuses each time at power on) caused from the toroids (quite common) and You need sort of a soft start circuit .
No, I think the fuse blowing in the amp has to do with the motor running. I've had the amp for six weeks, switching it on and off several times / day and did not blow the fuse once. Today, the fuse blew twice during amplifier power up while the fan motor was running. After turning off the motor, it powered up fine with the same fuse value.

The ticks and pops I've noticed are only heard in one channel and are at times very frequent (1 / sec though not cyclical) and don't seem to be related to anything switching inside the house. I had the TV running earlier and could "see" the some of the louder ones as white lines momentarily appearing on the screen as I heard them through the speaker.

This is an old house and likely has really poor electrical service / wiring. I'm renting though...
  Reply With Quote
Old 4th April 2004, 08:24 AM   #4
Nuuk is offline Nuuk  United Kingdom
diyAudio Member
 
Nuuk's Avatar
 
Join Date: Feb 2003
Location: Somerset, SW England
It sounds to me as though you need to get your house wiring checked over. How old is the wiring?
__________________
The truth need not be veiled, for it veils itself from the eyes of the ignorant.
  Reply With Quote
Old 17th April 2004, 06:56 AM   #5
jeff mai is offline jeff mai  Australia
diyAudio Member
 
jeff mai's Avatar
 
Join Date: Aug 2002
Location: Melbourne
I have no idea how old the house wiring is. Probably old.

I have wired a 0.1uf 275VAC X2 cap across line and neutral. It seems to have helped with some of the ticking sounds, but the larger pops still sail through to the speakers.

What else might I do?
  Reply With Quote
Old 17th April 2004, 08:25 AM   #6
Nuuk is offline Nuuk  United Kingdom
diyAudio Member
 
Nuuk's Avatar
 
Join Date: Feb 2003
Location: Somerset, SW England
Quote:
What else might I do?
Put safety and commonsense ahead of hi-fi and have your house rewired!
__________________
The truth need not be veiled, for it veils itself from the eyes of the ignorant.
  Reply With Quote
Old 17th April 2004, 08:49 AM   #7
jeff mai is offline jeff mai  Australia
diyAudio Member
 
jeff mai's Avatar
 
Join Date: Aug 2002
Location: Melbourne
Quote:
Originally posted by Nuuk
Put safety and commonsense ahead of hi-fi and have your house rewired!
I'm very unclear as to what has convinced you that the wiring in my residence is unsafe. Beyond reciting the symptoms I described, perhaps you might educate me by describing the reason behind this concern? I'm not likely to initiate rewiring a house unless I know what problem I'm solving.

In any event, my only recourse to faulty wiring is relocation: I rent.

Can someone else offer a suggestion? I'm certain others have had problems with mains-borne noise entering their chip amps. It is interesting that these noises do not seem to afflict my valve amp when plugged in to the same mains socket.
  Reply With Quote
Old 17th April 2004, 10:28 PM   #8
xato is offline xato  Spain
diyAudio Member
 
Join Date: Apr 2004
Location: la xara
why donīt you try with a diferential trafo(like in tv psu)in the input ac?
  Reply With Quote
Old 18th April 2004, 01:30 AM   #9
jackinnj is offline jackinnj  United States
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Mains problems
Quote:
Originally posted by jeff mai
I have no idea how old the house wiring is. Probably old.

I have wired a 0.1uf 275VAC X2 cap across line and neutral. It seems to have helped with some of the ticking sounds, but the larger pops still sail through to the speakers.

What else might I do?
go to the product descriptor on Nat Semi's website -- you might try one of the RFI cures -- putting a capacitor across the IN+ and IN- pins of the LM3875.

there are quite a few line filter descriptions on the web-- bifiliar windings etc. i have posted the schematic of one recommended for ham radio gear somewhere on DIYAUDIO but damned if I can find it
  Reply With Quote

Reply


Mains problemsHide 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
MAINS... simple, old style amplifier, plugged into mains electrical outlet (110) destroyer X Solid State 2 15th June 2008 02:31 PM
Mains power problems Vivek Everything Else 2 9th April 2005 05:04 PM
Mains Switch Problems Angel-Baby Solid State 4 23rd March 2004 06:42 PM


New To Site? Need Help?

All times are GMT. The time now is 07:49 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki