Problem with 80W mosfet amplifier - help me please - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 13th September 2011, 07:10 PM   #1
diyAudio Member
 
Join Date: Sep 2011
Location: Malaysia
Post Problem with 80W mosfet amplifier - help me please

Hi

Can anyone help me with this circuit??
Click the image to open in full size.

and here's the PDF version of it :
888.pdf - 4shared.com - document sharing - download

I bought this circuit as a kit but it has some hiss and noise(when no music is played) that I want to remove them from my speaker

here's the original version of this circuit :
Click the image to open in full size.

and its site :
Simple Circuits MosFet Amplifier IRF9530 IRF530 | DIY Audio Electronic Surround Sound Home Theater System Techno News

can anyone help me??
  Reply With Quote
Old 13th September 2011, 07:34 PM   #2
NMOS is offline NMOS  Germany
diyAudio Member
 
NMOS's Avatar
 
Join Date: Dec 2010
Location: Frankfurt
in my opinion poor design

IRF 9630 / 630 are not really symetrical


use QUASI NMOS 300/500 with N Channel output devices

no hiss and HIgH END Sound
  Reply With Quote
Old 13th September 2011, 07:50 PM   #3
diyAudio Member
 
Join Date: Sep 2011
Location: Malaysia
Hi NMOS

So all these noise and hiss is because of output Mosfets ??? are you sure????
Can you tell me the exact part name of this "QUASI NMOS 300/500"???
  Reply With Quote
Old 13th September 2011, 10:05 PM   #4
diyAudio Member
 
Join Date: Aug 2011
Location: London
Can anyone help me to remove these noises?
  Reply With Quote
Old 14th September 2011, 04:44 AM   #5
diyAudio Member
 
Join Date: Aug 2011
Location: London
anyone?
  Reply With Quote
Old 15th September 2011, 05:47 PM   #6
diyAudio Member
 
east electronics's Avatar
 
Join Date: Jan 2006
Location: Athens GREECE
define if its a noise or a hiss .... hiss and noise are diferent things

hiss might be produced from a low quality IC also from poor filtering on the ic ( c1 c2 ) you might try some other alternative IC than the tl

first of all you need to try your amp with input shorted to ground to make sure that his or noise doesnt come from the source or the wiring

if noise is heard like 50 HZ you have a ground loop issue
__________________
SERVICE ΕΝΙΣΧΥΤΩΝ ΚΑΙ ΙΑΠΩΝΙΚΩΝ ΜΗΧΑΝΗΜΑΤΩΝ ΗΧΟΥ www.eastelectronics.gr
  Reply With Quote
Old 15th September 2011, 06:12 PM   #7
diyAudio Member
 
digits's Avatar
 
Join Date: Apr 2011
I would start with a 100nf cap from pin 4 to 7 on the IC, right on the chip.
  Reply With Quote
Old 15th September 2011, 08:11 PM   #8
BrianVG is offline BrianVG  Belgium
diyAudio Member
 
Join Date: Jun 2010
Location: Louvain
Also, you can add a 'Boucherot network'

Quote:
A boucherot cell (or Zobel network) is an electronic filter, used in audio amplifiers to damp high frequency oscillations that might occur in the absence of loads at high frequencies. Named after Paul Boucherot a boucherot cell typically consists of a resistor and capacitor in series, that is usually placed across a load, for stability.
It is placed at the output of the amp and then you connect your speaker.
Also make sure that your ground-cables are as short as possible. They can work like as an antenna and pick up noise/occur oscillation.
__________________
FET fanatic
  Reply With Quote
Old 15th September 2011, 08:47 PM   #9
wahab is offline wahab  Algeria
diyAudio Member
 
Join Date: Nov 2009
Location: algeria/france
An experimental design from ELEKTOR whose typography is instantly recognizable..
The site doesnt seems to credit this review , though...
  Reply With Quote
Old 17th September 2011, 06:58 PM   #10
diyAudio Member
 
Join Date: Sep 2011
Location: Malaysia
thank you all for your suggestions

At first I thought this hiss sound is producing from my amp (when I open this thread) but when I checked my computer's sound card with my headphone I realized that this hiss is from my computer
I ask a few friends and they said that I should change my sound card.
I wanna know that is there any way so I can remove this hiss from my computer's output????
My main board is GIGABYTE GA-EP43_DS3L and I'm using its onboard sound card.
If there's no way to remove this hiss from this sound card, can anyone introduce me a good sound card ??(without any hiss or hum or any noise)
  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
80W Hybrid Audio Amplifier! radio Solid State 42 20th July 2014 10:48 AM
Maplin 100W mosfet amplifier - power supply problem HBrunt Solid State 32 3rd December 2013 07:11 AM
JLH 80w mosfet power amplifier - modifying it Kevinbd Solid State 116 6th October 2012 01:38 PM
One Channel of JLH 80w Mosfet Louder than other foxyb Solid State 2 12th October 2004 01:14 AM
Linsley-Hood 80W mosfet amp Spartacus Solid State 10 16th December 2003 04:55 AM


New To Site? Need Help?

All times are GMT. The time now is 11:59 PM.


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