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

8V on outputs
8V on outputs
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 11th September 2005, 08:54 AM   #1
dome406 is offline dome406  United Kingdom
diyAudio Member
Join Date: Mar 2004
Location: uk
Exclamation 8V on outputs

I have just finished making a gainclone which sound good at the moment however buzzes/hisses so need to look at grounding etc. The dc offset with noload and inputs shorted is 25mv and 7mv.

However I was measuring the dc offset or something like that on my old amp (a panasonic thing which has an integrated tuner cassette deck and balancer it is combined 30W) that I am using at the moment for my speakers and it gives out 8V on its output !!! I am measiring with no load and inputs shorted. It doesn't change when I turn the volume up or down or unshort the input.

Is this the way I am measuring it, or is this true with some amps, I don' want to damage my speakers but I will be using my gainclone soon so it won't matter too much until it explodes .

  Reply With Quote
Old 11th September 2005, 09:15 AM   #2
pinkmouse is offline pinkmouse  Europe
diyAudio Moderator
pinkmouse's Avatar
Join Date: Apr 2002
Location: Rotherham, England
8V on outputs
If it's a very old amp, it may well be single ended. In that case, the output electro may well have gone leaky with age and is passing dc from the biasing.
Rick: Oh Cliff / Sometimes it must be difficult not to feel as if / You really are a cliff / when fascists keep trying to push you over it! / Are they the lemmings / Or are you, Cliff? / Or are you Cliff?
  Reply With Quote
Old 11th September 2005, 09:19 AM   #3
dome406 is offline dome406  United Kingdom
diyAudio Member
Join Date: Mar 2004
Location: uk
It is very old it may be over 10years old because I have had it for 6 years and my uncle had it in his garage , is it damaging my speakers because that is the last thing I want
  Reply With Quote
Old 11th September 2005, 03:16 PM   #4
DigitalJunkie is offline DigitalJunkie  United States
diyAudio Member
Join Date: Apr 2003
Location: Portland,Oregon
Send a message via AIM to DigitalJunkie
It could damage your speakers,if the caps are really leaky,but you'd probably notice the speaker cones moving in or out when you turn the amp on?
They probably aren't leaky enough to cause major damage right away,but it's something you want to check out

Try measuring the voltage across the output with a couple 8ohm resistors in place of the speakers as a 'dummy load'.
There should be very little (if any) voltage across the output with a load on it.
  Reply With Quote


8V on outputsHide 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
finding pre-amp outputs chuck55 Solid State 7 26th September 2008 03:12 AM
Balanced outputs used as inverting & Non-inverting preamplier outputs gni Solid State 4 19th September 2008 03:25 AM
Edcor outputs? kegger Tubes / Valves 4 3rd February 2007 04:35 PM
how low is 'low DC' on SOZ outputs? psarin Pass Labs 8 8th March 2002 01:39 PM

New To Site? Need Help?

All times are GMT. The time now is 06:07 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