Tone generator output Voltage for amplifier measurement? - diyAudio
Go Back   Home > Forums > Design & Build > Equipment & Tools
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Equipment & Tools From test equipment to hand tools

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 28th June 2010, 09:12 AM   #1
diyAudio Member
Join Date: Jun 2010
Exclamation Tone generator output Voltage for amplifier measurement?

Hello,i'm viewing this forum for whole years,really great work!

Since i want to measure an amplifier and i don't have a function generator i'm using my sound card to do that.

The problem is the following:

I have a lot of software tone generators set on 3db but i'm getting a different voltage from them.

For example if i set the NCH Tone Generator to 3db and the sound card to 100% i'm getting on the sound card's output about 445mV RMS,but if i use another tone generator i'm getting another number lower or higher.

The question is,how much Volts RMS am i supposed to have on the amplifier's input for a proper measurement? Is the correct voltage 2.87v RMS?

Also on the max volume i'm getting a stable AC Voltage,am i have to convert this Voltage to Volts RMS?

Thank you very much.
  Reply With Quote
Old 28th June 2010, 09:30 AM   #2
AndrewT is offline AndrewT  Scotland
diyAudio Member
Join Date: Jul 2004
Location: Scottish Borders
insert a pot between the PC and the amplifier.
Use the pot as an analogue adjustment.
Arrange a -20dB switch (9k & 1k) that outputs just 10% (precisely) of the pot signal and then flick the switch to get full signal.
This is particularly useful when doing power testing when everything gets very hot very quickly.

I would aim for a maximum test signal of 2Vrms switchable to 200mVrms and then the pot to reduce that by a further -40dB giving a range of test signals from 2mVrms to 2Vrms

Keep the PC output near maximum all the time and don't go too high in frequency. The output is far from sinusoidal when frequency rises and digital attenuation is applied.
regards Andrew T.
Sent from my desktop computer using a keyboard
  Reply With Quote
Old 28th June 2010, 09:44 AM   #3
diyAudio Member
Join Date: Jun 2010
You just don't know how much i appreciate your instant answer! A big THANKS!
  Reply With Quote


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
Adjustable octave warble tone generator percy Everything Else 8 3rd December 2010 04:00 PM
Voltage Measurement mr2racer58 Tubes / Valves 1 21st March 2010 04:52 AM
Amplifier theoratical max rated output power based on supply voltage wwenze Solid State 13 26th September 2009 05:02 PM
Tone Generator - Multiple Tones and Variable Amplitude percy Equipment & Tools 15 20th December 2007 02:17 PM

New To Site? Need Help?

All times are GMT. The time now is 12:50 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2