I built an Aikido pre-amp, I am not sure If the left and right channels are balance, sometimes I sense that the left channel is louder, having a room where the left and right sides are not symmetrical makes it even harder. Is there a way to test using a multi-meter if the outputs of my pre-amp are balance?
If all you have is a multi meter then things get a little difficult.
You could apply test tone sweep (mono signal) to both channels and have the DVM connected between L and R outputs. Any difference in AC voltage between the two channels would show as a variation away from zero volts. You need a meter that can respond across the audio bandwidth and that is also reasonably sensitive to do this.
You can also apply spot frequencies (100Hz, 1kHz, 10kHz and 20kHz) and check and compare the actual output voltage from each channel. Accuracy isn't important as you are really looking for differences.
You could apply test tone sweep (mono signal) to both channels and have the DVM connected between L and R outputs. Any difference in AC voltage between the two channels would show as a variation away from zero volts. You need a meter that can respond across the audio bandwidth and that is also reasonably sensitive to do this.
You can also apply spot frequencies (100Hz, 1kHz, 10kHz and 20kHz) and check and compare the actual output voltage from each channel. Accuracy isn't important as you are really looking for differences.
You can use one of the online sine wave generators or an mp3 sine wave sample of 400Hz. Just play it through your pre-amp and measure the output level with the multimeter set to measure AC voltage. This should give you an accurate measure of the output levels of both channels.
Fit a balance control.
It is simpler & cheaper than re-building your house to be symmetrical.
You could swap channels left for right and see if the loud channel changes sides.
It is simpler & cheaper than re-building your house to be symmetrical.
You could swap channels left for right and see if the loud channel changes sides.
do you have an old cassette deck?
they come with meters
feed the same mono signal into the preamp, feed the output of the preamp into the cassette deck, and see what you get
they come with meters
feed the same mono signal into the preamp, feed the output of the preamp into the cassette deck, and see what you get
^^^^^^^^^^ this.
https://www.mediacollege.com/audio/tone/files/440Hz_44100Hz_16bit_30sec.mp3
Set player to Loop or Repeat one so it automatically restarts and you have a continuous tone.