Is it a 1khz sine wave I need or what hertz sine wave do I need to measure the preamp output voltage of a head unit ?
Not all meters have a flat frequency response across the audio spectrum. Unless you confirm that your meter reads accurately at the higher test frequency, use 60Hz.
Drive the output to as close to clipping as possible and measure across the center conductor and the shield. ACV.
Drive the output to as close to clipping as possible and measure across the center conductor and the shield. ACV.
Whatever it takes to reach clipping. 0dBfs will max out the digital section but the circuit beyond that may have gain so a lower level may be able to drive to clipping.
Ok so I’m gonna check the voltage on the preamp output of head unit with a 60hz sine wave . Then I’m gonna check the symmetry next it says use a 1khz sine wave should I stick with the 1khz for the symmetry or use a different test tone
If you confirm that your meter reads flat from 60Hz to 1k (or whatever range you want to use), you can use any frequency.
Do you have a sine wave generator?
Do you have a sine wave generator?
Drive the output to 2v (measured on meter, 60Hz).
With your meter and your scope connected across the generator, sweep from 20Hz-20kHz. On the scope, you should see a VERY consistent level. Your meter will vary. The frequencies it reads the same as at 60Hz will be reliable.
With your meter and your scope connected across the generator, sweep from 20Hz-20kHz. On the scope, you should see a VERY consistent level. Your meter will vary. The frequencies it reads the same as at 60Hz will be reliable.
I played a 60hz test tone through my head unit claiming to be 4volt preout .
The volume reaches max at 35 I had it set to 31 and I got 1.2volts output . I then played a 1khz test tone and only got 2.3 volts .
Any ideas what would cause this ?
The volume reaches max at 35 I had it set to 31 and I got 1.2volts output . I then played a 1khz test tone and only got 2.3 volts .
Any ideas what would cause this ?
Did you do a sweep test on your meter to see how wide the meter read flat?
Make/model of the head unit?
Did you use the start of clipping as the point where you stopped increasing the volume?
Make/model of the head unit?
Did you use the start of clipping as the point where you stopped increasing the volume?
Yes I did the sweep test and the meter read 2 volts at 60hz when I Used my sine wave generator and scope .
Yes I used the start of clipping at the point .
The headunit is an Aloine ILX-W650.
The EQ settings are all flat on the headunit not sure if that makes a difference
Yes I used the start of clipping at the point .
The headunit is an Aloine ILX-W650.
The EQ settings are all flat on the headunit not sure if that makes a difference
With your scope set to 1v/div and 2ms (probe set to 1x), drive the output to 1v on the meter (60Hz) and post a photo of the scope display.
Post a second 60Hz waveform image with the head unit clipping (no changes to the scope settings).
Post a second 60Hz waveform image with the head unit clipping (no changes to the scope settings).