JAY X said:Hi!
As i am testing my summing mixer, i have to test the maximum input and output levels it can achieve.
¿is it ok to test this levels with a 0dbu test signal level?
¡Thank you!
jay x
0 dBu is a nominal -4 VU operating level.JohnRoberts said:0dBu is a nominal 0VU operating level.
JAY X said:As i am testing my summing mixer, i have to test the maximum input and output levels it can achieve.
¿is it ok to test this levels with a 0dbu test signal level?
JAY X said:Is there a formula to calculate the input headroom of an amplifier?
I will ASSume you are not asking a trick question.JAY X said:Hi!
Ok, the fact is that i try to measure the maximum input level with the mixer in the true RTA anlyzer loop, and this does not work.
Because i'm limited to the maximum input level that my audio interface (behringer UMC 1820) can cope. Red lights lit with:
1469mv input RMS / 8.58dbu peak / 5.58dbu RMS. So, I have to measure the output voltage and distortion right at the output of the first stage.
¿Is there a formula to calculate the input headroom of an amplifier?
jay x
You started with a simple question (maximum level), and made it complicated ;DJAY X said:¿Is there a formula to calculate the input headroom of an amplifier?
abbey road d enfer said:You started with a simple question (maximum level), and made it complicated ;D
As others have mentioned, headroom implies two values, one measurable and the other arbitrary.
A typical input stage has its max input level governed by the rail voltage and its gain. An opamp with +/-15V rails can deliver +20dBu; at unity gain, the max input level is thus +20dBu. Make it 10dB gain, and the max level drops by 10 dB, make it 6dB attenuation, max input goes to +26. That's the easy and measurable part.
Headroom involves the definition of a nominal operating level.
If the nominal is +4dBu (0VU), the headroom is 16dB for unity gain, but if the operating level is the "Tascam" level (-10dBv=>-7.8dBu), the headroom becomes 27.8dB.
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