Hi, what I miss in the software QA40x and QA40xPlot is the ability for adjustable phase setting the generators Gen1 and Gen2. Did I miss something in the usage tutorials?
Hi @Sven, there’s not a way to set the phase relation between Gen1 and Gen2. Of course, they’d have to be locked at the same frequency. What application are you thinking of?
Hi Matt, one application is to verify or calibrate my audio phase meter. Further to generate an inverted signal in order to create cancellation at the outputs of e.g. an amplifier. This would show differneces in behaviour due to null-testing.
@Sven I purchased an inexpensive ($95) 20Mhz signal generator, East Tester ET3320C, which has dual outputs and lets you set the phase of each output- that might help you.
Hi @VAR and @Sven, ok, so this would be the ability to specify a phase offset between left and right, not so much between GEN1 and GEN2. Makes sense
Hi, yes, this would be sufficient. For the null-test I can use + and - of the balanced output and feed both inputs of an amp which gives the 180 deg phase offset aka polarity change. I have free software which can define phase difference between left and right signal. But these work only with the PC internal sound chip beause it cannot use ASIO for an external USB DAC. I like the QA403 much and want to use it as my primary meas instrument.
Unless your amplifier is a BTL output stage, you can just take the two spkr hots (+) and drive both channels with the same signal. The result is a null.