ricothetroll
Well-known member
Hi,
I've come accross some issue I've never had (noticed ?) before : while testing the output of an Eden 500W bass amp (transistor) with my resistive dummy load, I've noticed some groth distotrion on the waveform. Seemed strange as the amp sounded pretty OK when loaded with a speaker.
I've plugged headphones on it (headphone out is an attenuated version of the power output) I've noticed that it was when I put my 1/10 probe on the dummy load that the distortion appears. I've then configured my scope (Tek 466) for differential measurement (CH1 minus CH2) and then could see a perfectly nice waveform.
Have you guys ever experienced the same thing ? I'd like to keep use of the 2nd channel of the scope while doing those measurements to be able to monitor the input signal along with the power output, so I though of building a diff input. I don't need 100MHz of BW, but 1MHz could be nice to be able to check for oscillations. Would a THAT1200 do the job ? Could the isolation be sufficient ? Of course I'd use it with a 1/10 probe to prevent overloads.
Best regards.
Eric
I've come accross some issue I've never had (noticed ?) before : while testing the output of an Eden 500W bass amp (transistor) with my resistive dummy load, I've noticed some groth distotrion on the waveform. Seemed strange as the amp sounded pretty OK when loaded with a speaker.
I've plugged headphones on it (headphone out is an attenuated version of the power output) I've noticed that it was when I put my 1/10 probe on the dummy load that the distortion appears. I've then configured my scope (Tek 466) for differential measurement (CH1 minus CH2) and then could see a perfectly nice waveform.
Have you guys ever experienced the same thing ? I'd like to keep use of the 2nd channel of the scope while doing those measurements to be able to monitor the input signal along with the power output, so I though of building a diff input. I don't need 100MHz of BW, but 1MHz could be nice to be able to check for oscillations. Would a THAT1200 do the job ? Could the isolation be sufficient ? Of course I'd use it with a 1/10 probe to prevent overloads.
Best regards.
Eric