I have an old HP 3311 function generator with 600 Ohm output impedance. My GW Instek AFG 2112 does not function anymore.
Have to detect what its trouble is.
At last I managed to get things properly measured. Got the problems with my Instek AFG 2112 solved (a very STUPID thing don't want to mention it, too embarrassing 😡).
This is the used setup: Signal generator > Hagerman iRIAA2 inverse filter > my RIAA equalizer pcb > Marconi TF2600 Voltmeter at the Equalizer pcb out and a scope as signal
monitor.
Adjusted the signal gen. sine wave amplitude such that at the RIAA equalizer output appears 500mVrms at 1 kHz 100kOhm load. Then using the 1kHz-500mVrms as 0 dB reference out:
20 Hz > 1kHz : +1.6 dB
1kHz > 25kHz : -1 dB
This is the used setup: Signal generator > Hagerman iRIAA2 inverse filter > my RIAA equalizer pcb > Marconi TF2600 Voltmeter at the Equalizer pcb out and a scope as signal
monitor.
Adjusted the signal gen. sine wave amplitude such that at the RIAA equalizer output appears 500mVrms at 1 kHz 100kOhm load. Then using the 1kHz-500mVrms as 0 dB reference out:
20 Hz > 1kHz : +1.6 dB
1kHz > 25kHz : -1 dB
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The PDF article on this page explains briefly how to use square wave testing For RIAA response assessment. It really does give you a lot of information you can’t get from a sound card and it’s very sensitive to frequency anomalies at HF 9ie > 20 kHz) where you still want well behaved response:-
https://hifisonix.com/projects/inverse-riaa-network/
https://hifisonix.com/projects/inverse-riaa-network/