Here is a guide on how to measure source output impedance and unloaded max voltage accurately and at a very low price (sub 30 usd).
My own measurements are in my database.
Calling the reviewers here to get their hands on this so we can have more measurements out there besides just ASR (that does not always specify the OI for some reason) and L7Audiolab.
@VIVIDICI_111
@Jaytiss
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