This papers describes a new, fast and economical methodology to test linear analog circuits based on adaptive algorithms. To the authors knowledge, this is the first time such technique is used to test analog circuits, allowing complete fault coverage. The paper presents experimental results showing easy detection of soft, large-deviation and hard faults, with low cost instrumentation. Components variations from 5% to 1% have been detected, as the comparison parameter (output error power) varied from 300% to 20%.