Local negative feedback derived within the cryogenic stage from the outputcurrent of a voltage-biased SQUID series array is used to linearize the fluxresponse and to simultaneously approach the noise matching resistance of theroom temperature readout amplifier. The flux noise level of the SQUID array was0.5 μΦ0 Hz−1/2 in open loop and0.8 μΦ0 Hz−1/2 in the feedbackarrangement having a 2.2 Φ0 peak-to-peak flux locking range. The noise level degraded to2 μΦ0 Hz−1/2 in an arrangementwith a 7Φ0 locking range. Very good linearity was observed in the feedback system regardless of themodest loop gain, owing to the open-loop SQUID characteristics which are more linear in thevoltage-biased case than in the current-biased case. Upward and downward slew rates of 3.4 and1.2Φ0 µs−1 were recorded which, however, do not represent ultimate limits of the approach. Localfeedback schemes are reviewed and their effect on the linearity of a SQUID system isdiscussed.