Strictly Matched Pair (2PCS) SONY Original SIT (V-FET) 2SK79 (120V, 200mA, 750mW) with curve data

This listing is for an original pair of Sony SITs (2SK79) manufactured in the 1970s, supplied as a strictly matched set of two with full curve-tracer data. The two devices are matched so precisely that the gate-voltage difference remains within ±0.05 V across the entire measurement range of the curve-tracer—not just at a single operating point. This means the matching accuracy is far superior to the common practice of using only an Idss measurement at one point.

One of the greatest virtues of this device is that it exhibits a beautifully triode-like transfer curve even without negative feedback. However, unless sufficient NFB is applied, any inherent device variations will directly appear as gain and distortion mismatches between the left and right channels of a stereo amplifier. Yet relying on negative feedback would defeat the very sonic qualities that make this device special. For this reason, achieving perfect matching is especially critical when using these SITs.

The pair offered here is perfectly matched in that regard.

The curve data shown in the photo is just a sample. Since each device has slightly different characteristics, the actual curves will not be identical to those in the photo.