That looks like a handy little unit!
The ones I've checked are inconsistent by brand, date, etc.
I have two old 5401 pulls, they're not top-notch linearity.
Results apply to the device tested, not to all other parts with same type number. If you want confidence you need to test each part that is actually used. Another unit from same brand can be different and between brands vastly different. Several processes may meet the min/max specs and be used interchangeably.
Different requirements.
1. For the input (low-noise) stage, the microcurrent mode, low voltage
2. For the stage Vas, low distortion in the current range and a wide voltage range. Low-noise.
3. For the driver, the gain plateau and decay with increasing current.
4. For output transistors, constant gain in the operating current range.
1. For the input (low-noise) stage, the microcurrent mode, low voltage
2. For the stage Vas, low distortion in the current range and a wide voltage range. Low-noise.
3. For the driver, the gain plateau and decay with increasing current.
4. For output transistors, constant gain in the operating current range.
