Associated Test Equipments:
Hameg HM-504 50MHz 2CH Oscilloscope
Escort EFG-3210 2MHz Sweep/Function Generator
Tenma 72-960 LCR Meter
Fluke 19 Digital Multi Meter
8 ohms Dummy Load

We take great care to provide the most accurate numbers/figures according to the tolerance of the test equipments.
1) Primary Inductance (Tested at 1KHz and 120Hz) in Henry indicates transformer capability of producing low distortion at low frequency. Higher figure means the better bass response with less distortion.
2) Leakage Inductance causes roll off at high frequency. The lesser figures represent better quality output transformer.
3) Quality Factor figures derive from Total Primary Inductance divided by Leakage Inductance. The higher figures represent high inductance with low leakage. (better quality)
4) Primary Capacitance causes the transformer to resonate at certain frequency and also cause the anomaly frequency response. The lesser figures are better.

The Frequency Response Testing according to Fig.1 represents the ability of each transformer to perform under real working condition with 70mA unbalanced DC at relatively high power level (18Vp-p output or 5 Watts RMS to 8 ohms load).

The Pulse Behavior (square wave) Testing according to Fig.2 represents the ability of each transformer to response to perfect square waveform. Since square waveform composes of fundamental frequency plus indefinite number of harmonic 2nd, 3rd, 4th, 5th and so on. This test puts transformer to its extreme condition. Output Transformer must handle high number of harmonics at one pulse cycle and will show out its unique characteristic. Good transformers could be observed by smooth waveform with minimal raise/fall time. Good transformers also exhibit less ringing behavior even at high power level.