| Application | KT66, 6550, 6CA7, 6L6 |
| Primary Impedance (Zaa) | 2756 ohm |
| Secondary Impedance (ZL) | 5 ohm |
| Turns Ratio Np/Ns (4 ohm secondary) | 23.48 |
| Ultra Linear Tap | 70 |
| -0.1 dB Frequency Range (flf) | 1.8 Hz - 63.6 kHz |
| -1 dB Frequency Range (fl1) | 0.7 Hz - 120.6 kHz |
| -3 dB Frequency Range (fl3) | 0.4 Hz - 187.4 kHz |
| Nominal Power, RMS (pn) (note 1) | 70 W |
| Full Power Bandwidth, -3dB, starting at (fu) | 22.7 Hz |
| Total Primary Inductance (Lp) (note 2) | 490 H |
| Primary Leakage Inductance to Secondary (lsp) | 2.6 mH |
| Effective Primary Capacitance (cip) | 558 pF |
| Total Primary Resistance (Rip) | 173.7 ohm |
| Total Secondary Resistance (Ris) | 0.168 ohm |
| Insertion Loss (Ilos) | 0.4 dB |
| Tube Plate Resistance (rp) | 1 kohm |
| Q-factor 2nd order HF roll-off (Q) (note 5) | 0.64 |
| HF roll-off Specific Frequency (Fo) (note 5) | 209.4 kHz |
| Quality Factor (Lp/Lsp) (QF) (note 5) | 188,510 |
| Quality Decade Factor (QDF) (note 5) | 5.27 |
| Tuning Factor (TF) (note 5) | 2.482 |
| Tuning Decade Factor (TDF) (note 5) | 0.395 |
| Frequency Decade Factor (FDF) (note 4, 5) | 5.67 |
