| Description | Rating | Comments | Part Number |
| Filament transformer | Full wave rectification. Primary voltage 117, taps at 0, +/-5 & +/-10 %, electrostatic shields. | 300-020 | |
| and | 10 VDC @ 26 A (picture of 300-020, 300-041 & 300-030) | ||
| Filament supply inductor, two 304TLs | Internally gapped core, filter capacitor and bracket included. | 300-041 | |
| Filament transformer, | Full wave rectification. Primary voltage 117, taps at 0, +/-5 & +/-10 %, electrostatic shields. | 300-021 | |
| and | 10 VDC @ 13.5 A 16 mVrms ripple (picture of 300-021 & 300-042) (picture of 300-021 terminal board) | ||
| Filament supply inductor, 304TL or two 152TLs | Internally gapped core, filter capacitor and bracket included. | 300-042 | |
| Filament and bias supply transformer, two 866A mercury vapor rectifiers | 2.5 VCT @ 10 A and 250 V. 2 kVDC supply, maximum. (picture of 300-020, 300-041 & 300-030) | Primary voltage 117, taps at 0 & +/-5 %, electrostatic shields. | 300-030 |
| Plate transformer | 1,000 VDC @ 325 mADC when used with inductor assembly below. | Full wave rectification. Primary voltage 117. Equal-resistance secondary halves, electrostatic shields. | 300-010 |
| Plate supply inductor assembly | 35 H total @ 325 mA, DC resistance 165 ohms total (picture of 300-040) | Three electrically separate inductors with internally gapped cores mounted together. Input inductor is layer-wound. | 300-040 |
| Interstage transformer, 6SN7 or 6J5 plate to single class A grid | 150 H @ 10 mA nominal, 20 mA and 0.6 kV maximum (picture with output transformers) (data for 300-160) | NiFe core, 1:1 turns ratio. Removable end-bells with leads from impregnated coil. Optional feedthrough on one end-bell. | 300-160 |
| Interstage transformer, 6SN7 or 6J5 plate to push-pull class A grids | 150 H @ 10 mA nominal, 20 mA and 0.6 kV maximum | NiFe core, 1:2 turns ratio, balanced design, same frequency response as 300-160. Special order. | 300-161 |
| Output transformer, 75TL , 100TL or 152TL | 80 H @ 50 mA nominal, 100 mA and 2 kV maximum (picture of -152, -150 & -151) (data for 300-152) (picture of 300-152 coil) | NiFe core, 50:1 turns ratio. Removable end-bells with solder terminals on impregnated coil. Optional feedthrough on one end-bell. | 300-152 |
| Output transformer, 304TL | 20 H @ 150 mA nominal, 300 ma and 2 kV maximum (picture of -152, -150 & -151) (data for 300-150) (picture of 300-150 terminals) | Internally gapped core, 25:1 turns ratio. Screw terminals at bottom of potted, non-removable end-bells. 19 Lbs. Used in 304TL stereo amplifier. | 300-150 |
| Output transformer, 304TL | 20 H @ 150 mA nominal, 300 ma and 2 kV maximum | 35:1 turns ratio version of 300-150. Nominal 4 ohm secondary. | 300-154 |
| Output transformer, one or two paralleled 304TLs | 18 H @ 300 mA nominal, 500 mA and 2 kV maximum (picture of -152, -150 & -151) (data for 300-151) (picture of 300-151 terminals) | Larger version of 300-150. 20:1 turns ratio. 35 Lbs. | 300-151 |
| Output transformer, one or two paralleled 304TLs | 18 H @ 300 mA nominal, 500 mA and 2 kV maximum | 1:1 turns ratio version of 300-151 for electrostatic speakers. | 300-153 |