J&K for 212E Parallel Push Pull Output Transformer
~ 1800$US not ship includeLevel 3 Nanocrystalline Double C Core Output Transformer for 212 Parallel Push Pull
Parameters
Output power: 350W (@20Hz)
Measured in circuit response: (8 Ohm, 1W)
* 20Hz (-0.17dB)—1 kHz (0db)—20 kHz (-0.18dB)
* ~5Hz – 100 kHz -3dB
Primary impedance: 5KΩ PP
Secondary impedance: 0-4-6-8Ω
Core material: Custom made Nanocrystalline SiFe cut core
Primary DCR: 62.2Ω (62.1 Ω) (P-P, 6℃)
Secondary DCR: 0-4Ω: 0.18Ω; 0-6Ω: 0.22Ω; 0-8Ω: 0.25Ω
Primary inductance: 58.5H (59.1H), at 20Hz, 5Vrms
Max primary current: 600mA
Efficiency: 0-4 (>93%), 0-6 (>93%), 0-8 (>94%)
Weight: ~20KG/pc
Note: P1 & 8Ω are in phase
212 PPP OPT was designed with 350W at 20Hz. Actual power rating at 30Hz is over 500W. In order to increase the core's Bmax, magnetization saturation (maximum flux density), a calculated precise air-gap is inserted into the core to sustain such power output at 20-30Hz.
The low frequency response of this output transformer is not limited by the primary inductance, but by the core's Bmax, magnetization saturation (maximum flux density), to sustain the flux density at such power level. We lowered the primary inductance knowingly to counter such effects.
The in circuit measurement below has proven our theory and the low frequency response is as good as with high primary inductance, and yet, our output transformer can perform as good as small signal results at full power, as required by the user's demand.
This is done here, as well as in our ALIS-5SE Ultimate OPT for 300B or 2A3 to improve the performance and power handling, yet retain the low frequency response, where primary inductance of18H result is as good as 28 or 34H at actual circuit.
