New CineMag CM-2800g. Custom wound for me, never used, new in the bubble wrap. 1 pair. Specs: 2:1, 20Hz to 20KHz, Air gap for 30mA unbalanced DC. Designed for use with 6BX7 as driver for 300B. New $150.00 asking $100 obo.
AES PT-157. Specs: Nickel core, Primary 10K 10mA dc, secondary 90K. Used but good condition. $40.00 obo
AES PT-157. Specs: Nickel core, Primary 10K 10mA dc, secondary 90K. Used but good condition. $40.00 obo
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It was designed to use with the 6BX7 or 2A3 to drive a single end 300b. That puts it in the neighborhood of 2K~2.5K. Cinemag used the PSpice model data for both when they designed it.
No, not the AC impedance, if you put a meter across the leads on the primary, what does it show?
Yes. This is a schematic for a 6EM7 amp. I was going to use a single 6SL7 section input tube and the 6BX7 single section as the driver. The voltages and currents would remain the same. Cinemag designed the xfmr with PSpice for the 6BX7 at 30ma and the 300b. The Cinemag would be attached as 2:1. I was told this would help push the 300b into A2 for lower distortion. I was also going to use adj. negative bias instead of 300b cathode bias. Hope this helps.
A 30K plate load on the small triode of the 6EM7 is going to dominate how the amp sounds (in a bad way). With a 2:1 IT, just switch the 100K and 30K resistors and all will be well.
But in this case, with a 6BX7 that was planned, would you have had the same concern?
The schematic was just a starting point. I should clarify. The circuit would need to be adjusted for the 6SL7...different plate and cathode resistor (I was not going to use the NiCad battery) and current. The voltage and current (for the 6BX7) would remain the same. The xfmr was designed for the 6BX7 and the cathode resistor would need to be adjusted to set the 30mA current.