• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

Interstage Transformers

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
 

Attachments

  • CineMag1.jpg
    CineMag1.jpg
    96.6 KB · Views: 722
  • CineMag2.jpg
    CineMag2.jpg
    96 KB · Views: 717
  • PT-157.jpg
    PT-157.jpg
    198.2 KB · Views: 724
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.
 

Attachments

  • 6EM7_300b_SUPER_AMP.pdf
    28.5 KB · Views: 115
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.