MILA-1 question

[Richie Mann]

I've been working on my first electronic tube project for about 8 months now (the MILA-1) and I had a question I was hoping some of you experienced people could answer for me. I used a CineMag CMMI-10B as my input transformer instead of the Beyer and I was told by the CineMag people to replace R4 with a 150K ohm resistor because of the different impedience, and to drop C1 all together. I understand why the resistor was changed, but I don't understand why the capacitor was no longer needed. Can someone please shed some light on this for me? Thank you

 

[shabtek]

zobel network

 

[ruffrecords]

Some transformers have a resonance at a high frequency or a poor response at 20KHz. The RC network on the secondary is intended to compensate for this. The better quality transformers often do not need this and a plain resistive load is all that is required.

Cheers

Ian

 

[Richie Mann]

Thanks - that explains it