Metropoulos Forum

I am trying to calculate the best NFB for my NMV 1959 build

I see 8 ohm tap 47k was more common. I am using EL34 tubes

Would the 4 ohm and 100k give me more dirt?

Thanks in advance.

Dan

Ninety-nine percent of the 1969 through 1970 100w Super Lead amps had a 47K from the speaker output jacks as a NFB setup. In 1971 you start to see some variance in the NFB setup for the Super Lead's (i.e. 47K from 8ohm tap). As '71 progresses you see the 47K/4ohm arrangement and then eventually the 100K/4ohm setup comes into play late in 1971.