Telepathy club
New member
I’ve recently built a mofeta preamp. I’ve done the C8 mod John from eae suggested. Replacing the LPF C8 from 680pf to 270pf. But my build has either way too much low end or an attenuated high end. Everything works. The eq sweeps a decent amount for all bands but doesn’t overcome the massive low end signal. The 2n5457 are biased to 4.5v. The eq works. I’m just getting something like +10 - 12db for everything below 400hz. I am using a tle2072 instead of ye ol tl072 but that’s should just drop in and have lower noise. If I record the signal I can add +10db with an eq to everything above 1k and I can see I have highs in the signal up to about 7.5-8khz. So I think I just have wayyyyy too much low end even with the control at 0. Turning up the bass knob I just get even more bass. Any suggestions as where to start probing? Its almost as if I need to tilt the entire eq at 1khz +6db above 1khz and -6db for everything below 1khz.