neovibe only works when speed pot is cranked

[zolee]

Hi everyone,

 I just finished my neovibe according to the plans posted at generalguitargadgets. The pedal sounds great, only it cannot produce slow oscillation. When I turn the speed pot ccw, it acts as the depth pot: oscillation evens out, the bulb is glowing. For this reason only a very fast speed of oscillation can be dialed in, making this great sounding pedal pretty useless.
I also observed that when I turn the power on, the lfo produces a few slow flashes, but it evens out then. Can anyone help me? Thanks in advance for your help.

[R.G.]

Conditions where a univibe-style LFO (includes the NeoVibe) works only under certain conditions or only on transients are usually where the two LFO transistors don't have ...quite... enough gain. Swap another transistor for one of them. Put in a 2N5088 for the first one if you have it.

You can replace both of them with a single darlington transistor like the MPSA13.

[zolee]

thank you very much, R.G. I'll try to fix the problem this afternoon, if I get a little free time.