Threshold voltage?

[gutsofgold]

Diodes have a certain threshold voltage, meaning it takes a certain amount of voltage for the signal to be passed and be "clipped"...right?

So more diodes in series with each other = greater voltage needed to get a clip, meaning less distortion or overdrive?

I ask because I'm putting diodes in my tube screamer and having two 1N4148 on one side and just one on the other leaves me with a really really really mushy, compressed overdrive sound. I'm trying to hear that sweet asymmetrical tone but its just not coming through.