preamp/amp build

[Jeffsg605]

I want to build an amp from scratch and I want to include a couple distortions, clean, and an effect like chorus or flanger built into the head with controls to switch between them.  Would it be best to put these effects inbetween the preamp and amp or before the preamp like effects pedals are?  Thanks.

[defaced]

With distorted tones, modulation usually comes after the distortion.  If you're going to use the preamp for distortion, then I'd place them between the preamp and the power amp. 

[Astronaurt]

Would the amp you're building be Tube based or solid state? You usually want to have Tubes running on pretty high voltage so if you want to put on board Chorus or Flange you'll need to attenuate the signal after the pre-amp, run it through the effects circuitry, then boost it back up to a level suitable to drive the power amp. This could either be done in series with the Signal path or in parallel, If you do it in parallel then it's extremely easy to take the extra step to put an effects send and return which is always nice to have.

Alternatively if you could go the route of building a solid state clean Pre-amp (which are alot more forgiving on voltage), then run it through a distortion circuit in series, and then to your chorus and flanging circuits in parallel. That option would probably be a fair bit less complicated or dangerous.