Ok, experienced pedal builder stumped....

[casey]

I cannot seem to figure this one out....

I have an overdrive and a boost in one box.  if I wire the overdrive first and feed it to the boost, the two effects will work independently and together.  but,  if i wire the boost first and then the overdrive, they will both work independently, but not together.  here's the wiring diagram ( both switches are 3pdt but i have left out the led part for clarity):


                 overdrive in - o      o - overdrive out                         boost in - o       o - boost out

  feed from other switch - o      o - output jack                         input jack - o        o - feed to other switch

                                     o------o                                                             o--------o


the box has 2 volume controls....one for the boost and one for the overdrive.  and it also has a gain knob for the overdrive.

what am i doing wrong?  if they are both switched together, they will not work.  but they will work independently.  also - if i change around where the effects ins and outs are on the switches...they'll work together as they are supposed to....but i really would like to place the boost before the overdrive.

any suggestions, as im all out of ideas....?? 
                                                 

[R.G.]

I would first look at whether there was DC coming out of one of the effects and whether there was DC coupling at the input of the other.

You don't say what "not work" means, but having a condition where one misbiases the other could qualify.

[antojado]

How can you tell they aren't working together when the boost is in front of the od? Do they not make any noise at all?

[casey]

thank you for your reply...   they are both the exact same circuit but the boost is without the clipping stage.  what i meant by they are not working right is that both effects will work separately, but not toghether....  if i feed the overdrive into the boost they will both work independently and together...but if i try to feed the boost into the overdrive (boost first) they will not work at the same time, but will work independently... 

[casey]

i forgot to mention that both are ic based circuits....and not transistor.  i will check the d.c....  didnt think of that originally because both circuits are the same....they will work together with the o.d. into the boost, but not the other way around.  i forgot to mention that i can hear a very faint sound with the volume of the first effect at around 7 0' clock (just barely engaged).

[Mark Hammer]

Um, is it possible that what you are experiencing is the simple fact that using clipping diodes will set a ceiling on the output level such that when you feed a booster into the overdrive you don't hear any increase in the overdrive's output when you diddle with the booster controls?  If your overdrive goes to the booster, which sets no fixed ceiling on the potential output level, you will be able to make the distortion output louder, while flipping the order does not permit that.

Is that what we're dealing with here?  Or does your use of the word "work" mean something different?

[inquebass]

I am a novice pedal builder, but a fairly exp'd engineer,(<---disclaimer).

Try scrapping the dist circuit save for the diode, wire a pot to the circuit and the diode, and then you will be able to mix the boost/OD signal. If you just want switching, replace potentiometer with switch.

just my .002 cents.