Cupcake problem: boosting, & no response from trimpot

[findo]

Hi, I've tried searching for an answer to my problem, but no luck..

I'm trying to build a Cupcake (etched the board myself) but the trimpot doesn't do anything.
There is a signal coming through, I'm getting a a noisy boost, (the level pot is working - even dialed down to unity volume, there is dirt in the sound).
The odd thing is that disconnecting the trimpot doesn't change anything, nor does taking the transistors out - the dirty boosted signal still flows. I even tried taking the 3. hole from the trimpot space and connecting directly to the 1, which should short the signal, right? (again no change).

I had to substitute parts (local german store never has the exact parts!), and just went with what the guy at the store suggested:

IC - N1436
Transistors: BS107 & BS170

Any ideas?
Thanks!

[midwayfair]

Your transistors aren't correct. You've used a BJT (BC107) and a MOSFET (BS170). Neither will do what you need them to in this circuit.

I can't find the IC you named, but you need to make sure it's a dual op amp, and check the pinout against the datasheet to make sure it's the same as the 4558.

That failing, there are MANY online parts retailers available to continental Europeans that will have the proper parts, including Banzai Music, which is in Germany.

[findo]

Thanks! I've just ordered the right parts from there... shame my local place gave me the wrong stuff. I guess I should learn more about the parts so I know when it will fit or not, hey..