Low output on mosfet booster. Base lower then emmiter.

[demonstar]

I'm using a 2n3904 transistor for the millenium bypass which I think may be the problem. I'm not sure this is suitable. I'll try another.

[petemoore]

  Mil Bypass won't work without the right transistor.
  i'm not following real close, sometimes it's better to debug the 'circuit' with no bypass switch, in/out/dc jacks and whatever else isn't necessary, until the circuit is biased and known working.

[demonstar]

Thanks Pete.
It's all working except the indicator LED and I believe it's down to the transistor so the only JFET i can get hold of local is th BF245C so I'm going to try that. I believe the thing that I've got is no use at all. When I started this build I didn't realise there were so many different types of transistor. I think I'm gonna get a library book on them and learn.

The booster sounds great though and I'm so glad it's working! I'll bear in mind what you say about getting it working first for the future. This is my second build and at least I had the sense to test it before I put it all in the box this time.

What does everybody mean by the circuit is "biased" please? I keep hearing this but don't understand what it means.

[GibsonGM]

'Bias' just means you're putting the transistor/FET/Opamp or what have you into the correct operating region.  Take an opamp...many schematics require you to use a +9 and -9V split power supply (2 9v batteries). 

1)  This is so the signal, which is approx. an AC sine wave, can be amplified correctly.  The signal might go from 0 to +150mv, back to 0 and then to -150mV...so, when amplified X10, you need to have +1.5 and -1.5 volts available for the signal to 'swing'.  If you don't, it will clip - sometimes this is good, as in the  MXR Dist +. 

2) By sending the non-inverting input of an opamp about 1/2 your power supply voltage at a low current, you 'raise the bar' the opamp is working with.  This voltage mixes with your incoming signal via the principal of superposition.   Now the signal will swing something like 4.5 volts to 7 volts, back to 4.5v to 1v.  This is biasing the opamp, and works very similarly with transistors and what have you.  Generally it's 1/2 battery voltage, and is called "bias", "Vref", "Vbias", "1/2 V" and other terms.  The great thing about this, is that you now only need your regular 9V power supply!

3) A device which is "misbiased" will behave in an undesirable way...distortion, oscillation, low signal, no signal.  Some circuits need a different, more complex ratio of voltages, such as the fuzz face.  Splatty sound tells you it's not biased correctly.  Generally fixed with a DMM and trim pots...

Searching on google for basic opamp tutorials will show you more ;o)  Hope this makes sense and helps you out!

~Mike