LPB2 problems

[Hydesg]

hi
ive just completed building the LPB2 on the perfboard

problem is that the volume is very soft
and id need to crank up the volume of my amp quite high for me to hear something from the LPB2 pedal

the volume knob on the LPB2 is set to max

any idea whats wrong with it ?

[AL]

Start with the basics. Does your bypass work? Check ALL of your wiring - switches, jacks etc.? Are all of your grounds connected? Are there any cold solder joints? Is the transistor correctly oriented?

AL

[petemoore]

Transistor in there the right way round.
 DMM test the resistors, if you see a smaller value than is called for, being in the circuit may provide an alternate current path, [says nothing without math or one pulled lead] if the measured R value is greater, then there's a too large resistor there.
 I used to forget about forgettin ghte K like for an emitter resistor of 470, I'd sometimes put in like a 470k
 Check the Faq and debugging pages, there's enough info in those to debug most all circuits.
 Battery good?
 That has like 8 parts, so there are probably 1,000 ways to get a miswire..

[Marcus Dahl]

hi
ive just completed building the LPB2 on the perfboard

problem is that the volume is very soft
and id need to crank up the volume of my amp quite high for me to hear something from the LPB2 pedal

the volume knob on the LPB2 is set to max

any idea whats wrong with it ?

Check your ground wirers and go back over your solder conections on your board by reheating them. Most likely you either have a cold solder joint, bad ground conection, or you forgot to conect something. I'm pretty much saying you need to recheck your work.  

[Hydesg]

the transister voltages are

E - 0.3
B - 6.3
C - 8.7

could it be a cold joint around the transistor area?

[petemoore]

..what's the voltage of the test battery?

[Hydesg]

the voltage of the battery is 8.7 v

[Hydesg]

i rebuilt the whole circuit again with new parts

seems like im having trouble making it work
=(


now it reads

e - 0.3
b - 0.77
c - 8.7

battt - 8.7

i double checked all connections and its still the same
im using

a 2n5089 trans from fairchild

[petemoore]

Well on the first one the Base looked maybe a little high...
 Not sure exactly what the voltages should be, but I would check around the base of the transistor for a missed R value etc.
 On the second one the base voltage is low...I  belive the base should sit about half way between where the emitter is [voltage wise] and the collector voltage...Geo has the lowdown on biasing transistors...
 Witha small R from emitter to ground, the emitter should be reading just above ground, it is.
 The collector is reading exactly what the battery is...seems like it would be sllightly lower with the collector resistor on it.
 for the Base to be able to swing positive and negative, it should sit somewhere close to between the emitter and collector voltage...
  DAFT...memory...
 Disregard the above and read at GEO for how to bias a transistor...
 Before I do. It is easy to err.

[Marcus Dahl]

i rebuilt the whole circuit again with new parts

seems like im having trouble making it work
a 2n5089 trans from fairchild

You might want to try a 3904 instead of the 2n5089 not that that is the problem. Check a couple other schematics of the LPB circuit. You may have one that is in correct. I still think that you are not connecting something.