transistor saturating? halp! :D

Started by Mugshot, October 14, 2009, 11:48:48 PM

Previous topic - Next topic

Mugshot

a few months ago i built a trotsky overdrive using 2n3904 tranny but the gain control is on the emitter unlike Dano's and i used a 3.3k resistor to bias the collector. voltages are fine.

it gives a fair amount of level boost, and can easily be used to boost another pedal after it for more gain (trotsky > dirt pedal > amp)

however, the reverse doesnt seem to give me good results; i.e., when the trotsky is boosted with another pedal (such as another dirt before the trotsky) like this:

dirt pedal > trotsky > amp

actually any pedal just above unity gain - even the phase 90 clone i have - when placed before the trotsky makes the trotsky saturate (im not sure about the term). i mean the Trotksy distorts but in a bad way. it sounds too flabby/farty.

a month ago i built a pedal similar in concept to the trotsky but i employed a different approach. and yes, i had the same problem as with the trotsky *sigh*

im thinking the transistor can no longer handle the excess signal, idk. any ideas why? thanks a lot!
i am what i am, so are you.

Mugshot

in addition, the voltages (as far as my memory is concerned :D)

C - around 4-4.1v (adjusted using a 10K trimmer)
B - 0.5V(?)
E - 0.1(?) can remember well, but it was well within the range for an NPN to amplify. a 1K resistor from emitter to ground raises the collector voltage to 4.3V
i am what i am, so are you.