Author Topic: Second Build Doesn't Work  (Read 3116 times)

JebemMajke

Second Build Doesn't Work
« on: May 06, 2011, 07:15:59 AM »
I've built npn booster ( http://www.diystompboxes.com/beginner/schem.gif ), and it works. So i decided to build another one, but from a different schematics ( http://www.beavisaudio.com/techpages/HIW/hiw1.gif ), just to see if i have figured out how to read schematics and really to experiment a bit. So I've changed some values. R1=475k, R2=33k, R3=15k ( And also i added a switch so i can take it back to 10k if i don't like the sound with 15k ), R4=466. For transistors I've put two H1815's in a Darlington pair, one measured 330 hfe the other was around 280 hfe witch resulted in 92400 hfe. Used a 250k pot, i had 10k, 50k and 250k pots, no 100k. And for C2 I used Metallized Polypropylene Film Capacitor ( http://img1.topfreebiz.com/o2010-5/Metallized-Polypropylene-Film-Capacitors-Box-Type-MPB--18795563.jpg ) with 0.1 uF value. DPDT switch.

It works in bypass mode but when i turn it on i get nothing.
Please help.