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Mangler, first build, odd Bias voltage reading - help pls

Started by AJPennypacker, January 26, 2016, 05:23:39 PM

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AJPennypacker

Hi all, built the PNP Mangler, it works (after a few fixes) but when trying to bias my voltage reading on the pad is btwn -.23 and -.14 can't get it to -4.5, any help appreciated.

madbean

Possibly you have used a wrong value for R3 or R4. It should be 220R and 470R, resp. What color are the bands on your R3 and R4 resistors? Also, did you use the 20k trimmer, or a different value?

AJPennypacker

Used a 20k trimmer, upped the R4 to 1k to increase volume (as per another post). R3 is 24k; came with the PNP's, indicated as the correct R3 for those transistors which now seems a bit extreme considering it should be 220R. I'll swap it for a 220 and see if that clears it up.

Thanks for the help


AJPennypacker